The recent publication of the results of the A TO Z trial of four weight-loss “diets” made headlines around the world: “ATKINS DIET TOPS”. The group on the Atkins diet lost about 10 pounds, a few more pounds than the others, after one year of “dieting”.
Did anyone, including the paper’s reviewers, actually look at the numbers behind this conclusion? Table 1 shows the baseline parameters.
Note that the average BMI was about 32. One is considered to be obese above a BMI of 30. So most were obese. Note also the weights. About 85 kg. Now look at the results in Table 2 (below). Remember that these numbers are derived by SELF REPORTING of food consumption and exercise. The subject could tell the investigators anything. There was no check on what they said. They were paid, so the subjects had an incentive to the investigators what the subjects thought the investigators wanted to hear. The subjects claimed to be eating about 1900 kcal/day at the outset of the trial. Any adult who eats only 1900 kcal/day is UNLIKELY TO GET OBESE in the first place. During the trial they claimed to be eating only about 1500 kcal/day. So even if they hadn’t increased exercise they should have had a deficit of 400 kcal/day, 2800 kcal/wk. One pound of fat is about 3500 kcal. So, if we are to believe what they reported, they should have lost at least 3 pounds per month or 36 pounds per year. But even the Atkins group only lost 10 pounds. It gets worse. They reported total energy expenditure of about 35 kcal/kg/day. Multiply by their weight and you get about 3000 kcal/day. But they claimed to be eating only 1500 kcal/day. So they should have lost two to three pounds per week, at least 100 pounds per year. Also note that total calorie intake remained about the same in all groups in spite or a wide range of percentages of protein, fat and carbohydrate and by the end of the trial these percentages tended towards the same fraction in all groups. The First Law of Thermodynamics says energy cannot be created or destroyed. Any study of energy flows that cannot first show that energy is conserved should never be published. The methods employed by the study are fatally flawed. No conclusion can be drawn from this data. Many interpretations are possible. So, if all groups ate the same REPORTED calories on the average and burnt the same REPORTED calories on average, why did the Atkins group lose a little more weight? Maybe the Atkins group did a little more exercise. Who knows? They were lying about everything. Or, maybe, for some reason those presumably following the Atkins diet were slightly less proficient liars as the others.
That obese people lie about food intake was proven beyond doubt by a study using doubly-labeled water to measure true energy expenditure. About 65% of these subjects were overweight or obese. They claimed to be eating only about 1500 kcal/day but were burning 2500. So, they should have had a deficit of 1000 kcal/day and be losing weight dramatically but their weights were stable. Ergo they were “misreporting”, a euphemism for lying.
The real cause of obesity is food addiction. Like alcoholics food addicts will deny they consume too much and/or exercise too little. See my photo essay on the topic. Which diet is this lady on?