90 Responses to “The Calorie Theory – prove it or lose it”

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  1. avatar Tania says:

    The 3500 calorie rule as an average DOES in fact work. What is missing from your article is the total calories obese people are eating I the first place. You do not become obese (in most situations) without an over abundance of calories in the first place.

    The answer to weight loss IS as simple as science. Eat less calories than your body uses and you will lose weight, eat more and gain.

    People need to know their base metabolic rate (BMR) to begin with. My body burns approx 1730 calories a day. That’s just the amount my body will naturally burn without moving a muscle. If I want to lose one pound and never burn any calories through exercise I need to cut 500 calories a day, meaning eat 1230 to lose one pound by the end of the week.

    An obese person’s body may have a BMR of 2500. If they begin eating 2000 a day, they too will lose one pound in seven days.

    The math may not be “perfect” and your body will go through times where it holds water/weight during your cycle or if you’ve consumed too much sodium, or had air travel. The trick is to stick with the calorie count daily and stay committed.

    The trainers on the Biggest Loser will tell you that the contestants lose their weight through calorie restriction mostly. 85% diet and 15% exercise.

    If a person eats 1200 – 2000 calories a day and nothing more, I can assure you they will lose weight. On top of your daily calorie counts, you may eat an unlimited supply of celery/cucumber. (Veggies with very limited calories)

    Lose It, is an app I’ve used for years to help with calorie counting. No one likes to count calories, but this app has almost anything you could find. Supermarket/restaurant items as well.

    Why get so wound up about the specific number and how you want dietician a to stop telling people this works. It does work!!!

  2. avatar Jessica says:

    Sorry, that should read “Banzai Otis” – need an edit button!

    I apologise that for that – that’s a mistake.

  3. avatar Jessica says:

    TBH Banzai, it sounded to me from your post that you were being as antagonistic as you assume I am being. Specifically thanking two people implies that all the other people posting are too stupid for you to bother talking to, particularly when you address everyone else as ‘folks’ in a sentence which sounds so patronising it made me feel sick. That’s how it read and that wasn’t constructive either. I wasn’t actually being antagonistic, I was trying to show that there was a bunch of other questions that this equation simply does not answer. And the point about the starvation issue is why did you bring up the point of a “picture of someone who starved to death” if that wasn’t the image you wanted to put into people’s minds? This is how it reads to an overweight person : “Picture of starvation = someone who lost weight = success!”
    You’re missing the point that many, many diets/medical advice are/is based on this theory – eat less than x and you will lose y in a healthy manner. If it isn’t true, it needs to be abolished. It needs to be chucked away and never brought up again. As long as any person can shout it at the obese, we will always get depressed obese who think that because they haven’t lost Y they are doing something wrong, not that the formula is wrong (or indeed that we shouldn’t have a formula at all).
    Why an issue with the length of the post? If we’re discussing complex issues (and I happen to think these are) it’s going to take a lot of discussion.
    To answer your points (in an opposite way, just how the post turned out):-
    You – Eating fewer calories than you need will result in weight loss*….I’m saying that caloric intake is a dominant factor determining body weight – can we agree on that?
    Me – Sorry, no. “Smash the fat” has already demolished this theory, and I too am showing it to be false with my high fat, low carb diet. I don’t even have to calculate my calorie intake, I just eat the correct food and my weight becomes less. This is not exactly radical stuff, most HF/LC sites will prove that a calorie is not a calorie is not a calorie. Do you agree that 300 calories of sugar are the same as 300 calories of chicken? We can agree that we need to eat.
    2. Putting fuel into a plane or a car is more exact than putting fuel into a biological organism. Can I ask whether you feel that putting half a tank of fuel into a car is a good idea to make sure that the car runs for longer than it would if you put in a full tank? If not, we can see that “Eat less, move more” doesn’t work, let alone provide proof that we can extrapolate some sort of equation from (and in effect you are asking people to move more in the sense that you are expecting people to do the same amount of ‘work” on less fuel).
    You : In fact, I specifically qualified my statement by saying that there are medical exceptions.
    Me : In which case, why are you arguing against the view point of someone who may have medical knowledge? My point is there are more ‘medical exceptions’ (in your terms) than you can happily cover by saying “There are some”.
    In closing, however, I would like to offer my apologies with regards to the assuming you would not be back – you are, and I appreciate it. I find it ironical that the two people you respond to have not been back – this is what gets me, you try to discuss stuff with people who just don’t reply.

    • avatar Banzai Otis says:

      Jessica,

      I don’t know what to say about your first few sentences. I thanked the two commenters because they put their fingers on a central point that I felt nobody else (that I saw) had. All that says about the other people is that I think they missed the point, which is exactly what my words said as well… I literally just got an email that went out to a big chunk of my organization, and it was addressed to ‘folks’. Maybe where you come from this isn’t a friendly term? I don’t know, but I’m just trying to discuss ideas here, not attack anyone. That was the source of my criticism about the length of your email – it was long without addressing anything I actually said.

      I brought up starvation to highlight the fact that, despite all of the complexity, at the end of the day there are some hard laws of the universe at work here. Some commenters (and maybe you?) seem to be challenging the basic physics of the whole deal and suggesting that you can somehow create an energy deficit and NOT eventually lose weight.

      Yes, I agree with the point you are making about different calories, although I would rephrase it to say that the body metabolizes different foods differently (since from an energy point of view all calories are the same). However, I don’t know of any reason that these differences would prevent weight loss or make reasonable approximations impossible.

      I don’t understand your points about fuel in a plane/car. I think MPG is a good example of a simple energy-use metric that does a good job of approximating a very complex system. That’s the only reason I brought it up. Of course using less fuel won’t make a car run longer. What does that have to do with ‘eat less, move more’? And what do either of them have to do with equations approximating energy loss?

      Re Medical: Again, I’m not saying anything about (or arguing against) your particular medical history. And I don’t want to argue my ‘some’ exceptions vs your ‘more’. I’m assuming that the huge majority of people (>90%) don’t have medical conditions which prevent healthy weight loss, but if you have some actual data refuting that I’d love to see it.

      Maybe we could shorten all this down a bit by focusing the point. I’m saying that food is the fundamental, dominant factor in body weight (but not the only). Given that first point, weight loss requires an energy deficit, and therefore healthy weight loss requires some kind of starting point for managing that deficit. This means medical professionals need to quantify it in some way, and the 3500 approach seems reasonable (as an approximate starting point, always taking into account extra-ordinary personal circumstances).

      It seems like you disagree, but I don’t understand your reasoning for doing so.
      What do you disagree with here? How has any of this been demolished or shown to be false?

  4. avatar Eric J says:

    There is no “formula” necessary in determining how much energy is contained in a pound of fat. A pound of fat can simply be burned in a device known as a bomb calorimeter to determine how much energy it actually contains. This is the same type of device used to determine the calories listed on the back of all the packaged products you buy at the grocery store, etcetera.

    While I’m sure the calorific value of body fat varies from person to person, or even from one area of the body to another, I’m also quite sure that 3500 is probably a pretty good average approximation. And while burning an excess of 3500 calories may not result in the loss of a pound of fat in the short term, it will in the long term.

    Eric J
    B.Sc. Chemistry
    C.E.T.

    • avatar Donna Chasteau says:

      Oh phew! Thank you so much! I was dying to post the same. Using words such as ‘nonsense’ in the blog is ridiculous in this instance. The writer is being far too picky. If one were a top athlete then fine, get down to the nitty gritty and fine tune a diet but most people, particularly obese people with health problems who need to lose weight, will most certainly do so using the original equation and wouldn’t dream of reading all this pedantic fluff.

      • avatar Jessica says:

        This formula is used to beat obese people over the head with when they fail to lose the correct amount of weight. The formula is wrong, so why is that so? Why should obese people be judged on how much weight they lose according to a formula which is incorrect? Why should obese people be accused of “eating more than they are telling” by their own doctors when it is not them, it is this flawed equation? Why should obese people be shoved into some sub human category by the smug slim who tell them to follow this formula – which doesn’t work? Suddenly, this “pedantic fluff” becomes a point of such importance to those of us who cannot lose weight in the way that we are scornfully told. I wonder if you understand that a choice between losing weight and losing one’s life becomes a decision one thinks about constantly, because there are people who will assume that this formula will always work, and if it doesn’t, it’s the dieter that is “not doing it right”, not the formula.

        Tell you what; think about these questions for a moment.

        Will an obese person lose more or less weight than predicted by the equation at the start of their diet?

        If your doctor told you that according to his formulas, you would lose 5% of your hair and your actually lost 95% of your hair, would you feel that this was your fault, or the fault of the formula? Would you be concerned or comfort yourself with the thought that at least other people wouldn’t lose as much hair as yourself?

        Does a cheetah, when it’s caught an impala, consider the amount of calories it should be consuming so that it does not put on weight?

        What is the difference between an anorexic on 400 calories a day and an obese person on 400 calories a day?

