MONDAY, April 28, 2003 (HealthDayNews) -- Could fasting every other day improve your health and reduce your risk of disease?
Maybe. Skipping meals every other day is as beneficial for rodents' health as eating a lower-calorie diet, even if they gorged on food on their eating days, reports a study from the National Institute on Aging. Results of the study appear in the April 28 issue of the Proceedings of the National Academy of Sciences.
"In normal adult mice, a reduction in meal frequency is clearly beneficial," says the study's lead author, Mark Mattson, chief of the Laboratory of Neurosciences at the National Institute on Aging in Baltimore. Mattson says the mice had improved regulation of their blood sugar and less brain damage when exposed to a substance that mimics the damage done by stroke, Parkinson's disease and Alzheimer's disease.
"It's important to look at this issue in humans," he says. "It's only recently in human evolution that we've had free access to food. Our ancestors often had to go days without food. As far as I know, there's no evidence that it's better to eat three meals a day."
For this study, Mattson and his colleagues put three groups of mice on different diets. The first group could eat however they wanted. The second was fed a restricted-calorie diet, which contained about 40 percent less food than they normally ate.
The third group was given food every other day. On the days they ate, their diets were unrestricted, and according to Mattson, they usually gorged and made up for all of the calories they had missed the previous day.
After 20 weeks, the researchers tested the blood glucose levels of the mice. Between 21 and 27 weeks into the study, the mice were injected with a substance called kainite. Kainite is a neurotoxin that causes brain damage, similar to the damage caused by neurodegenerative disorders such as stroke and Alzheimer's disease.
"The beneficial effects of [the meal-skipping diet] were as great as the beneficial effects of the calorie-restricted diet," says Mattson. The meal-skipping mice "showed improvements in glucose regulation and improved outcome in a model of neurodegenerative disorder."
Does this mean humans should start skipping meals or fasting for whole days?
Probably not, says Mattson, who says more work needs to be done to see if these results hold true for humans. But, Mattson adds, as long as you're a healthy adult, it's probably OK to skip a meal sometimes, though he doesn't recommend anyone go all day without food.
Samantha Heller, a nutritionist from New York University Medical Center, agrees that more work needs to be done before anyone can recommend a change in the way people are eating.
"This is a preliminary study looking at mice," she says. "There is no data on humans."
Plus, she says, fasting for a day would probably never be a realistic choice for people. "One of the problems with people dieting is they starve themselves and once they start eating again, they can't stop eating," she explains. "It's very hard to make a healthy choice when you get that hungry."
More information
Get some tips on losing weight and keeping it off from the American Academy of Family Physicians or the U.S. Food and Drug Administration.
