The standard retort of mainstream nutritionist on low carb diets is that they just force you too eat less calories and a calorie is a calorie no matter what. Interesting study's from post WW2 on how to feed starving Europe says different. Subjects on high carb 1500 calorie per day diets starved and had health issues both mental and physical while those on the same calories but low carb diets did just fine. "Over the twenty-four week starvation part of the study, the subjects not only lost a considerable percentage of their body weights, but suffered a number of problems as well. As the time wore on the men thought ceaselessly about food, they became lethargic, they were cold all the time, they became depressed, they developed bleeding disorders, their ankles became edematous, and some developed more serious psychological disorders." Both studies provided between 1500 and 1600 kcal per day, but with huge differences in outcome. In the Keys semi-starvation study (high-carb, low-fat) the subjects starved and obsessed on food constantly. In the Yudkin study (low-carb, high-fat), the subjects, who had no restriction on the amount of food they ate, volitionally consumed the same number of calories that the semi-starvation group did, yet reported that they had an increases feeling of well-being. Instead of lethargy and depression reported by the Keys subjects on their low-fat, high-carb 1570 calories, those on the same number of low-carb, high-fat calories experienced decreased lassitude. "Both groups of subjects were consuming the same number of calories, but one group starved while the other did just fine. One group had to be locked down to ensure they didnt eat more than their alloted 1570 calories; the other group voluntarily dropped their intake to 1560 calories and felt great. What was the difference? Subjects in both groups ate the same number of calories." http://fourhourworkweek.com/2008/02/25/the-science-of-fat-loss-why-a-calorie-isnt-always-a-calorie/
