Thursday, January 23, 2014

Intermittent fasting: A better way to lose weight?

Before she deprived people of food, Dr. Krista Varady deprived mice. ... She would let them eat only a quarter of their normal diet on one day, then give them access to as much food as they wanted the next. ...

The days rolled by sequentially for the mice: fast, feast, fast, feast, fast, feast. ... Even on the days that the mice had access to unlimited food, they only ate about 25 percent more than average. They did not eat enough to compensate for the fasting days. So, over time, they lost weight. ...

She developed a protocol for humans based on her mouse experiments, and enrolled her first study subjects in 2008. She was surprised to find that, like mice, when people are given only 25 percent of their caloric needs on a fasting day, they do not eat 175 percent the following day. They actually only eat slightly more—115 percent or so. That means by the end of the week, they’ve eaten a lot less than they typically would, and they only felt deprived for 3.5 days. Another surprise: 80 to 90 percent of people were able to stick to the plan. ...

She is currently conducting an NIH-funded research trial in which people are doing six months of every-other-day dieting as compared to six months of every-day calorie restriction. At the end of a typical week, both groups eat about the same number of calories. "We're actually seeing," though, she said, "that the people in the every-other-day group are losing more weight—about five to seven pounds more—because they're just able to stick to it longer."

"And they like it more. They like that they're always able to look forward to the next day when they can eat whatever they want. They are able to feel normal sometimes." ...

She says the first ten days are "pretty difficult," but after that, people seem to get used to it.