'Metabolic Advantage' Advantageous Only in Selling Books

Atkins claimed that the key to the so-called “calorie fallacy” was that the missing calories were explained by the excretion of ketones. Dieters in ketosis, he argued, urinate and breathe out so many calories in the form of ketones that “weight will be lost even when the calories taken in far exceed the calories expended.” He claimed dieters could “sneak” calories out of the body unused.[106]

The “Atkins Physician Council” also claims that one’s body expends more energy burning fat and thus “You wouldn’t have to increase your exercise at all because your body would be working harder, so that you could literally sit in your armchair and lose weight.”[107] As the Secretary of the AMA’s Council on Food and Nutrition tried to make clear, “The whole [Atkins] diet is so replete with errors woven together that it makes the regimen sound mysterious and magical.”[108]

These claims sounded so far-fetched that as part of an investigative documentary, the BBC paid obesity researchers to design an experiment to test it. So researchers took two identical twins and put one on the Atkins Diet for a while, the other on a high carbohydrate diet and locked them both in sealed chambers to measure exactly where the calories were going. Did the twin on the Atkins Diet have any sort of metabolic “advantage” by burning fat and protein as his source of fuel? Was he literally flushing more calories down the toilet? Of course not. “We found no difference whatsoever,” the researcher said.[109]

As the evidently “subnormal intellects” at the AMA concluded, “No scientific evidence exists to suggest that the low carbohydrate ketogenic diet has a metabolic advantage over more conventional diets for weight reduction.”[110] The only comprehensive systematic review ever done of low carb diets found that the carbohydrate content of the diet seemed in no way correlated with weight loss.[111] The truth seems to be that nothing matters more than calories when it comes to weight loss.[112] According to the director of nutrition at the Center for Science in the Public Interest, “This whole ketosis thing is just a gimmick to make people think there’s something to blame for weight gain and some magic solution to take it off. That’s the beginning and end of it.”[489]

But what about all the scientific studies Dr. Atkins cited in his book to back up his claims? Although his first book had essentially no citations, by the final edition he listed over 300.[113] Reviewing all of the studies on low carb diets, researchers concluded, “The studies by Atkins to support his contentions were of limited duration, conducted on a small number of people, lacked adequate controls and used ill-defined diets.”[114] Most importantly, though, some of the very studies he cites actually refute exactly what he’s claiming. And he accused the AMA of being “intellectually dishonest.”[115]

Of the few studies that did back up his claims, some had seriously questionable validity[116] and researchers could not replicate the findings of the rest.[117-134] One review of studies that have defended Atkins claims concluded, “It turns out that when these data are critically analyzed they are often found to be in error, and it’s therefore impossible to accept the validity of the conclusions derived by the authors from such erroneous data.”[135]

People lost weight on low carb diets the way everybody loses weight on any diet–by eating fewer calories.[136]