The low-carb vs low-fat study
On September 2nd 2014 a story broke in the field of diet and nutrition, but it barely made it across the pond. The New York Times headline was “A call for a low carb diet that embraces fat.” The Huffington Post covered the story, but didn’t devote a whole article to it. Instead they combined the findings of this study with another to report “What can we really learn from that low-fat vs. low-carb study?”
The BBC ignored it. The Mail did an on-line only piece “Time to throw out the bread! A low-carb diet IS the most effective way to lose weight – and it cuts the risk of heart disease, too.” Great headline, but you wouldn’t have come across the article by chance. I had to do a very specific search on the mail site to see if they had covered it. Similarly the Guardian had an on-line story “Low-Carbohydrate Diet Protects Against Heart Disease Study Shows.”
This is the link to the original article “Effects of low-carbohydrate and low-fat diets.” Dr Michael Eades has very kindly dropped it in his box for you to be able to see the full article.
Start, as usual, with any conflicts of interest. The study was funded by the National Institutes of Health, which is very interesting in itself. It’s the first study I’ve seen funded by a public body to review the effect of low-carb diets, let alone as compared to low-fat diets – the latter typifying public health advice. There is a full conflict of interest form, covering all authors involved in the study here. It is unusually and refreshingly completely void of any conflicts whatsoever. Oh to find a drug or food item study so genuinely independent.
The study was simple in design and meticulous in execution. Many of the medical site reviews of the study detailed and/or complimented the care that had been taken to make the trial as controlled as possible.
The study involved 148 men and women without cardiovascular disease or diabetes. The men and women were aged 22 to 75 years and had a BMI of between 30 and 45, so that they had sufficient weight to lose over the study period. The participants were recruited from the general public through open adverts. This generated more response from females than males, resulting in 89% of the subjects being female. The study was undertaken in New Orleans, Louisiana. 51% of the participants were black, 45% were white and the remainder were Asian and Hispanic.
73 of the participants were randomly allocated to the low-fat diet and 75 were randomly allocated to the low-carb diet. Table 1 in the paper shows the baseline characteristics of the participants. This is where we can check that the randomisation ‘has worked’ and we are equally like to have similar numbers of females in each diet group, similar numbers of different ethnic origins, similar starting weights and so on. The low-fat group were a couple of years older than the low-carb group and they were 1.6kg heavier on average (i.e. more weight to lose), but, Table 1 overall is reassuring that the groups started off from a very similar baseline.
The study noted that there have been very few attempts to study low-carbohydrate diets and none had ticked two important criteria of 1) actually being a low-carb diet and 2) studying a diverse population. The Gary Foster (2003) study did compare an actual low-carb diet (Atkins) to a low-fat (government advice) diet, but this did not involve a diverse/carefully randomised population. This study, covered in the BBC Horizon programme about The Atkins Diet, concluded that Atkins was better for weight loss and cholesterol measures. The usual attempt to study a ‘low-carb’ diet has involved carb intake in the 100-200g range. That’s a high-carb diet to the low-carb world!
This was different. The low-carb diet group target was less than 40g of carbohydrate a day. The low-fat diet group target was less than 30% of daily energy intake from total fat and less than 7% from saturated fat – model government advice therefore. I emphasised the word target because the discussions on-line about the study didn’t pick up the actual intake reported in the paper.
Table 2 reported the actual intakes of carbohydrate and fat for the two groups:
The low-carb group were supposed to consume <40g carb per day. They did in fact consume, on average: 97g carbohydrate/day at 3 months; 93g/day at 6 months and 127g/day at 12 months. The low-carb group thus substantially missed their targets.
The low-fat group, in contrast, did hit their total fat targets (they recorded saturated fat intake of between 8-9% during the study). They were supposed to consume less than 30% of their daily intake from fat and they achieved this: 27.5% at 3 months; 27.9% at 6 months and 29.8% at 12 months.
The researchers reported that 5 people dropped out of the low-fat group and 5 people dropped out of the low-carb group after 3 months. By the end of the study (at 12 months), 13 people in total had dropped out of the low-fat group and 15 had dropped out of the low-carb group. That was an 18% drop out in the low-fat group and a 20% drop out in the low-carb group. That’s a reasonably low drop out rate for a diet study and a number dropped out due to life stressors and/or pregnancy – understandable with a largely female group 22 years old and above.
The results fell into two main areas: weight and what the researchers called “cardiovascular risk factors.” One of these I value (weight), the other I don’t (cardiovascular risk factors – apart from to wave at people who do value it).