      • avatar Banzai Otis says:

        Thank you Donna and Eric! The majority of this post and comments seem to miss the point of the rule: It’s a heuristic, folks! It’s not a law of nature (and definitely not a ‘theory’ in the scientific sense). It’s like saying your car gets 30 mpg, so if you go 60 mi you should burn about 2 gal. Yes, fuel consumption is actually a factor of a zillion variables other than distance. Yes, there is all sorts of fancy physics going on, and I could invoke Newton and talk at length about the inaccuracy of applying a linear measure to a non-linear phenomenon (“… but air resistance increases with the cube of velocity! mpg must be baloney!”). I could argue from the margins ad nauseum about how my car gets 1,000s of mpg when I roll it down a hill in neutral. I could even get on my soapbox and demand that we banish the mpg metric until a perfect formula arrives that correctly estimates every milliliter of fuel use, in every car, in every instance.

        None of this matters for the problem at hand. For most people, most of the time, 2 gallons will get you about 60 mi. Unless you are designing a multi-stage rocket, you probably don’t need much more precision. And for most people, most of the time, eating less results in weight loss. We can squabble about how representative the 3500 number is (and I would defer to empirical work on that issue), but all of this other detail about thermodynamics and ‘proofs’ and what-not is seriously overkill.

        With some rare medical exceptions, eat less than you need and you’ll lose weight. Just ask anyone who has ever seen a picture of someone who starved to death.

        • avatar Jessica says:

          No, I’m afraid you’re missing the point. Why is “starving yourself” a good way to lose weight? Why do you feel that starving yourself until you are a certain weight (if you get there before health issues kick in) is a solution, when as soon as you reach your target weight, you either have to keep starving yourself, or look forward to putting on weight. The phrase “starve yourself to death” seems to be fairly indicative of this being a bad thing to do, and yet you still advocate it? Very strange. Do you understand that it is possible for a fat person to die from starvation?

          There are some rare exceptions to “Don’t starve yourself”. For diabetics, starvation can sometimes kick start the body. For me, even low carbing made no difference to my Blood glucose levels until I stopped eating for almost a day. When I began again, I ate only fat and protein. Suddenly, low carbing worked. The 600 calorie diet has had some success with diabetics – I would like to see more research into this, because there does seem to be some evidence that it will work, if there is a sensible follow up to it.

          However, we are constantly hit over the head with this “Eat less than X and your lose y” equation – do you not understand that this is the case? Have you never heard of this equation before? I certainly never want to hear it again. When medical advice is based on flawed numbers, people should be worried. If I had to take arsenic and a doctor told me they had no idea how much I should take, just to take some until it had an effect, I personally would not take any. When did medicine become based on guess work? When you say, “Eat less than you need” can you tell me how to work out exactly how much less I need to eat? How do I calculate my breakfast when I have no idea what I may be doing that day? How many calories – exactly – did I burn yesterday? How many in my sleep? You can’t tell me? So I should just “eat less”. How fast should my weight loss be? Should I eat less so that I pass out and go into a diabetic coma? Should I eat less to the point I start to develop organ failure? How do you know what my calorie intake should be? If I eat very little and I am then forced to be very physical, how much weight will I gain (and I will gain weight)?

          I presume, that from where you are sitting, you know my exact medical history, and how much I do every day, how much I will do over the next few weeks and how much weight I can look forward to losing? How about my colleagues?

          I will check back to see if you have posted any answers but I get the feeling that you don’t really want to understand, you just want to be one of the “Eat less and move more” brigade.

          • avatar Banzai Otis says:

            Jessica,

            Will you take this down a notch or two please?

            First of all, you are arguing against a bunch of strawmen. I never said that starving was a good way to lose weight, or advocated starving to death. I never claimed exact medical knowledge about anyone. In fact, I specifically qualified my statement by saying that there are medical exceptions.

            Second of all, you didn’t address either of my two points. You just said “no”, and then told me I was missing the point (without ever stating what that point was exactly).

            Finally, you capped it all off with insulting my character by suggesting I’m some sort of closed-minded ideologue.

            A flat denial, followed by a list of strawmen and ad hominems longer than my original comment, isn’t exactly constructive.

            I have two points:
            1. The 3500 rule is a rule of thumb. It is an approximation, an average, and so BY DEFINITION is not exact. So complaining that it isn’t exact, or that it should be abolished unless it can be proven exact, is unreasonable. If you take that stance, you would also end up throwing out the equations that tell an airline how much fuel to put in a plane, or tell a breathalyzer whether someone is drunk or not. Both of these are approximations, but the point is that they are good enough for everyday use. Of course 3500 kCal/lb isn’t exact – no average is. This was the point of my mpg example. With averages and heuristics, the question is never whether they are exact or not (because they aren’t, by definition). The question is always about how representative they are and when they are most appropriate to use. And 3500 kCal/lb seems to be representative and useful for most people, most of the time. If you think another value or metric would work better, then THAT is a conversation worth having. Complaining, because you found out that an approximation turned out to be approximate, isn’t.

            2. Eating fewer calories than you need will result in weight loss*. If you are gaining too much weight, you are eating too many*. If you aren’t losing weight, and you want to, then you need to eat fewer*. If you aren’t changing weight, then you are eating exactly what your body needs to maintain that weight*. I only brought this up because some of the comments below (and even yours) seem to call this basic principle into question. I’m saying that caloric intake is a dominant factor determining body weight – can we agree on that?

            If you want to respond to either of those points, I’m happy to try and understand, but please don’t bash me over the head again with a bunch of stuff I never said.

            *Obviously, all of these claims are for most people, most of the time. Outliers with some sort of extreme medical issue will be different – just like a 30 mpg rating is useless if the particular vehicle in question has a faulty fuel pump.

  5. avatar Jane Doe says:

    So, let me get this straight. You say the “3500 kilocalories per pound of fat”-number is wrong, and then you do some maths which shows the number is a decent approximation?
    … Ooook.

  6. avatar julie greenhalgh says:

    hi zoe, before i start love your dog walking blog i do 20 miles approx with the dogs each week, it keeps me sane!!
    anyway, 3 years ago i was 14 st now i am 10st and hve maintained that for 1 year so far. i counted calories mainly because i could do it for free, no books, no monthly payment to weight watchers or whoever. it worked. but looking back i am inclned to think it was a combination of things rther than purely sticking to numbers religiously.
    changing my diet from lots of chocolate to healthy foods not just low fat but real food, getting more active and having the visual affirmation of weighing foods and keeping calorie diary. as i say i never stuck to numbers religiously but i can’t ignore it worked for me
    i no longer count calories or weigh food, i do use a smaller plate which has always helped.
    i do believe people need something tangible to hold to and calories worked it for me but i’m not daft enough to think they were the ultimate reason for success.
    people need educating, it should start in schools, the food industry needs exploding and starting again from scratch! the amount of sugar and excuse language crap that goes in food is unacceptable
    also you can feed a family on good food as cheaply as you can on junk food, we are a low income family and i feed all 4 of us on healthy food as little processed as possible, it can be done
    i fear your mission is going to be a long one but every voice helps :-)

  7. avatar Jim Buch says:

    The issue of thermodynamics in general is pretty screwed up in the media, because the media and millions of regular folks simply don’t understand the subject.

    Millions of people understand a tidbit or two, and confuse this partial knowledge with expertise.

    Thermodynamics involves just a few laws which are used to make statements about what is potentially possible and what is forbidden.

    It is well known that it is energetically possible for diamond to spontaneously change into the lower energy form called graphite. It is an “allowed” process, not a “forbidden” process.

    All “”allowed” (energetically favorable) processes do not indeed happen spontaneously. Diamonds, by millions of observations, do not decompose to graphite at any readily observed rate.

    The Rate of Reaction, is not a concept of classical thermodynamics at all. Most commonly it is covered under the topic of Kinetics, usually called Chemical Kinetics.

    You can look at the tables of contents and indices of dozens of books on thermodynamics and there is virtually no mention of chemical kinetics. Classical thermodynamics simply does not predict the rates of chemical reactions or phase changes. Kinetics addresses these concepts.

    There are, commonly accepted, four laws of thermodynamics (Zero, First, Second and Third Laws). If somebody doesn’t know all four laws of thermodynamics, I don’t bother to discuss anything they say about “thermodynamics”. If someone don’t know why there is a zeroth law, they are missing something of basic science.

    Because of the basic ignorance of the subject, there is great misrepresentation of the subject in dietary literature.

    The “idea” of 3500 Calories of food deficit resulting in one pound of weight loss is just one glaring example.

    I have never met a “Nutritionist” with or without degrees who knows the four laws of thermodynamics. Of course none of them actually know what is properly predicted (or not predicted) by classical thermodynamics.

    • avatar Zoë Harcombe says:

      Hopefully I’m the nutritionist exception knowing the zeroth to the third laws and how and why they came about:-) Probably why I totally agree that this whole subject is a great example of a little info is a dangerous thing. I remember the first time a dietician told me that the calorie theory was true because you can’t change the laws of the universe. Battle of wits, unarmed person and all that!

