ST. LOUIS - Does periodic fasting offer greater value than counting calories daily? Researchers at Washington University in St. Louis hope to find out.
The research will look at whether limited fasting for a few days a week is easier than limiting food intake on a daily basis. They also want to learn if fasting helps with weight loss and slows aging.
The fasting is not absolute. Dr. Luigi Fontana says to aim for 500 calories on a fasting day, while eating normally the rest of the week.
Some animal studies have shown that intermittent fasting has the same effects on weight loss as chronic caloric restriction - defined by Fontana as reducing caloric intake by 15 to 25 percent daily.
Researchers also want to see if intermittent fasting has life-extending qualities that help prevent Type 2 diabetes, heart disease and Alzheimer's.
About 40 participants in the study are either overweight or slightly obese. Half of those studied will fast intermittently for a year, while the rest eat regularly for six months then begin intermittent fasting for the last six.
Some are already seeing results in their weight. Poonam Bhandari, a senior scientist at Washington University, has lost 10 pounds since January and her body mass index has improved.
Bhandari, 52, was instructed to begin by fasting three days a week. Her weight dropped so rapidly - about 2 pounds per week - that researchers reduced her fast to two days.
On fasting days, Bhandari has tea for breakfast with no milk; 1Â½ cups of steamed vegetables for lunch, and 2Â½ cups of steamed vegetables for dinner. She said she drinks a lot of water to feel fuller.
She said she sometimes feels lethargic on fasting nights, and occasionally overindulges on evenings before a fast. Still, overall, she believes the diet is easier than counting calories on a daily basis.
"My friends, they all kind of already started on it by themselves because they thought this was a pretty nice way of doing things," she said.
"At the beginning, it can be difficult because people, especially in the U.S., they think they are always hungry, and they want to have always something in their hand to drink or to eat, but I think it's psychological," Fontana said.
Most participants have successfully stayed in the program.