Weight: To quote verbatim from the study: “Weight loss was greater in the low-carbohydrate group than in the low-fat group at 3, 6, and 12 months.”
The main results are worth capturing in a little table (this is an extract from Table 3 in the paper).
|Body weight (kg):||Low-fat diet||Low-carb diet|
|– at 3 mths||-2.6kg||-5.7kg|
|– at 6 mths||-2.3||-5.6|
|– at 12 mths||-1.8||-5.3|
|Lean mass (%):|
|– at 3 mths||+0.4%||+1.60%|
|– at 6 mths||+0.2||+1.5|
|– at 12 mths||-0.4||+1.3|
|Fat mass (%):|
|– at 3 mths||-0.3%||-1.10%|
|– at 6 mths||-0.1||-1.1|
|– at 12 mths||+0.3||-1.2|
This tells us many interesting things:
1) As the researchers reported, weight loss was greater in the low-carb group at 3, 6 and 12 months – at least double at all three checks. This was despite the fact that the low-fat group achieved their dietary target of <30% fat and the low-carb group did not achieve their target of <40g carb a day – not even close.
2) Lean mass increased more, at every checkpoint, with the low-carb group.
3) Fat mass decreased more, at every checkpoint, with the low-carb group.
4) Even with the low-carb group missing the 40g/day target quite substantially, this group continued to have good results for weight, lean mass and fat mass at 12 months. Notice the low-fat group displaying the classic 6 month turnaround – with regain following. This was clearly illustrated by Marion Franz’s 2007 review of 80 studies involving 26,455 people. The classic graph from this study can be seen here. By 12 months, the low-fat group had regained 50% of the weight loss at 3 months and started to decrease lean mass and increase fat mass.
5) Perhaps most interesting of all – this study disproves the calorie theory (not that any study has ever proven the calorie theory – every study proves it wrong). The low-fat group were consuming, on average, 2,034 calories at base line and the low-carb group were consuming 1,998 on average. At 3 months, these averages had dropped to 1,418 and 1,258. At 6 months, these averages were 1,481 and 1,324. At 12 months, these averages were 1,527 and 1,448.
I’ve calculated what the 3,500 calorie theory says each group should have lost and it works out as follows:
– The low-fat group should have been 7.3 kilograms (multiply by 2.2 for an approximate conversion to pounds) lower at 3 months; 13.9 kg lower at 6 months and 25.9 kg lower at 12 months. They were, in fact, 1.8 kg lower at 12 months.
– The low-carb group should have been 8.8 kilograms lower at 3 months; 16.8 kg lower at 6 months and 29.8 kg lower at 12 months. They were, in fact, 5.3 kg lower at 12 months.
Remember that the calorie theorists say that low-carb diets only work because people eat less. Both groups did eat fewer calories, but the calorie theory was as ridiculously inaccurate as it always is.
The saddest finding for me, working in the field of obesity, was how little both groups lost, on average, over the course of a year with heavily supported and well monitored conditions. There was no mention of real or processed food in the study, so continuance of processed food in both groups may have hindered weight loss. I would also have loved to see the results for a group that actually achieved the 40g/day carbohydrate intake target, as this could have been impressive. As I find, and so do many others in the world of real food/managed carb, results can be substantially better than 5 kilograms a year.
Cardiovascular risk factors: I will report these rather than discuss them because, as people who know me will know, I have no time whatsoever for the notion that cholesterol is a risk factor in anything. It requires one to assume that the body makes cholesterol to kill the host – quite possibly the most absurd assumption that one can hold. Notwithstanding this, as most of the medical world is obsessed with total cholesterol and the lipoproteins LDL and HDL (while thinking that these are bad and good cholesterol and not lipoproteins ha ha), here are the results from the cholesterol jury:
At 6 months (comparing the period in which the low-carb group were at least below 100g/day):
– The low-fat group had higher total cholesterol, the low-carb group had lower total cholesterol.
– The low-fat group had higher LDL, the low-carb group had lower LDL.
– The low-fat group had lower HDL at 3 months and no change at 6 months, the low-carb group had higher HDL at both checkpoints.
– The low-fat group had higher triglycerides at 3 months and virtually no change at 6 months, the low-carb group had lower triglycerides at both checkpoints.
The only good thing about all this is that people who believe the diet-heart hypothesis say that low carb (by definition higher fat) diets raise cholesterol, LDL, triglycerides etc and NONE of this was found to hold true.
Perhaps the biggest story of all, however, was that the UK largely ignored this. Let not the evidence get in the way of public health advice eh?!