      • avatar Jim Buch says:

        Thermodynamics uses the term “spontaneous” in a different context than ordinary language. It does not mean rapidly or immediately. Spontaneous applause, for example, is usually immediate following some event. According to Professor Peter Atkins, in the book “Four Laws that Drive the Universe”, states the following (page 54).

        ” The word ‘spontaneous’ is another of those common words that has been captured by science and dressed in a more precise meaning. In themodynamics, spontaneous means not needing to be driven by doing work of some kind. Broadly speaking, ‘spontaneous’ is a synonym of ‘natural’. Unlike everyday language, spontaneous in thermodynamics has no connotation of speed: it does not mean fast. Spontaneous in thermodynamics refers to the tendency for a change to occur [not necessarily its actualization]……. Thermodynamics is silent on rates. ”

        The digestion of lactose (milk sugar) for most people is not only spontaneous, but it is actualized at a useful rate (by observation). Hidden within the reaction pathway for lactose digestion is the key activation of a chemical stage by the enzyme (organic catalyst) lactase. Without this enzyme (catalyst) lactose will not digest and the calories within this lactase will not be converted into energy by the body lacking this enzyme.

        Many Asians and American Indians, among others, lack this enzyme.

        Therefore, at least for lactose, a calorie is not a calorie. Whether or not the calories in ingested lactose are converted into “energy” depends on the presence of the catalyst (enzyme) lactase.

        Humans are not all Model T Fords, some are of other makes and models.

        The pseudo-theory that “a calorie is a calorie” expresses ignorance of the human biochemistry to which it is applied.

  8. avatar Tye says:

    I must say, there seems to be a lot of missed points here.

    First, the 3500 kcal/lb is ludicrous on any number of levels, and many good points have already been made, save for the most obvious one – just because X Calories of food (notwithstanding the fact that not all Calories are equal) are consumed, that does NOT at all mean that the body has to do something with that stored energy.

    Second, thermodynamics is NOT simply about movement of heat energy. It is the study of energy transfer in chemical and physical reactions. That includes reactions in which heat or motion energy might be converted to potential energy in chemical bonds. Digestion, storage, and use of the stored energy in food or from fat involves chemical reactions and the manipulation of chemical bonds to release and store energy.

    Third, and related to the first, it’s not simply a matter of stored energy in = energy the body has to do something with because different food types give the body different biological cues – they don’t just go into an unchanging furnace. Almost all foods can trigger biological adjustments throughout digestion (e.g. sugars and simple carbs upscaling insulin production from the moment they’re sensed in the mouth (or even before if the subject is anticipating) or gut, or fats slowing down digestion to ensure enough time for chemical processes to work correctly, or fats causing the release of specific digestion-aiding chemicals, etc). These triggers can cause the body to behave in very different ways regarding fat storage, metabolism slowing/speeding, osmotic balance, etc, etc.

    IMHO, the real problem is not whether or not thermodynamics has to do with weight, but whether 1) all incoming Calorie-equivalents of food are equal with regard to fat storage, 2) all Calories stored in bodyfat are equal no matter the circumstance of use, and 3) the rather loose interrelation between Calories and weight (of fat, muscle, or whatever) is EVER useful in the first place.

    • avatar Jim Buch says:

      You can write a lot of “possible reactions” that satisfy the first law of thermodynamics [energy], but that doesn’t mean that the “possible reactiion” you wrote WILL ACTUALLY HAPPEN.

      Among other things, the “possible reaction” must also satisfy the second law of thermodymanics [entropy].

      Even if both the first and second laws of thermodynamics are satisfied, that doesn’t mean that the “possible reaction” actually occurs at a practical rate. The classical thermodynamics subject is devoid of any concept of kinetics.

      For example, the traditional example of the thermodynamically allowed spontaneous decomposition of diamond to graphite (at room temperature and pressure) does not proceed at a readily seen rate. In addition, most biochemical reactions are thermodynamically allowed but will not actually occur without the appropriate enzymes being present to catalyze the kinetics. Enzymes can speed up biochemical reactions by well over a million times.

      Folks who lack the lactase enzyme cannot digest lactose and generally avoid drinking milk as a result.

      So, just because someone can write a reaction that says that a pound of fat is calorically equal (upon laboratory bomb calorimeter testins) to 3500 calories doesn’t mean that this results in a practical sense the loss of one pound of fat for each 3500 additional calories dissipated or expended somewhere or everywhere in a human body.

      This thinking shows that the writer knows some pieces of classical thermodynamics – yes. but does not actually represent proper application of the application of thermodynamics.

      However, a claim that 3500 additional calories of energy dissipation or utilization in the body results in 2 pounds of fat loss appears to be a violation of the first law of conservation of energy. That is that this 2 lb. for 3500 calories proposal is apparently a violation of the conservation of energy ( the same as the first law of thermodynamics).

  9. avatar Andy Greenhalgh says:

    appreciate this blog page Zoe, it’s got me thinking.

    I agree with the 3,500 calories being too wide an estimate to be relied on but I still think we can play with the numbers and see what happens on the scales where it matters. I try to lose weight by leaving myself a calorie deficit of 250 which in theory means I should lose 1/2 a week – I don’t. if after a few months I have lost more than I wanted I increase my calorie intake and so on until I lose a staedy 1/2 a week, I get to my goal weight then try to maintain it. The key is to weigh myself every week – playing with the numbers is harmless enough if I keep one eye on the scales.

    What I’m trying to say is that I agree, calorie counting is not scientific but weighing yourself every week is – if i’m playing with the numbers (3,500 calories = 1lb per week, 250 daily deficit etc) and I gradually lose weight where’s the harm?

    Surely a systematic approach (even if flawed scientifically) is better than just eating healthy and not counting any of the calories – surely you would just put weight on?

    Thanks Zoe.

    Andy

    • avatar Zoë Harcombe says:

      Hi Andy – I wrote a 134,000 word book mostly about this!

      Interestingly – this is what Keys did in the Minnesota Starvation Experiment. He did not adhere to or mention the 3,500 theory at any stage but tried instead to develop his own formula and he then resorted to your kind of trial and error. He would weigh the men each week and adjust their calorie intake down further if they weren’t losing as he wanted them to. The trouble is – at about the 6 month mark when calorie deficits seem to reverse for most people – he could no longer induce further weight loss for many of the men and some even started regaining at around 1,000 cals a day or lower and they were trying to steal food with hunger!

      I never subscribe to eating less – only ever eating better. I’ve written so much about what happens when people try to eat less and losing weight is not the only or even most likely outcome.

      The videos on here may help! http://www.theobesityepidemic.org/category/research/
      Best wishes – Zoe

  10. avatar Shannon Roscoe says:

    Hi Zoe the information you have presented is really fascinating. I myself have been on diets to lose weight and they all worked using the calories in calories out formula. For example I calculated my BMR then x using the Harris Benedict equation found myself to be needing 2700 calories to maintain weight. So i consumed 2000 calories a day and found myself to be losing about .7 pound a week exactly as expected. Later I did the reverse and the expected outcome was achieved, but with a 500 surplus. The doctor doing my dexa scan gave me the calories in and out formuala advice when going on a weight loss plan aswell. But if there is no literature so conclusively support the argument I don’t see how people are giving this advice. I myself have given people this advice as thought it was universally accepted, and becuase it worked for me! If there is no literature or formula to support weight loss what advice can we give dieters?

    • avatar Zoë Harcombe says:

      Hi Shannon – the advice I give on the calorie formula is don’t believe it – it simply does not hold. Never has; never will. I bet it only ‘worked’ approximately for you and in the very short term. Do it for a year and see if you lose 104lb in fat alone – more in water and lean tissue. There is no formula. I know that people want a formula – do X and this will happen – but there isn’t one and anyone who suggests otherwise is lying and being cruel with people’s hopes.

      The advice I give on weight loss is 1) eat real food 2) three times a day – stop grazing! and 3) – if (1) and (2) haven’t got you to your natural weight then manage carb intake carefully.

      Good use of the Harris Benedict equation though – not many people take care to know the deficit needed :-)
      Best wishes – Zoe

      • avatar Shannon Roscoe says:

        Ill never lose 100lbs of fat because im 76kgs. All im saying is I monitored my calorie intake and like predicted the the amount of weight(not fat)came off. I lost 6kgs of fat and 1kg of muscle!(dexa scan results)It wasn’t approximate it was pretty much exact(within .25kgs) All i’m trying to say is there is some merit to the theory, maybe not in extreme cases of obesity but for people in an acceptable body fat% ranges(I have no evidence to prove that statement it is just anecdotal), however the most important part is knowing how your body is responding to the food your consuming, not what your consuming, hence most people don’t understand how to apply to the calories in and out theory. Therefore it is so hard to prove.

