Chapter 7 – Is the calorie formula true?

Evidence on weight loss from obesity journals

Benedict (1917) is believed to be the first to look at weight lost under calorie restriction.[90] He put 12 young men on diets of approximately 1,400-2,100 calories a day with the goal of lowering their body weight by 10% in one month. Their diets were then adjusted to maintain the lower weight for another two months. The men reported hunger, extreme cold and their energy expenditure dropped so dramatically that, if they consumed more than 2,100 calories a day (a third less than they had been eating) they put on weight. The men then overate and regained all the weight lost in less than two weeks. Within another three weeks they had gained, on average, eight pounds more.

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".[91]

As we saw in Chapter Four, the Keys’ (1944) Minnesota Starvation experiment is the most comprehensive study ever undertaken and the best documented evidence for the futility of calorie controlled diets.[92] Even after the definitive Keys’ study, researchers continued to study the effect of low calorie diets on obesity.

Having reviewed the literature from the first half of the twentieth century and having done their own study Stunkard and McLaren-Hume (1959) concluded "Most obese persons will not stay in treatment for obesity. Of those who stay in treatment, most will not lose weight, and of those who do lose weight, most will regain it.”[93] Stunkard and McLaren-Hume’s own statistical study showed that only 12% of obese patients lost 20 pounds, despite having stones to lose, only one person in 100 lost 40 pounds and, two years later, only 2% of patients had maintained a 20 pound weight loss. This is where the often quoted “98% of diets fail” derives from.

By 1970, the outcomes of such experiments were so well known that George Bray entitled his journal article “The myth of diet in the management of obesity.”[94] Bray referred to the Stunkard and McLaren-Hume study, amongst a number of other studies, and reached the logical conclusion: “If there was an effective diet, there would be no need for the continuous introduction of new diets: the ‘Grapefruit diet,’ the ‘Drinking Man’s diet,’ ‘the “Air Force diet,’ the ‘Mayo diet,’ the ‘Quick Weight Loss diet,’ and so on. It seems obvious from the number of diets that have been made available and are continuing to appear, none of them provides the answer to obesity.” Bray concluded, “Unfortunately, for the obese patient each new diet produces its temporary weight loss, but this is usually followed by a relapse, with weight returning to the same or higher levels.”