66 thoughts on “The low-carb vs low-fat study”
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Hi!Thanks for the comprehensive review, just an issue here, that – for me- demerit and otherwise unbiased study.
This is not actually low fat, that it is “lower” of what the government recommends us to eat doesn’t mean it is low (let’s not forget that following the food pyramid is a terrible idea). Low is about 10-15%, this is way too much fat to see any good performance.
So, in summary: “low fat” diet was still high fat (you can get to this conclusion, as many have, when comparing the % of fat ancestral communities eats or ate, I can expand on this but for the sake of this already too-long comment I won’t rn. and It is too high compared to the low-fat diets studies that have been successful treating modern diseases. And most important: is not low-fat compared to the standard american diet (right now supposedly it is at 34%) so they basically told people: hey, you can eat as you (or the standard american) eats. Especially because they didn’t ask for calory restriction. And we know the standard american diet is not working and is causing Heart-disease and obesity. So ofc it would fail. I’m actually surprised they managed to lower their weight at all. If anyone needs citations of my claims ask! I can give you the links if you want to know more. But the point that this does not make a case for HCLF vs HFLC.
Just checking I haven’t misread your comment or the above article but doesn’t it say:
“…they recorded saturated fat intake of between 8-9% during the study). They were supposed to consume less than 30% of their daily intake from fat and they achieved this: 27.5% at 3 months; 27.9% at 6 months and 29.8% at 12 months.”
So they actually had 8-9% and asked the participants to reduce their intake to below 30%. They wernn’t told to eat 30% they were told to reduce BY 70%.
8-9% is below the 10-15% you mentioned right?
Or am I missing the point here?
There was a program on recently comparing world wide diets and which are the healthiest http://www.channel4.com/programmes/the-worlds-best-diet/videos/all/the-worlds-best-diet-clip-1/3652004866001. They went to various countries where the populations are considered very healthy and have low morbidity and mortality: South Korea, Sicily, Iceland etc. The only thing that correlated between these different diets was the lack of processed foods. In every other respect e.g. how much veg, how much fat, how much wholegrain, how much meat, fish etc they differed markedly. The conclusion of the program makers was simply that eating natural foods grown/raised locally was the key to staying healthy. Processing kills food. Processing by definition is anti-life because by making sure the microbes can’t consume it you automatically ensure the microbes in our guts cannot consume this dead food. So how can we gain any nutrients if our gut biome is unable to break it down? Sugar of course is a preservative and therefore a killer.
How sensible! If only we could all unite that real food is the answer – the only nutrition debate would need to be – what should that real food be. Sadly, with global dietitian organisations sponsored by fake food, we can’t even agree on common sense.
Many thanks for sharing this
Best wishes – Zoe
Im amazed you answer posts. My BMI is about 25 and I do some cycling. I lost about 15lbs on LCHF, then I bumped into Dr McDougall posts that say go back to vegan that LCHF is a fad and ultimately a death sentence. Im a boomer and nagged by the thought that forty years of science about fat and cardio was “wrong.” What to do.
I don’t answer them all by any means! Some catch my eye :-)
Here’s my most recent conference presentation with my view on what to eat – the plants vs animals is the only debate – but there’s a clear answer: https://www.youtube.com/watch?v=wdznfiWvGq0&feature=youtu.be&a
Best wishes – Zoe
This is ridicules… a lb of fat is a lb of fat not 1 lb of fat = 87%fat. Otherwise it wasn’t a lb of fat to begin with. So lets get this strait right now, 1 gram of fat is 9 cals and 1 lb is about 454 grams. So 454 x 9 = 4,086 calories. End of discussion. The fact the someone would try to tell you that a lb of material is really a fraction of a lb of that material is just plain irritating. I wouldn’t take advice from someone so inept.
How low-fat is low-fat? %
In this study low-fat was <30% daily energy from fat and <7% daily energy from saturated fat - it's in the abstract of the paper
Best wishes - Zoe
I have been comparing the information and references given in other blogs here too. I am wondering if Zoe can please explain the contradictions in other studies that appear, equally informative websites on the subject of weight loss. The three I have picked out that contradict most opinions and studies on here are these.
http://ajcn.nutrition.org/content/32/8/1703.long A landmark study from 1979 according to another blog showing the benefits of starch based diets.
The AJCN (1979?!) is about 16 overweight men who went on a low cal diet for 8 weeks, which included bread, and they lost weight. To be precise half the men had regular bread and lost an avg of 6.25kg in 8 weeks and the other half had low cal bread and lost an avg of 8.77kg in 8 weeks. The low cal bread men ate 375 fewer cals per day than the normal bread men. So what? We know that cal deficit diets achieve short term weight loss (invariably then regained and often more). I’m not sure what the point of this is – aside from the fact that the second author works for the Continental Baking Company!?