  11. avatar jean says:

    My son eats ten times what we eat and he is still a string bean. This ‘theory’ of energy in and energy out does not work. He sits at under normal weight on the BMI and is six foot two inches tall. He eats at least five litres of ice-cream every two days, plus, for every meal he eats two, the second usually an hour after the first. Two breakfasts, two lunch two dinner, plus stuffs himself with chips (he is starving all the time), he will eat a whole chicken not just one piece. I’ve been in touch with dieticians regarding his weight and their advice is to bulk up his food with things like sustagen powder, add oil and fat to meals (more than he is eating), and he is STILL skinny. When I looked at what was in Sustagen, I wondered why dousing a boy in soy powder could be good. And he does NO exercise at all. He has always been like this, underweight. a theory is an idea. When it is proven then it becomes a fact. It seems the theory is being ‘sold’ like it is FACT. If it was fact, my son should be getting fatter as he has stopped growing but still eats enough for five people, every day.

  12. avatar Jerome Whitney says:

    There is a significant difference between total calorimeter calories in a food or substance and AVAILABLE calories. Then there is the factor of individual bodily function as to the percentage of available calories that can be assimilated.
    See: http://www.ars.usda.gov/is/AR/2013/sep13/calories0913.htm

  13. avatar Bill LaChenal (London) says:

    Splendid piece or inquiry into commonly touted official ‘science’!

    But sorry, the whole calorie thing is simplistic nonsense, not even worth a moment’s consideration.

    Calorific values are arrived at by nothing more complicated than burning food (or fat/flesh/bone etc), and measuring the heat produced.

    So there is this idea that putting on bodyweight depends solely on calories consumed, balanced against energy expended (E=mc²). Utter balderdash

    Consider at first thought: petroleum, coal, wood are generally known as splendid sources of heat when burnt.

    So – according to the patently lunatic calorie theory – if you are under-weight and each day eat just a medium-rare lump of coal with wood chips all washed down with a nice glass of kerosene (maybe include the paper plate), you should put on weight in no time.

    Perhaps I should conduct an RCT to be sure, but I’ll hazard a guess that the hypothesis is not going to fly. What in my young day we used to call “reductio ad absurdum”.

    The theory is palpable nonsense. Wake up now, you know it’s nonsense. You would have to be severely nutritionally deprived to even to begin to consider it has any merit whatsoever.

    Which is even before glancing at the role of, say, water.

    The point is that the calorie theory skips the essential point: that the quality and composition of foodstuffs is of prime importance, not its potential for generating heat (except perhaps as spurious argument).

  14. avatar Howard says:

    Hi Zoe,
    The whole problem is that certain sectors of the medical fraternity view human activity using a “furnace model” – i.e. energy in vs energy out. If there is a imbalance internally it must be turned into something in the body. A pound of fat internally has a calorific value of about 3500 cal, so then if there is a deficit of this amount the body needs to keep the energy equation constant so it will somehow burn a pound of fat or deposit it.
    The energy content of foods are rated according to how much heat they will give off when burnt.
    This completely ignores the fact that after eating certain foods (fats) a person will feel satiated and not want to eat anymore for a while, whereas other foods seem to induce a permanent feeding frenzy because they induce a cycling full/empty feeling (carbs).

  15. avatar Spencer says:

    Sorry if anyone else has already pointed this out, but the formula also fails in the other direction: people on hypercaloric/force-feeding diets and studies rarely gain one pound for every “extra” 3500 calories they eat. In fact, if not coming from a history of restricted eating, they often gain at a rate of less than half of what the formula says they “should” be. (For example: an account of a girl eating 5000 calories per day gaining at the rate of 50 pounds every six months, or 8 pounds per month, despite the fact that given her weight and daily energy expenditure, the formula would have her be gaining 18 pounds per month!)

    • avatar Zoë Harcombe says:

      Good point Spencer! The Vermont Prison Experiment and the Horizon prog – why are thin people not fat? And every documentary about morbidly obese people where we’re told they eat 20,000 cals a day – bedridden – and they’re not gaining 4-5lb every day!

      • avatar Nick C says:

        The only formula anyone needs to know is: energy in – energy out = change in weight. There is no need to quantify how many calories it takes to burn a 1lb of fat.

        The reason a huge person does not gain 4lbs a day eating 20,000cals is as follows:
        The amount of calories a person burns in a day is dependent on their weight and how many calories(energy) is required to “maintain” that weight. I weigh 180 there for my ‘caloric maintenance’ amount is X. If I eat X every day I do not gain or lose weight. If another person weighs 500, their maintenance calorie amount is XXX. Therefor they can eat more than me(XXX) and not gain any weight. The person will only gain or lose weight when they over or under consume calories. Your “healthy daily value” of calories depends on how much you weigh when you’re healthy.

        • avatar Zoë Harcombe says:

          Hi Nick – you’re making the mistake of relating energy to weight. Thermodynamics is about energy (the movement of heat to be precise). It says nothing about weight.
          Best wishes – Zoe

        • avatar Spencer says:

          Hi Nick–your assumptions re: the mechanics of weight gain (as Zoe pointed out below), aside, those differences in metabolic rate were accounted for in the calculations.

          The girl in question (I’d rather not link to the article as I know the circumstances of her weight gain will just cause unnecessary controversy) currently weighs 230 pounds and eats, on average, 5000 calories/day. Given her weight, and assuming she sleeps 8 hours a night and is sedentary the rest of the day, a formulaic metabolic calculator says she requires 3,111 cals/day to maintain her weight. This would mean she is eating approximately 1,900 “extra” cals/day, or 360,000 extra calories over the course of six months.

          According to the same formula which claims 3500 extra calories = 1 pound of fat gained, she should be gaining at a rate of about 100 pounds every six months, or about 17 pounds per month. However, she’s actually only gaining at a rate of 50 pounds every six months, or 8 pounds per month.

          Zoe: thanks for mentioning those studies! There are many others that corroborate your findings as well; this is just the first I could think of off the top of my head but it’s neat (old, but that shouldn’t mean it’s discounted–the sample size was several thousand people): http://www.bmj.com/content/1/6164/655

          “Blood sugar concentrations and indices of glucose tolerance correlated positively with the degree of adiposity but tended to be negatively correlated with total food energy intake and its component nutrients (total carbohydrate, sucrose, and fat). This inverse trend was largely accounted for by highly significant inverse correlations between food energy intake and adiposity, a relation found in both sexes and in all three population samples and which extended across the whole range of nutrient intake and BMI.”

  16. avatar FrankG says:

    Many Thanks Zoe :-)

    Couple of thoughts which have been touched on already:

    A major issue with CICO/ELMM is the focus on “weight”, whereas it seems to me that most who “diet” are more interested in shedding excess fat mass and probably gaining lean muscle mass along the way… neither of which are best served by measurement of “weight” alone.

    The second one for me is this idea of creating a calorie “deficit”… I think this belies the fact that what we put in our mouths and how much time we spend on an elliptical trainer, are only part of the overall picture. There is so much more going on metabolically, over which we have much less (if any) concious control.

    I find it funny to think of dietiacains who decry saturated animal fat as a killer while advocating calorie-restriction. Don’t they realise that their presciption is causing an high-fat “diet” for their patients… sarurated animal fat as in, human fat which is almost identical to lard?!?

    No, if you consider that E-In and E-Out have to include the body’s own stores, then I submit that there NEVER is a deficit, unless we are dead or dying.

    CICO is wrong-thinking and a far too simplstic approach to the subtle adaptations which have shaped our metabolism over millions of years. Litte surprise then that CICO doesn’t work.

  17. avatar Darin Spurlock RD says:

    Well, now you know Its because the theory of that formula has never been proven in any study. But this avoids the more important question which is, “what is a calorie, anyways?”

    A calorie is a measurement of ‘potential energy’ which is not the same thing as absorbable energy.

    Even the way calories are measured have flaws in the way we are using a bomb calorimeter. For one, there was never a consensus regarding the starting temperature of the water in the calorimeter, nor was the atmospheric pressure defined. Second, the calorimeter is measuring the potential energy In a closed system. We are not taking in the energy from food in a closed system. We are not a bomb calorimeter. And in fact this process, ignores laws in thermodynamics.

    Now many will state, that weight loss is all about the laws in thermodynamics. Because ‘Energy is neither created nor destroyed, it only changes forms.’ But that is a law in energy conservation, which is the foundation for the laws in thermodynamics, but not a law in thermodynamics itself which deals with energy transfer from one closed system to another. Of course, one of the laws of thermodynamics states that in order for energy to be transferred from one closed system to another closed system, energy must be lost in the process. This concept has profound impact on our understanding of nutritional intake.

    What’s more interesting to me than all of that, is why do we only use one law in physics to rationalize weight loss? There are many laws in physics that are blatantly being ignored.

