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Reference books


The Women's Health Initiative Dietary Modification Trial

(References: “The Obesity Code”: Dr. Jason Fung, 2016)

(In the U.S.)The National Institutes of Health recruited almost 50,000 post-menopausal women for the most massive, expensive, ambitious and awesome dietary study ever done. Published in 2006, this randomized controlled trial was called the Women's Health Initiative Dietary Modification Trial. This trial is arguably the most important dietary study ever done.

Approximately one-third of these women received a series of eighteen education sessions, group activities, targeted message campaigns and personalized feedback over one year. Their dietary intervention was to reduce dietary fat, which was cut down to 20 percent of daily calories. They also increased their vegetable and fruit intake to five servings per day and grains to six servings.
They were encouraged to increase exercise. The control group was instructed to eat as they normally did. Those in this group were provided with a copy of the Dietary Guidelines for Americans, but otherwise received little help. The trial aimed to confirm the cardiovascular health and weight-reduction benefits of the low-fat diet.

The average weight of participants at the beginning of the study was 169 pounds (76.8 kilograms). The starting average body mass index was 29.1, putting participants in the overweight category (body mass index of 25 to 29.9), but bordering on obese (body mass index greater than 30). They were followed for 7.5 years to see if the doctor-recommended diet reduced obesity, heart disease and cancer as much as expected.

The group that received dietary counseling succeeded. Daily calories dropped from 1788 to 1446 a dayーa reduction of 342 calories per day for over seven years. Fat as a percentage of calories decreased from 38.8 percent to 29.8 percent, and carbohydrates increased from 44.5 percent to 52.7 percent. The women increased their daily physical activity by 14 percent. The control group continued to eat the same higher-calorie and higher-fat diet to which they were accustomed.

The results were telling. The“Eat Less, Move More”group started out terrifically, averaging more than 4 pounds (1.8 kilograms) of weight loss over the first year. By the second year, the weight started to be regained, and by the end of the study, there was no significant difference between the two groups.

Did these women perhaps replace some of their fat with muscle? Unfortunately, the average waist circumference increased approximately 0.39 inches (0.6 centimeters), and the average waist-to-hip ratio increased from 0.82 to 0.83 inches (2.1 centimeters), which indicates these women were actually fatter than before. Weight loss over 7.5 years of the Eat Less, Move More strategy was not even one single kilogram (2.2 pounds).

This study was only the latest in an unbroken string of failed experiments. Caloric reduction as the primary means of weight loss has disappointed repeatedly.(*snip*)

Many people tell me, “I don't understand. I eat less. I exercise more. But I can't seem to lose any weight.” I understand perfectly-because this advice has been proven to fail.

Do caloric-reduction diets work? No.


(Overeating Experiments: Unexpected Results)

THE HYPOTHESIS THAT eating too much causes obesity is easily testable. You simply take a group of volunteers, deliberately overfeed them and watch what happens. If the hypothesis is true, the result should be obesity.

Luckily for us, such experiments have already been done. Dr. Ethan Sims performed the most famous of these studies in the late 1960s.(*snip*)

Could he make humans deliberately gain weight? This question, so deceptively simple, had never before been experimentally answered. After all, we already thought we knew the answer. Of course overfeeding would lead to obesity.
But does it really? Sims recruited lean college students at the nearby University of Vermont and encouraged them to eat whatever they wanted to gain weight. But despite what both he and the students had expected, the students could not become obese.(*snip*)

Dr. Sims changed course. Perhaps the difficulty here was that the students were increasing their exercise and therefore burning off the weight, which might explain their failure to gain weight. So the next step was to overfeed, but limit physical activity so that it remained constant. For this experiment, he recruited convicts at the Vermont State Prison. Attendants were present at every meal to verify that the caloriesー4000 per dayーwere eaten. Physical activity was strictly controlled

A funny thing happened. The prisoners' weight initially rose, but then stabilized. Though at first they'd been happy to increase their caloric intake, as their weight started to increase, they found it more and more difficult to overeat, and some dropped out of the study.(*snip)

After the experiment ended, body weight quickly and effortlessly returned to normal. Most of the participants did not retain any of the weight they gained.