McDougall declares himself as a low-fat vegan so beliefs will override independent evaluation of evidence. He seems to be attacking the Siri-Tarano study rather than putting evidence for something else?
Try this is you want a comprehensive listing of low fat vs low carb beyond the Bazzano study: http://smashthefat.com/science/
Best wishes – Zoe
There are lots of vegans about on you tube into high carb low fat eating. Whats the best study showing that high carb vs low fat is the wrong approach for obesity
Sorry, I meant to say HighCarbLowfatvegan vs Highfatlowcarb diet
Are you debating vegan vs non vegan or HCLF vs LCHF? Don’t confuse the two. Both healthy Vegans and Paleo tend to avoid processed food, which gives health benefits for both groups.
On HCLF vs LCHF there’s not one – it’s more the case that you’ll struggle to find one the other way round. I’ve already given you this link: with 25 (http://smashthefat.com/science/)
Here are 17 isolcaloric studies (some will overlap with Sam’s 25) https://www.zoeharcombe.com/2014/08/weight-loss-correlates-with-low-carb-not-low-calorie/
The blog post that you commented on has the most recent and one of the best I’ve seen. Not sure what row you’re having but you need to have it – no more of my valuable time :-)
Best wishes – Zoe
If there are few studies comparing High Carb low fat vs High Fat low carb how have we now changed to the wrong advice (LCHF).
Dr Mcdougall is not necessarily a vegan though.
As you are so diametrically opposed it would be great to see a public debate somewhere.
Newport or Sunny California?.
Zoe, in your book “Stop counting cal….” you say that triglycerides are too big to get out of the fatcells.
Why can you find them in my blood?
I am 77 and lost 7 kg on THD, went from size 42 to (ideal) 38 !
It’s unhelpful terminology (as people like Taubes and Kendrick have noted).
You don’t actually have triglycerides in your blood stream directly. Fat and water (lipids and blood) don’t mix, which is where lipoproteins come in – they carry triglycerides AND cholesterol AND phospholipids AND protein around the blood to do vital work. You probably mean you have VLDL in your blood stream – Very Low Density Lipoproteins – which are the Lipoproteins with the highest concentration of triglycerides and hence they are typically called triglyceride. This is not to be confused with (but it is all the time) triglyceride = body fat = 3 fats joined by glycerol. That’s the thing that can’t get in (or out) of fat cells as a structure. The single fatty acids cycle in and out of fat cells and then get locked in with a ‘backbone’ of glycerol when we eat carbs/get glucose & insulin and facilitate fat storage
Hope this helps!
Best wishes – Zoe
It was interesting reading this article, I am biased towards high carbs/low fat because myself, my mother and my father have each lost around 80lbs a pieces by a vegan diet with little oils and fats, and lots of brown rice, beans, fruit and veggies. Since the loss of much of my excess weight, after I gain some again, I never seem able to lose any if I am eating nuts, avocados and good oils, it has seemed I have always have to give up these loves, if I want to lose some pounds. I know that my own experience, families and others I’ve known who have lost lots of weight by switching to a low-fat diet is merely anecdotal evidence, but it makes it hard to know what I think of such studies as the one you shared here, since they fly in the face of my own experience. To be honest, I am wanting it to be true, fats make food taste SO good, Tahini with cooked Kale is heavenly, especially with walnuts sprinkled on, a coconut oil adds so much flavor.
Can anyone tell me where to find the low-carb diet of 40mg/day that these participants were on? I’d like to see the actual diet they followed.
Hi Ellen – the original journal article is in the links just under the first sub heading “The study”. The paper doesn’t detail a prescribed diet – just that the low carb group were instructed to have 40g of carb max a day – which they didn’t achieve.
Best wishes – Zoe
as a recent recipient of coronary bypass surgery, I was much saddened to read the Heart Foundation recommendations on diet. They appear to be living in stasis. I did my best to persuade the rehabilitation nurse to buy Kendrick’s book. I don’t think I left her smelling of roses!
Hi Roger – I did chuckle when I read that, but it’s not really funny is it? Well done you for trying.
Best wishes – Zoe
Why not buy the book for him/her as a thank you. Sometimes you have to bring the horse to water and throw them in!
Great post and web site Zoe, I just discovered your work.