    I’m speaking to a group of doctors regarding this very topic in about 14 days. I hope it goes well, and we can stop it with this calorie nonsense. (Fingers crossed)

    • avatar Zoë Harcombe says:

      Hi Darin – what a great comment. Please can you post your talk somewhere? We’re working on a follow up blog on exactly this kind of stuff – the errors that people make when they try to apply ‘the laws of the universe’ to dieting. We hadn’t gone into the what is a calorie/calorimeter errors – we go into the misapplication of law 1 (conservation), ignoring law 2 (entropy), non reversible processes and – our most important one – the laws are about energy, heat and movement – not weight. That’s where humans went wrong!
      Many thanks for this
      Best wishes – Zoe

  18. avatar Thomas Herbert says:

    Zoe,

    You are probably already aware of these, but for other readers if they are interested:

    Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. Thomas DM1, Martin CK, Lettieri S, Bredlau C, Kaiser K, Church T, Bouchard C, Heymsfield SB. Int J Obes (Lond). 2013 Dec;37(12):1611-3. [PMID:23628852] http://www.nature.com/ijo/journal/v37/n12/full/ijo201351a.html

    Pennigton Biomedical Research Center – Calculators: http://www.pbrc.edu/research-and-faculty/calculators/

    Quantification of the effect of energy imbalance on bodyweight.
    Hall KD1, Sacks G, Chandramohan D, Chow CC, Wang YC, Gortmaker SL, Swinburn BA. Lancet. 2011 Aug 27;378(9793):826-37. [PMID:21872751] http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(11)60812-X/fulltext

    The National Institute of Diabetes and Digestive and Kidney Diseases – Body Weight Simulator: http://www.niddk.nih.gov/research-funding/at-niddk/labs-branches/LBM/integrative-physiology-section/body-weight-simulator/Pages/body-weight-simulator.aspx

    • avatar Zoë Harcombe says:

      Many thanks Thomas – I hadn’t seen the simulator, but I’ve got the rest. They highlight another important factor about any formula – time. The first study looks at an average of 9 weeks and it still fails at every level. The results would have worsened as time went on. I keep coming back to – I’m supposed to get to 6lb in less than a year on a 1,000 cal deficit?! I plotted the actual results of the Franz 2007 review of 80 studies (26,000 people) against the calorie formula at 4 years and they’re out by a factor of up to 70 and that’s comparing weight with what should have been lost in fat alone.
      Best wishes – zoe

      • avatar Valerie says:

        If you were able to actually create a 1000-calorie deficit daily, well, yes, you would starve to death within a few months (no, of course, you would not survive long enough to reach a weight of 6 pounds). Creating the 1000-calorie deficit would become harder and harder as time goes by, but if you succeeded, yes, you would lose weight. You eventually would lose much more than 2 pound per week, as you would lose lean mass which contains much less energy than fat mass.

        What do YOU think would happen if you created a 1000-calorie deficit daily for a year?

        • avatar Zoë Harcombe says:

          I know what happens – I proved the formula wrong personally 30 years ago and have been fascinated by it since. Hence my finding your presumption that I didn’t try to find the answers for myself (plus some ill chosen words and general tone) rude and offensive.

          Benedict seems to have been the first to find out what happens with calorie deficit over weeks (Francis G. Benedict, Human Vitality and efficiency under prolonged restricted diet, (study 1917, published 1919).)

          Strang made an important contribution a decade later (James M. Strang and Frank A. Evans, “The Energy Exchange in Obesity”, Journal of Clinical Investigation, (1928).).

          Keys pretty much settled the debate in 1945-50 (Ancel Keys, The Biology of Human Starvation, (study 1944-45, report 1950).), which I blogged about here 4.5 years ago (http://www.zoeharcombe.com/2009/12/the-minnesota-starvation-experiment/).

          Then we have Stunkard A. and M. McLaren-Hume, “The results of treatment for obesity: a review of the literature and report of a series”, Archives of Internal Medicine, (1959). George A. Bray, “The Myth of Diet in the Management of Obesity”, The American Journal of Clinical Nutrition, (September 1970). Rudolph L. Leibel, Michael Rosenbaum and Jules Hirsch, “Changes in energy expenditure resulting from altered body weight”, The New England Journal of Medicine”, (1995) and a classic from more recent years Marion J. Franz, Jeffrey J. VanWormer, A. Lauren Crain, Jackie L. Boucher, Trina Histon, William Caplan, Jill Bowman, Nicolas Pronk. “Weight Loss Outcomes: A Systematic Review and Meta-Analysis of Weight Loss Clinical Trials with a Minimum 1-Year Follow-Up”, Journal of the American Dietetic Association, (2007).

          The latter recorded WEIGHT loss at a mean of 3-6kg at 48 months. According to the calorie theory, FAT loss alone should have been 188.8kg at this stage.

          Try it! You say you have weight to lose and you’ve tried low carb, which suggests you wouldn’t mind losing weight. Create a deficit of 1,000 calories a day for a year and let us know if you become the first person on the planet to ever adhere to the formula.

          • avatar Valerie says:

            The studies you link to did not create a 1000-calorie deficit. They lowered caloric intake by 1000 calories. This is a huge difference! I guess that is also what you mean when you say you “proved the formula wrong personally 30 years ago”. I guess you decreased you caloric intake and at some point you stopped losing weight despite your continued efforts. That’s what is supposed to happen. You reach a new caloric equilibrium at a lower weight, with a lower caloric intake (and lower caloric expenditure). You do not live in a perpetual state of energy deficit.

            Do you understand what I mean? That there is a huge difference between lowering your caloric intake vs creating a calorie deficit? The “calorie theory”, as you call it, is about calorie deficits. Now, I see in some of your quotes from governement website that some people oversimplify or misinterpret the “calorie theory”. Yet, every study I have seen where they actually create a calorie deficit (expenditure > intake) confirms pretty closely the idea that 3500 calories = 1 pound of fat.

          • avatar Emily H. says:

            Valerie writes that “The studies you link to did not create a 1000-calorie deficit. They lowered caloric intake by 1000 calories. This is a huge difference! …. You reach a new caloric equilibrium at a lower weight, with a lower caloric intake (and lower caloric expenditure).”

            But that is kind of the point of “debunking” the 3500 calorie argument, is it not? We’re frequently told to lower our calorie intake by nutrition/fitness experts who assume that doing so will NOT automatically lower our calorie expenditure. They make it sound like caloric expenditure is pretty much determined by your choice of physical activities (workouts, walking a lot, etc.) & not by homeostatic mechanisms you have no control over.

            If eating fewer calories does indeed _automatically_ result in burning fewer calories, then there is little point in cutting calories to lose weight. You’d just settle in at a new metabolism, & there’s no way to measure how many calories you’re burning daily, anyway.

            Yes, the studies Harcombe cites leave open the possibility that creating a “real” 1000-calorie deficit would result in the predicted weight loss. But since there’s no way for ordinary dieters to know when they are acheiving this, the advice is useless and misleading.

          • avatar Valerie says:

            Emily, I agree with your view that the advice to reduce caloric intake will not cure obesity. But Zoe goes much further than that in her post. She seems to go after everything: the caloric content of a pound of body fat, the biology of energy use/accumulation, the eat-less-move-more treatment of obesity, etc. I’m not sure if she understands where the correct facts end and where the errors begin, or if she is blindly attacking anything with the word “calorie” in it. Her post and her comments leave me wondering.

            If we go back to Zoe’s quotes in the blog post, well, most of them are not even wrong! The quotes from the BDA and the NHS may not be terribly useful, but they are not false. Why attack them? I think the science is correct there.

            The NOS quote is definitely wrong. That kind of statement does more harm than good, and I believe the public would be better served if it were corrected. But after losing so much credibility with the rest of her rant, I don’t see how Zoe could be taken seriously and help change the public discourse.

  19. avatar Dawn Hudson-Taylor says:

    I have started your eating plan adn I am on to Phase two. My husband and I have both lost a few kilos already and it is a satisfying way of eating. And not so hard to follow. Also I have just been diagnosed as having type 2 diabetes. Probably had it for years too, but nobody checked and I feel so well. Since starting the diet I have felt more energised thatn I have for ages. The doctor told me he woudl give me 3 months to lose 5 kilos and get my sugar and cholesterol down. I don’t have high blood pressure – in fact one nurse said it was as good as an 18 year old’s. I have tested my sugar a few times now adn it fluctuates a lot. Do you think 3 months will be long enough to bring it down? I am not yet on any medications and hope not to need them.

    • avatar Zoë Harcombe says:

      Hi Dawn – there is a general trend in the medical world of redefining normal as high. A normal distribution means that it is entirely normal that the normal distribution curve will represent the normal population.

      Here is a link (http://www.trialsjournal.com/content/6/1/5) with a couple of very interesting graphs – open up figure 1 and figure 2. Figure 1 is the higher number when you have your blood pressure reading (the 140 in 140/90 kind of thing). This shows that the normal blood pressure range for the general population is anywhere from 90 to 240 as the top number, with 130 being the most common reading and the average being around 140.

      Figure 2 is the lower number (the 90 in the 140/90) and this ranges from 50 to 130. The most common is around 85 and the average is around 90. So the true average blood pressure in the normal population is c. 140/90. You may be aware that 140/90 is the definition of high BP! Normal has become high and then everyone who is now deemed high shall be medicated, when they are in fact normal.

      The same has happened with cholesterol – where the true – pre-statination – average used to be around 7-8 mmol/l. You will now be told that your cholesterol is high if it is above 5. It is in fact well below average at 5.