Another study that found low carb outperforming low fat was the Standford ATOZ: http://www.ncbi.nlm.nih.gov/pubmed/17341711. There was slippage from targets in both diets here, not just the low carb. The lead researcher was Christopher Gardner, a Stanford professor who happens to be a vegetarian (albeit an open minded one). You can watch his entertaining presentation of the study here http://www.youtube.com/watch?v=eREuZEdMAVo
I have been a happy low carb convert for over a year now. I am in good health and not very carb sensitive so I do allow relatively more carbs than most LCHF dieters. I am 192cm, 90kg, consume on average 3000kcal per day and my macro-nutrient ratio is 60/20/20 (fat/prot/carb), meaning I eat about 150g of carbs per day. This may sound like a lot, but I think it’s better to look at macro-nutrient ratios rather than grams consumed given differences in weight among individuals.
Hi Mike – You’re right to do whatever works for you. I just eat real food and the macronutrients are what they are – I don’t even know! :-)
Best wishes – Zoe
p.s. many thanks for the study
Can anyone explain why Diabetes UK and the medical profession generally are STILL not on side?
Jolly good question! I did hear once from an informed source that Diabetes UK do know that their advice is wrong but don’t know how to come out and say “oops”. Meanwhile people are being harmed…
Some are trying their best (http://www.sciencedirect.com/science/article/pii/S0899900714003323)
Good to see your other post that you’re here so many years after you may not have been!
Best wishes – Zoe
Thanks for your reply. (In my other post of course I meant to say low carb not low cal) I should have added that my daily insulin has gone from 48 to 18. Wahey!
It is well established in biochemistry that gluconeogenesis can produce the needed carbohydrate for the brain from amino acids. Not all lipids can be synthesized, and so can be supplemented in the diet. So, on a high protein diet with a small amount of lipid and carbohydrates, one can achieve significant weight loss provided that enough protein is supplied. Vitamins and minerals need to be added as well. This is a very difficult diet to maintain because of lack of tastes acquired over the years. It is also very important to shift the muscles from carbohydrate utilization to fat utilization. This is easily accomplished by lowering the carbohydrate intake. This has the added benefit of lowering the type II likelihood.
Great post Zoe ! I would loved to have seen the comparative Lp(a) levels for both groups !
I do these routinely on all my patients who require risk assessment.
Hi there – that’s the one Dr Malcolm Kendrick also rates – two great minds :-)
Thanks for the great overview Zoe. I first heard about this study via a video by Discovery News which inspired me to compile other videos discussing low-fat vs low-carb studies. Would love to get any recommendations on other videos (unfortunately most of my friends and family can’t be bothered to read the actual studies). Thanks! http://www.chinabiohacker.com/blog/low-fat-vs-low-carb-diet-whats-healthier-video
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In the book “Big Fat Surprise”, by Nina Teicholz, she writes about another study where they looked at the results of 3 different diets: a low fat diet, a low carb diet, and the Mediterranean diet. In that study, the people on the low carbohydrate diet got stellar results, and not only lost more weight, but also improved their CHD risk factors more than the other 2 diets. Interestingly enough, the media praised the Mediterranean diet, which performed (not surprisingly!) better than the low fat diet, but they were oddly silent about the benefits of the low carbohydrate diet, even though it got the best results of all. Unfortunately I don’t remember the name of the study, as I loaned the book to someone, so I don’t have it here to look it up. But this seems to be a common theme!
Hi Lisa – if you ever get the book back it’s p213. Ref “Weight loss with a low-carbohydrate, Mediterranean or low-fat diet.” NEJM. (2008).
Check this too for 17 more: https://www.zoeharcombe.com/2014/08/weight-loss-correlates-with-low-carb-not-low-calorie/
Best wishes – Zoe
Oh yeah, right! By the way, I also read your book (“The Obesity Epidemic”), but don’t have it here to refer to because I loaned that one out too- (this is the 2nd person I’ve loaned it to; your book is making the rounds!) I like to give people these things to read, because I think this information needs to be spread around.
Can someone please tell me how to get to 70% fat, 20% protein and 5% carbs?
I imagine most people are hesitant to give advice over the internet. I can’t say how to do that, but I can say how I would give it a try.
I find that ~2000 kcal/day is my saddle point for not feeling too hungry (where I might be tempted to cheat on carb-laden foods), yet not feeling like I’m overeating, so I’ll use that as an example here. For 2000 kcal, that’d be about 100 kcal of carbs, 400 kcal of protein, and 1500 kcal of fat. That also provides the right amount of protein for me.
I’d first fill out the carbs with high-nutrient veggies, using a place like nutritiondata.self.com to check numbers and adjust quantities. Spinach, kale, asparagus, avocado, etc. Any fruits and most dairy products would also be added here, though fruit would be very sparing or absent, given such a restrictive carb load. (I would count carbs by subtracting fat calories and protein calories (i.e. 4* protein grams) from the total calories. That skirts around the non-absorbed carbs like fiber.)
From there, I’d fill out protein using animal products. Meats, eggs, organ meats (I love liver!), and non-carby dairy like some hard cheeses and butter. These are all effectively zero-carb, so they won’t screw up the carb balance.
After that, I’d balance out the fat using heavy cream, olive oil, etc. Once that list is made, I would check to make sure I’m not missing any vital nutrients. If it checks out, I can then figure out how to portion it out through the day. I would do that several times so I could figure out a variety of day-plans for food.
There are probably better ways of doing it, but that’s how I would approach it. Hope that helps.
My low carb doctor-prescribed diet usually runs 40 – 50 carbs daily. It IS hard, but totally worth it. My doc told me that my triglycerides and cholesterol would automatically lower on this diet. My cholesterol went up 10 points by 6 months into the diet (to 267), triglycerides went from 386 to 149, back up again to 243. My, cholesterol ratio, however, went from terrible to decent. All in all, a good thing for me. My knees stopped hurting, heartburn gone, quit PPIs. I’ve read that cholesterol going up is in fact normal, so the results of this study were surprising.
At present, HF diets are generally advantageous compared to LF diets in pretty much any aspect or metric you could pick.
Contrast that with – I would argue – good evidence that a long long time ago (in Paleo LaLaLand times), both a HF & LF diet could sustain normal health in humans. Normal health from back then, would equate to approximately excellent health nowadays, moi je dis! This does not tell us whether or not they were equally good – far from it. I think there is a stronger argument to be made for HF diets, even back then.
So why is it so much easier to be healthful on a ‘real foods’ HF diet nowadays that on a LF one nowadays? What are those environmental variables relevant to this modern susceptibility?
People on low carb diets do eat less, but it is because they don’t have hunger or cravings.
You need to work hard to banish carbs from your kitchen. That is the only way to achieve under 40g/d. For me, the key was to fill the cabinets and fridge with delicious no-carb real foods and have NO foods with even a few carbs within easy reach so if you want to snack, it will be an egg, lunchmeat with mayo, cheese, but no bread, or similar. Unsweetened drinks of choice (teas). Make it easier to consume 100g of fat than 10g of carbs. And eat during carb withdrawl.
My doctor put me on a low carb diet, and I am usually coming in at around 40 or 50 carbs a day. I was only a few pounds overweight at 56 years old, dropped those few pounds. She told me my cholesterol would come down, and so would triglycerides. My cholesterol went up to 267 , about 10 points. My triglycerides more than halved (386 to 149), but then jumped back up to 240. My ratios were awful, but now are good.
Why do these low-carb studies always descend into farce? Why do they allow the carbs to creep so high? At least it wasn’t calorie restricted like a of lot other low-carb fails. We’ll never know how good this trial could have been.
Although total cholesterol is completely meaningless, HDL/Trig ratio is an excellent indicator of LDL quality (glycation/oxidation), so I do think it’s very positive for heart disease risk. However, as far as I’m concerned, lowering LDL is a bad thing as there are hundreds of scientific papers, studies and trials showing that high LDL is associated with a longer, disease-free life, and quite the opposite for low LDL.
It would have been interesting if all the participants had been given a C-Reactive protein test for inflammation at the beginning and end of the study. I have no doubt that the low-carb diet would have won by a mile.
Interesting! That’s the test that my cardio-physiologist professor rave about!
That’s an excellent point. Also, was blood pressure and blood glucose levels measured, which are also very relevant to cardiovascular risk? Sorry, I haven’t read the paper in it’s full detail, yet.
C-reactive protein levels were taken: at baseline, 3 mo, 6 mo, and 12 mo and listed in a table of “mean predicted differences”. I understand neither the numbers nor “mean predicted differences”, so interpretation would be helpful to me.
Top find Greta! (probably not your real name ;-))
I hope that Terry spots this too.
C-reactive protein (CRP) rises in response to inflammation. This is a marker that people should worry about for heart disease. Whether you see inflammation as a cause or result of harm (or both), evidence for it is a concern. A rise therefore is not good news. A fall could be good news.
– The baseline CRP was 46.7 nmol/L in both the low fat and the low carb groups (Table 1).