      I share this because blood glucose is another area where normal has been redefined as high. Here’s another interesting graph (http://www.obesitymyths.com/myth8.2.htm) – this time American – so I’m not sure of your location but hopefully you can find an on line converter between mg/DL and mmol/l depending on where you are based. This one shows how much of the area above the true average has been redefined as high – no longer normal.

      So my first thought back would be – check that you really do have an issue and not just that you have become a statistic for the convenience and profit of drug companies. A healthy person is worth nothing – telling you that you are pre-diabetic makes you more valuable. Secondly – I think you are right to try to resist medication and especially if you don’t have a genuine blood glucose problem (which hopefully you can work out with the above). Metformin is the most common drug given to type 2 diabetics and I don’t have room to go into what it does here but it’s trying to ‘squeeze out’ any life left in your beta cells and what then? There are also weight gain issues with diabetes drugs (significant ones) and then you end up with a cyclical weight/diabetes/drug problem. It’s madness.

      I would be doing what you’re doing – trying real food, managed carb. I don’t know how long it will take for your blood sugars to become more stable and ‘normal’ – in the true normal range. They may be there already. I don’t think any doc would know this either – hence the sensible advice for you to come back after a time to check again. The less carbohydrate you consume, the better this is for blood glucose levels. Diabetes is the condition of being impaired in handling glucose/carbohydrate so why on earth are diabetics told to eat starch all day long? (http://www.drbriffa.com/2014/05/09/if-diabetes-uk-wants-to-help-diabetics-i-suggest-it-stops-recommending-a-diet-that-i-think-is-utterly-unsuitable-for-diabetics/) and (http://www.zoeharcombe.com/2012/05/diabetes-uk-low-carb-diets-%E2%80%93-what-is-the-official-advice-for-diabetics/)

      I hope this helps!
      Very best wishes – Zoe

      • avatar Hugh Mannity says:

        Weight also suffers from the “redefine normal as high” rule. The actuarial tables for height and weight were originally calculated by insurance companies for the purpose of estimating life insurance risk.

        Since the 1950s those tables have been redefined downwards at least twice. So it was possible to go to bed a normal weight and wake up in the morning 10lb overweight.

        That’s not to say that obesity doesn’t exist, nor that it’s not a problem. Just as high cholesterol exists and can be a problem for some people (those with familial hypercholesterolemia for example), obesity does exist and can be problematic. It’s more that not everyone classified as “obese” by either actuarial tables or BMI is actually unhealthily heavy (or fat, if you prefer).

        Weight is, like most other human measures, more or less a bell curve. There’s more than one basic body-type (remember the old “ectomorph, mesomorph, endomorph” categories? When did you last hear of them?) And some healthy people will be fatter, or thinner, than other healthy people of the same height.

        We, as a society, are bordering on a collective eating disorder here.

        • avatar Zoë Harcombe says:

          Good point Hugh!

        • avatar Catherine says:

          Well said, that man!!

        • avatar Jacqui says:

          Good point, Hugh!

          In addition, a) it matters where the excess weight is distributed (as in podgy thighs better than visceral deposits) and b) there are some ‘normal’ weight people who are less fit and less healthy than some who are a little overweight.

          I’m not saying the population isn’t getting fatter – they are, and worryingly so, but I like your point about the potential of a ‘collective eating disorder’ developing.

  20. avatar Catherine says:

    I think that the main point of the calorie matter is the fact that anyone deciding to reduce their intake by 500 calories per day to lose 1lb per week is going to be sadly disappointed. As Zoe has stated several times, if it were true, all of us serial slimmers would be dead before we’d lost the weight we need/want to lose! Our bodies clearly know nothing about mathematical formulae, and will respond as they see fit to a calorie deficit, and this response is different for everyone. I offer myself as an example. I joined a well-known weight loss organisation in May last year, purely to support my husband in his chosen method of weight loss (he wanted to lose weight for health reasons). At six months’ membership, I had lost a total of 24lbs. At one year’s membership, I had lost 24lbs. In the last six months, I have gone up and down the same four or five pounds. I ended my membership last week, mainly for financial reasons, but also because I’ve had enough of it. I am going to resume Zoe’s excellent “eat real food” programme, and I have no doubt that I will be able to at least maintain my 24lbs lost. I say that quality of calories is what counts, not the quantity.

  21. avatar David H says:

    Of _course_ the formula’s wrong. 1 lb is clearly approximately 9.77e12 kcal. (Dumb physics joke, for which I feel no shame.)

    More seriously, I have no problem using 3500 kcal as a zeroth order approximation for the amount of energy stored in 1 lb of adipose tissue. That respects that the number is a rough estimate in absence of any other information, yet it’s also a far cry from saying 3500 kcal = 1 lb weight loss.

    Also, from the DOM UK Committee quote: “… so to lose 1 lb of fat weight per week you would need an energy deficit of 7000kcals per week, or 500kcals a day.” I think that’s just a math error on their part, as the 500 kcal/day works out to 3500 kcal/week rather than 7000. It still doesn’t provide any support for the rule, though.

    That said, I’m not disagreeing with you at all. Mostly, I couldn’t pass up that joke.

  22. avatar Kenny says:

    Hi Zoe, thanks for bringing up this important topic again. Here’s a great article,

    Why is the 3500 kcal per pound weight loss rule wrong?
    KD Hall and CC Chow

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859816/

    Int J Obes (Lond). Author manuscript; available in PMC Dec 11, 2013.
    Published in final edited form as:
    Int J Obes (Lond). Dec 2013; 37(12): 10.1038/ijo.2013.112.
    Published online Jun 18, 2013. doi: 10.1038/ijo.2013.112

    We welcome the recent article by Thomas et al.1 criticizing the commonly used 3500 kcal per pound weight loss rule. This echoes our research showing that the 3500-kcal rule leads to overestimation of weight loss in individuals and populations.2,3 Despite our agreement with the spirit of the article, we believe it has the potential to generate confusion about exactly why the 3500-kcal rule is wrong.

    The most serious error of the 3500-kcal rule is its failure to account for dynamic changes in energy balance that occur during an intervention. Unfortunately, we feel that this error is obscured by the equation of Thomas et al.1 meant to represent the predictions of the 3500-kcal rule: W(t) = W0 + ΔEB × t/3500, where the change in energy balance, ΔEB, was defined as the difference between the rates of energy intake and expenditure. What the authors failed to stress was that they calculated ΔEB as the initial difference between the energy intake and expenditure rates and assumed it to be a static quantity. In reality, ΔEB is dynamic and, if accurately estimated over time, then the above equation provides a reasonable estimate of weight change.

    Mathematical models attempt to correct this deficiency by estimating the dynamic changes in ΔEB.4 Thomas et al.1 correctly demonstrated that the typical assumption of a static ΔEB leads to exaggerated weight loss predictions with no plateau. However, the static ΔEB assumption was not explicitly stated and the reader may be led to the erroneous conclusion that the deficiency of the 3500-kcal rule is the numerical value ‘3500’.

    Conservation of energy requires that the cumulative energy deficit (that is, the integral of ΔEB) equals the energy lost from the body. The 3500-kcal rule was motivated by calculating that a pound of adipose tissue stores approximately 3500 kcal.5 A more accurate accounting of body composition changes demonstrated that this value is appropriate for modest weight changes in overweight and obese people, but is an overestimate in others.6 However, using a ‘corrected’ numerical value for the energy content of lost tissue does not repair the 3500-kcal rule without also accounting for the ΔEB dynamics.

    • avatar Zoë Harcombe says:

      Hi Ken – many thanks for this – Kevin Hall has done some very interesting work in this area. I’ve got a few of his papers in my Endnotes. However, he’s still trying to find a formula and there isn’t one. When you look at the one study in this blog (the 12 people) sent by two different organizations, any possible formula is out by so much to make it absurd. The idea that I could cut back by 1,000 cals a day and weigh 6lb in a year’s time (actually 6lb in less than a year because that would be fat alone… actually be dead sooner than that anyway)… it’s just absurd. And yet publications (governments and magazines alike) still get away with perpetuating this nonsense “cut back by 500 cals a day and you will lose 1lb a week”. No you won’t!
      But I do like KH for his maths alone!
      Best wishes – Zoe

      • avatar Kenny says:

        Of course, you’re right, Zoe – there is no formula. I’m just glad that someone of Kevin Hall’s stature is explicitly attacking the 3500 kcal rule at all. The whole article is amusing to me because Hall is criticizing Thomas for criticizing the rule in the wrong way, yet they are both wrong! It’s all just so entrenched that it’s hard for them to let go, but at least acknowledging that weight loss is not a linear function of caloric deficit is a good thing, no?

  23. avatar Modesty says:

    Valerie, low carbing might not be for everyone but if you try low carb high fat (LCHF) and don’t be fat scared you might succeed, given that you manage to get through the transition period also called carb flu, when the body changes from burning carbs (and using glucose as main energy source) to fat burning and using fat as the main source. Eat egg, meat, fish and seafood in moderation, vegetables low in carbs and plenty of good fat like butter, coconut oil and olive oil.

    • avatar Valerie says:

      Hi Modesty,

      I am contemplating a ketogenic diet. I was not deliberately avoinding fat when I tried low-carb, but I did end up eating lots of protein. I know for sure that my hypertension completely disappears when I fast for a long time (21 [miserable] days of fasting a couple years ago reduced my blood pressure dramatically). I have had two difficulties when I briefly tried the ketogenic diet:

      1- Immune crash dow (I caught an ear infection, a cold and shingles whithin a week of starting the ketogenic diet the first time. Could be a coincidence, but seems improbable).

      2- Hunger (My hunger does not magically vanish. If anything, the very small, dense meals are less satisfying than higher carb fare. Could improve long term, I guess).

  24. avatar Ash Simmonds says:

    “Hi Valerie – you must be a dietician. You have that unmistakeable blend of arrogance, ignorance and closed mindedness.”

    Gold.

  25. avatar Andrew says:

    Valerie – do you realise that by conceding that energy expenditure decreases as weight is lost through reduction of calorie intake, you have also conceded that the “calories in, calories out” principle is nonsense? The principle rests on the assumption that “calories in” and “calories out” are independent variables. As you have acknowledged, this is not the case – they are dependent variables. Obviously cutting “calories in” is futile if by doing so you also cut “calories out”.

    Zoe of course is well aware of all this – she links to a post on the Minnesota Starvation Experiment on her home page.

    (Though Zoe I wonder if your response to Valerie might have been a bit more measured, in the interests of getting your message across).

    • avatar Zoë Harcombe says:

      Hi Andrew – it probably should have been, but then the use of words like silly and troll are not used by someone trying to start out in a positive way! Plus – as you kindly point out – the suggestion that all I needed to do was search pubmed was one rolled eyes too many. I wrote a 134,000 word book on obesity with 400 references – I didn’t just challenge the 3,500 theory on a whim!
      Best wishes – Zoe

  26. avatar Valerie says:

    Hi Zoe,

    Thanks for the charming reply.

    The reference I linked to was the first one that popped up on a simple Google search. I read the abstract, did some simple math (they give weight loss and its composition, and I roughly estimated the calorie deficit) and it come pretty darn close to 3500 calories per pound of fat lost.

    My point was that you didn’t seem to even try to find the answers yourself. It is unfortunate that the “calorie theory” got distorted into simplistic advice on the site you mention in your post. Yet, the theory has been verified in metabolic ward studies. 3500 calorie deficit produces pretty close to 1 pound fat loss. Here is another one that finds the same thing:
    http://www.ncbi.nlm.nih.gov/pubmed/15767618

    For the record, I am not a dietitian, I am just a fat person who tried the low-carb diet after reading Taubes. I got no benefit whatsoever from the low-carb diet, but my interest in nutrition science (or lack of it) remains.

    • avatar Andrew says:

      Valerie – the study you refer to here only lasted 2 weeks. In longer term studies, weight loss falls well short of that predicted by the calorie principle.

      The problem with trying to lose weight by creating a calorie deficit is that we lose muscle as well as fat and our metabolic rate goes down. When we start eating normally again, because of the lowered metabolic rate (and also because our eating tends to get out of control as the body responds to the end of semi-starvation) the weight goes back on (this time all as fat) plus more, so we end up fatter than we were before. As an alternative of course we can try an continue semi-starving ourselves for the rest of our lives, but few people are capable of that, and what a miserable existence anyway.

      But I suspect I’m not telling you anything you don’t already know.

      I’m sorry you have tried low-carb and found it unhelpful. However I think you started in the wrong place. Taubes is a great writer with brilliant insights, but I wouldn’t look to him for practical advice. If what you followed was the diet at the end of “Why We Get Fat” then I’m not surprised it didn’t work for you. 1 cup of this, and 2 cups of that, no more than 6 olives a day (why?), counting carbs gram by gram, artificial sweeteners that stimulate the insulin response and cause sugar cravings etc etc. And at 20g of carbs a day it is quite extreme – I certainly couldn’t have kept to it.

      Aiming for low carb is the wrong mindset – we should aim (as Zoe would say) to eat “real food”. Essentially this means eating what we evolved to eat – meat, fish, seafood, eggs, leafy plants, berries, etc. This necessarily results in a low-carb diet without us having to count anything. Consideration of carb content is only needed in order to assess whether a more recent addition to our diet is metabolically suitable – eg full fat yoghurt, butter, cream (yes); milk (not really); tomatoes (yes); potatoes (not really) – and even then no gram by gram counting is needed.

      For practical advice on diet I go not to Taubes but to the wonderful John Briffa. “Waist Disposal” is ostensibly for men, but equally applies to women; or alternatively there is “Escape the Diet Trap”. Following Dr Briffa, I have found, as have many others, that where food intake is concerned, focussing on “what” means that “how much” takes care of itself.

      • avatar Valerie says:

        Hi Andrew,

        When I tried the low-carb approach, I had already been eating (mostly) “real food” for many years. I swapped fruits, grains and legumes for meat, cheese and butter. My weight didn’t budge (if anything, I gained a few pounds), which was disappointing, but what surprised me the most was that even my hypertension didn’t improve (low-carb is supposed to lower blood pressure even without weight loss, on average at least).

        I totally agree with you that semi-starvation is miserable. I would even say it is unhealthy (especially if we include mental health in the picture). And indeed, it is extremely difficult to maintain a calorie *deficit* over long periods of time (hunger increases and energy expenditure decreases for many reasons). Still, in order to lose body fat, a calorie deficit needs to occur, and the 3500 calories per pound of fat is a pretty good approximation.

        I completely agree that it is false to say that you will lose 1 pound per week (indefinitely!) if you eat 500 fewer calories per day. That is a silly oversimplification. So, Zoe’s quote from the NOS is just plain wrong. But the quotes from the BDA and the NHS are mostly accurate. They may not be all that helpful, but they are not wrong. Zoe’s questions had easy answers (that she could find on her own), or they pointed easy mistakes (for which she could have suggested corrections). In any case, asking faux questions to government employees in charge of emails might prove their ignorance, but I fail to see how it is going to help anyone.

    • avatar Martin Levac says:

      Yes, the experiment found mass loss matched expected according to initial Ein-Eout deficit. However, in order to show this, they used a low-carbohydrate diet. As we know from other experiments with low-carb diets, mass loss is not equivalent across diets, in spite of equivalent Ein-Eout deficit across diets. For example, in the A-TO-Z experiment, the 4 diets produced different mass loss while having equivalent Ein-Eout deficit. Thus, if the Boden experiment was repeated with a Standard American Diet instead, we can expect it to fail to replicate the results that were achieved using a low-carbohydrate diet.

      • avatar Martin Levac says:

        In addition, the implication of the A-TO-Z experiment with regards to the Boden paper is that Boden must have tried his experiment several times – each time using different macro ratios – before he found the precise macro ratio that would produce the desired results. It’s highly unlikely that he stumbled onto the correct macro ratios by accident, the first time he performed the experiment, the only time he performed the experiment.

      • avatar Valerie says:

        Martin, the A-to-Z experiment was in free-living people. We can’t know for sure how much they ate. More importantly, we don’t know what happened to their calorie expenditure. It is very plausible that diet composition affects energy expenditure (and hunger) at least in some people. So, eating 500 fewer calories does not necessarily lead to a 500-calorie deficit.

        • avatar FrankG says:

          Thank-you Valerie for nicely summing up yet more reasons (as if we needed them) as to why basing a diet on calorie-counting is a fatally flawed approach :-P

          That was your intention… right?

          • avatar Valerie says:

            Calories count, but counting calories is not a solution to obesity.
            However, pretending that calories don’t count is even worse.

  27. avatar Jacqui says:

    Excellent follow-up, Zoe – keep at it!
    (I do keep saying this, and people nod along with me… and the next day they are saying, ‘Oo, I can’t have X with all those calories’… How to get the message across?!)

  28. avatar Tyrannocaster says:

    To Steven Kelly: “If you want to lose weight, eat less (and exercise more).” I can’t believe you said that on this blog. LOL! Are you sure you aren’t Marion Nestle?

  29. avatar Tee Dee says:

    Right on, Zoe. I’m with Tyrannocaster in that I admire the way you persistently try to get to the very bottom of things to find out their origins–especially from the sources you contacted (not harassed). They should know these things as we are the ones who also support their work. I would also like it if they just admitted there are many variables and that the 3,500 calorie ‘rule’ is an approximation at best, and it should always be noted as such, or gotten rid of altogether. Keep up the excellent work!

  30. avatar Ash Simmonds says:

    Yup, calorie counting is still an eating disorder.

    Take a look at this, the #1 calorie counting website tells me that 3 slices of bacon is somewhere between 81 and 641 calories:

    - https://twitter.com/AshSimmonds/status/474729310377365504

    Good luck CICO zealots!