– CRP at 3/6/12 months for the low-fat diet group was an average of 5.7/6.7 and 8.6 nmol/L HIGHER respectively.
– CRP at 3/6/12 months for the low-carb diet group was an average of 4.8/4.8 and 6.7 nmol/L LOWER respectively.
The paper reported “At 12 months, participants in the low-carbohydrate group had significantly greater decreases in CRP level than those in the low-fat group (mean difference in change at 12 months, -15.2 nmol/L.”
The numbers on CRP get even more interesting in the Appendix Tables 1 and 2. The differences among whites were much, much smaller than the differences among blacks (where the low-carb diet just embarrasses the low-fat diet at 12 months).
And then there’s this quote:
“Two previous studies that examined CRP levels found no difference between the diets (19,29); however, both had relatively small sample sizes and may have been underpowered.”
Given the huge error bars on CRP, I get the feeling that the diet/CRP relationship is going to be tricky to pin down.
hs-CRP is intersting and I can’t see where it has been properly studied. Our labs in Australia have different normal values and I have found them to be useless BUT looking let me give you some examples. Healthy young adults with normal homocysteine and HIGH NORMAL B12 and Folate and low triglycerides and high HDL have hs-CRPs around 1 or less than 1 (NML= 1 to 10) Those with values heading in the reverse direction but still ‘normal’ are in the 2 to 5 range. Useful test but forget the so-called normal ranges.
An interesting post on this strange brilliantly bizarre study, but how can you conclude the calorie – weight loss disparity is because the calorie theory is wrong? There is probably no need to look much beyond the data reporting as it is often incorrect, and, very likely, the big part of the reason for the disparity. And data errors are far more likely than that the calorie theory is wrong, a theory which, as far as I know, has never been shown to be in error. Of course, we are all awaiting NuSi’s metabolic ward studies with bated breath.
On the other hand, it is with certainty that your views on cholesterol are correct. “It requires one to assume that the body makes cholesterol to kill the host – quite possibly the most absurd assumption that one can hold.” Yep.
Greta it can be helpful in understanding the calorie theory to do the math (not often done, unfortunately). Imagine a 12 stone 20 year old man who decides to add a handful of nuts a day to his existing diet (very easy to do). A handful of nuts is around 60g or so – 400 calories. An extra 400 calories a day would mean an extra 146,000 calories a year, which divided by 3500 means a weight gain of 42 pounds (3 stone) in a year. Looking into the future, this handful of nuts each day would result in the man weighing 132 stone by the time he was 60. If he decided to add 2 handfuls a day to his diet (again, very easily done) he would weigh 252 stone at age 60 (253 stone if you take account of leap years).
This may seem a bit frightening, but it’s nothing compared to the plight of the 12 stone 20 year old man who already eats a handful of nuts a day but then decides to give them up. In 2 years’ time he would weigh only 6 stone, and in 4 years’ time he would have completely disappeared.
Like Zoe, I’m not convinced that the science behind this is entirely robust.
Go Andrew! I use me as an example – I’d be 6lb in a year’s time with a 1,000 cal a day deficit. Actually – as the cal myth applies to fat alone – there’d be more on top in terms of water/lean tissue, so I’d be minus quite a few pounds. Yes – is really is that absurd!
Best wishes – Zoe
“Perhaps one thing the study “proves” is just how difficult a very low-carb diet is for people to follow. 40 grams a day is pretty low. I wouldn’t be surprised if after a few days people just gave it up as unreachable”
This low carb lark is one tough gig. but I can take it.
Over six years on and luvin it, am I tough or what ?
Kind regards Eddie
I follow a diet with half that amount of carbs! Ye, the food selection is extremely limited, but so is my tolerance for some food items–I have multiple food allergies, and the Paleo diet is what fit the bill at the time. Then, I stopped losing weight, and began the Atkins Induction regimen, and still stalled, so I went down to keto.
Keto dieting (high fat, low carb, and low protein) plus dog-walking has netted me a 10 lb. weight loss in a month. I’m still losing.
I wish I could handle 40 carbs, but I simply cannot.
Ten lbs. per month is 100 lbs in ten months, right? That’s great, and all I would care about. I’ve lost 50 in almost four months, easing into it at around 60 grams carbs per day. Maybe the weight was falling off because I had SUCH a sugar-heavy diet that 60 grams (but zero sugar) was still a drastic drop? Or because everything I ate was “real” food? I don’t know, maybe both. Anyway I realized I didn’t really need the extra carbs and dropped them to 20-25 grams, figuring if it was too hard I could always add them back. As long as I could lose 10 lbs. per month I’d be satisfied, because at my age I need a little time to tone as much as possible or I’ll end up looking like a crepe-y Sharpei dog. I need to losing about 100 lbs. total – that’s alot of potentially saggy skin left over! The point I want to make is I have no problem at all staying off the carbs, because as predicted, I have absolutely no cravings or need for snacks. I think you’ll find that it will get easier after the first month, Wenchypoo; just ease into it the way you are and relax. And if it turns out you can’t handle 40 carbs but you’re still losing weight, who cares? Ten lbs. per month is awesome! The hardest part for me is finding meat with enough fat. The fattest country in the world sells the leanest meat!
I’m new to this site, and just starting reading the articles a couple of days ago. I come from Gary Taubes’ books, and his blog in which he praises Zoe; he’s trying to wake up America the way Zoe is trying to wake up the UK. This is a lovely site – the articles are great, and the comments are so civil. Nice meeting you all!
Oops, that was a poor way to phrase it, and I hope I didn’t offend anyone. “He’s trying to wake up America…”, etc. sounds a bit insulting to the people of both our countries. I should have said they’re trying to inform people that we’ve been sold a bill of goods and we must start to look at it more critically.
Hello perchancetodream – you’ve been very lovely – not offensive at all. That’s exactly what GT is trying to do and a growing number of others.
There’s a conference in SA next Feb gathering such thinkers together if you’re interested http://www.lowcarbhighfatexperts.com/schedule.html
Best wishes – Zoe
A personal testament to low carb weight loss -I’ve steadily decreased my carb in-take from 150g/day down to less than 40g/day since May 1. I’ve removed all sugar, wheat and processed foods from my diet. I started May 1 at 260lbs and weighed this weekend (09/07/14) at 200.5 lbs.
I am almost 50 years old male 6 feet 1 1/2 inches non-smoker and had blood work done last May. Next follow-up is the end of October.
I continue to eat REAL foods with 70%+ fats; 20%+ protein and 5%+ carbohydrates daily.
That’s a good point Jeff – here were the macro nutrient ratios for the low-carb group (Table 2):
At 3 months 29/26/43 carb/protein/fat
At 6 mths 28/26/43 carb/protein/fat – virtually the same
At 12 mths – 34/24/41
Certainly not the typical LCHF!
Best wishes – Zoe
Perhaps one thing the study “proves” is just how difficult a very low-carb diet is for people to follow. 40 grams a day is pretty low. I wouldn’t be surprised if after a few days people just gave it up as unreachable. They may have had better luck with a slightly higher goal, such an the 72 grams per day from “Life Without Bread.” Much more attainable.
Great post as always Zoe. As you said in a tweet today, imagine what a <40 carb per day diet can do. For countless type two diabetics it means normal non diabetic blood glucose numbers, much improved lipid ratios, very often zero diabetes medications, and very often weight reduced to healthy levels.
Increasingly we are seeing small but highly relevant trials and studies backing up claims we have made for years. Low carb works and keeps on working, for the over weight or type two diabetic, nothing else comes even close. Whole fresh food, home cooked is the answer, there is no get out of jail free card, hoping drugs will be our salvation is delusional.
Kind regards Eddie
“The study noted that there have been very few attempts to study low-carbohydrate diets and none had ticked two important criteria of 1) actually being a low-carb diet and 2) studying a diverse population.”
Errr… this study arguably fails the first and unarguably fails the second. I’m puzzled why you aren’t more critical. You’re normally all over this kind of stuff like stink on shit.
For what it’s worth, the study certainly *attempted* a true low-carb diet (<40 g/day) and did in fact have a diverse population according to their criteria (i.e. significant black population). I wouldn't mind a more diverse study either, but this is definitely a step in the right direction. Maybe they will get funding for a study of more than 150 people, and we can have better diversity.
From the article (and bless Dr. Eades for making it available!), this is the relevant prose. I'm still working through the rest, but it's a well-written article, no matter the conclusions.
"Few randomized, controlled trials thus far have examined the effects of carbohydrate restriction on CVD risk factors in a diverse population with a significant proportion of black persons. The few that have either did not assess a typical low-carbohydrate diet or included severely obese participants, most of whom had type 2 diabetes or the metabolic syndrome (4–6). Hence, we conducted a randomized, parallel-group trial to examine the effects of a 12-month low-carbohydrate diet compared with a low-fat diet (7–9) on body weight and CVD risk factors in a diverse population with a substantial proportion of black persons with no clinical comorbid conditions."