  31. avatar Valerie says:

    It is rather sad that nobody had the references on hand. However, there is no real controversy. Metabolic ward studies have been done, and the calorie-deficit method does produce the expected weight loss. A simple search on Google Scholar turns up references right away. Here is one of them (I used “calorie deficit weight” as search words).
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC333231/

    Your examples are silly. The 500-calorie deficit has to be maintained for one pound of fat to be lost every week. The key word here is deficit. As you lose weight, your energy expenditure decreases. I am pretty sure you know that. And I am pretty sure you are able to find the metabolic ward studies yourself. Harassing government agencies might prove that the employees are ignorant (or that your emails have been flagged as trolling), but it does not prove that the energy conservation theory is shaky.

    • avatar Zoë Harcombe says:

      Hi Valerie – you must be a dietician. You have that unmistakeable blend of arrogance, ignorance and closed mindedness.

      You have sent one reference, which proves that in 6 subjects, with 3 different interventions, lasting just 10 days each, the weight and fat lost were different. They adhered to no formula, let alone the 3,500 calorie myth.

      Thank you for sending yet another study that proves my point, but the request at the end of the post remains the same – prove this formula or stop using it.
      Best wishes – Zoe

  32. avatar David Harley says:

    Try this as a source.

    Am J Clin Nutr September 1958 vol. 6 no. 5 542-546

    http://ajcn.nutrition.org/content/6/5/542.full.pdf+html

    • avatar Zoë Harcombe says:

      Hi David – got it thanks – it’s where the upper limit comes from – see my reply to Phil
      Best wishes – Zoe

  33. avatar James M says:

    Well, the point is good that its too simplistic to suggest you will lose weight by restricting a certain number of calories. And yes, they should stop repeating that suggestion to people if it has no basis. But on the other hand, its a more ‘digestible’ message than something like,
    “If you burn 3500 calories a day due to thermogenesis, muscle movement, and other bodily processes and you stay in a room that is 70f all the time and all other variables that we may or may not know about are equal, then reducing caloric intake by 500 calories a day should equal 1lb of body fat lost per week.”

    I mean, there must be some equation like,
    Weight change = Calories in – calories shat (poo burns yo!) – calories for heat – calories for exercise – calories for normal biological processes.

    I’m no expert so what else did I leave out?

    • avatar Zoë Harcombe says:

      Hi James – what you left out is how you flit between energy and weight interchangeably because you can’t. Thermodynamics (and most people misinterpret the first law and forget to account for the second) says NOTHING about weight. It’s about energy. More accurately, it’s about the movement of heat. Weight = weight. Calories = energy.
      Best wishes – Zoe

      • avatar Tom says:

        Actually you can “flit” between weight (mass) and energy…hence Einstein’s theory of relativity: E=MC^2 is the same as M=E/C^2

        • avatar Andy says:

          Hi Tom,
          If that is your belief, how would you explain the thermodynamics, or Einstein’s hypothesis (which was initially base on light energy), to a power station, where thousands of tons of mass (coal) are converted to weightless energy (electricity). Is this reversible (can the electricity be converted back to coal, or gas, or oil, or some other mass based energy source)? Can we simply ‘flit’ between mass and energy in this scenario? If so. How does it apply to the human body?

          • avatar Banzai Otis says:

            Wow.

            Professor Andy just poo-pooed mass-energy equivalence…
            …a key conclusion from the theory of special relativity…
            …possibly the most thoroughly tested and validated theory in existence…
            …tested by a century of the most brilliant minds on the planet.

            But what the hell does all that count for. Andy’s gut tells him he’s right. And Andy is obviously really smart and modest.

            So take that Tom! (and Einstien, and Bohr, and Plank, and Schrodinger, and Heisenburg, and Feynman, and…)

  34. avatar Michael B says:

    I really enjoyed this post. What’s kind of scary is that the calorie theory relies on complete ignorance of two facts that seem self-evident even to myself, with very little training in physiology or biology. 1) All calories are not created equal – for example, the body responds differently to a calorie of fat compared to a calorie of carbohydrate. 2) Body metabolism changes based on amount of food eaten.

    It’s interesting how so many of these theories are based on ignorance. I think here of Malcolm Kendrick’s articles on why it is impossible for a saturated fat to be converted into cholesterol.

    Yet another instance of “Don’t bother us with the facts. Our minds are made up!” Particularly when there are massive industries predicated on that ignorance (e.g., statin drugs, weight loss).

  35. avatar Steven Kelly says:

    Great that you’re pushing them to produce actual scientific evidence. I agree with fredt’s comment, though: If you want to lose weight, eat less (and exercise more); if you eat more than you need, you risk putting on weight. Anything more specific than that runs a serious risk of being too complicated, not applying to everyone or even most people, and being overturned by subsequent investigation.

    The mechanisms by which we lose or gain weight are not well understood at all. The media, those who make a living or a name for themselves on health issues, and even the scientists who let their research be simplified to the breaking point to get it in the news – all these are guilty of watering down the little we actually know with so much popularization and “expert advice” that nobody really believes anything they hear anymore.

  36. avatar PJ (RightNOW) says:

    If eating or not-eating 3500 calories equaled a pound of fat, I would weigh 1/4 what I do. I think the larger one is, the more the ‘calorie theory’ becomes ludicrously unrelated to whatever is going on.

    I once thought that I could so easily disprove that theory given the way my body works, but then I remembered that allegedly all fat people, without exception, lie about their food according to research. I remember seeing a ref on Dr. Sharma’s blog a few years ago to this study where all the overweight people — these are completely separate unrelated people mind you — over the course of weeks of the study, allegedly lied about what they ate, but the real kicker is, they allegedly all ate — and lied about — precisely the same number of calories every day! IMO this is nearly impossible to do with a bunch of separately living independent people even if you TRIED. It beggars belief that nobody even questions this.

    Allegedly the gut biome can make the calories absorbed or not absorbed vary up to 500 per day — while resistant elements make FFA’s in the gut. Why does this never get mentioned when talking about calories? They’re willing to make people obsess on 22 extra calories a day but their own body internally could make things vary by 25 times that?

    PJ

  37. avatar PhilT says:

    While I don’t hold with the folk theory of obesity that 500 cals a day will turn into 1 pound a week of weight loss / gain, I do think the average or typical energy equivalent of lost adiposity has a basis in science from Wishnofsky in 1958 with references to Strang et al from 1928 http://ajcn.nutrition.org/content/6/5/542.full.pdf+html

    • avatar Zoë Harcombe says:

      Hi Phil – Many thanks for this. I reference both of these in my obesity book:
      “James Strang and Frank Evans (1928) observed that obese patients get hungry on calorie restriction diets and their energy expenditure ‘diminishes proportionately much more than the weight’.” (James M. Strang and Frank A. Evans, “The Energy Exchange in Obesity”, Journal of Clinical Investigation, (1928).)

      The Wishnofsky is where the upper 3,750 cal limit comes from. He refers (in the article you nicely reference) in turn to Bozenraad: “It was shown by Bozenraad that the average fat content of human adipose tissue taken from various parts of the bodies of well nourished subjects is 87 per cent. One pound (454 grams) of human adipose tissue, therefore, contains 395 grams of fat. The caloric value of one gram of animal fat is 9.5; consequently, the caloric equivalent of one pound of human adipose tissue may be considered to be about 3,750 cal.”

      Wishnofsky took that as fact but the 1911 Bozenraad article gave the range of fat content in adipose tissue as anything from 72-87% (Bozenraad, Deutsche Archives Internal Medicine, (1911).), which is what I used in establishing a range. The range could be even wider with other references, but the point had been made.

      Best wishes – Zoe
      p.s. the earliest source of the theory I found was Lulu Hunt Peters 1918 (Lulu Hunt Peters, Diet and Health (with key to the calories), published by Chicago The Reilly and Lee Company, (1918).) but this offers no proof – just states as fact “Five hundred Calories equal approximately 2 ounces of fat. Two ounces per day would be about 4 pounds per month, or 48 pounds per year. Cutting out 1000 Calories per day would equal a reduction of approximately 8 pounds per month, or 96 pounds per year.” Really?!

  38. avatar fredt says:

    But to prove it, they would need to understand the variation in biological conversion of carbohydrates, excess protein and fat into energy, and to the variation in the forms and concentration of storage. We each have personal values of the Atwater factors. Atwater through out 1/2 his data because it was scattered so bad, it must be wrong. They would also need to account for hysteresis, which makes the math real interesting to work with.

    Do you really expect administration to deal with the complexities that they do not understand or with reality?

    All this make the maths near useless for anything beyond direction of change. Eat less than you are currently eating and your metabolism slow and starts to conserve, body temperature drops, energy drops, motivation reduces, and you may lose weight or not depending on the body. Reverse for the opposite. But what do I know?

  39. avatar Tyrannocaster says:

    Zoe, this is simply awesome; I really admire your tenacity with this thing. It would almost be funny it the issue weren’t so serious. It really is an emperor with no clothes clothes on.

    Please keep it up! Thank you so much.

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