It's familiar advice to dieters: Eat five small meals a day, instead of two big ones, and you'll stave off hunger and lose more weight.
Except that it may not work that way.
According to a new British study, the total number of calories, not meal frequency, is what counts. Women who ate two big meals a day burned the same amount of calories as women who ate five small meals. In other words, it's the total amount of calories we eat, not how we eat them, that matters for weight loss.
"The size or frequency of the meal doesn't affect the calories we burn in a day," said lead study author Milan Kumar Piya, M.D., clinical lecturer with the U.K. National Institute for Health Research. "If you eat two meals or five, as long as it's the same number of calories, there is no difference in energy expenditures, so there is no effect on weight loss," he told HealthDay.
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There was, however, one big difference between those who ate several small meals and those who didn't. For overweight women, eating more often increased the amount of inflammation in the body, something that didn't happen in women of normal weight.
The findings, which were presented last week at the Society for Endocrinology annual meeting in Liverpool, England, involved 24 women, both lean and obese. The average age of the lean women was 34, while the obese women were, on average, 42. On two separate days, each group was given either two big meals or five small meals, both totaling the same amount of calories. The researchers measured the number of calories burned by both groups. They also took blood samples that detected endotoxins, a marker for inflammation.
The heavier women had a significantly higher level of endotoxins after eating five small meals than did the leaner women, researchers found. Endotoxins have been linked to a higher risk of diabetes and heart disease, and Piya wrote in an email that "our previous studies have shown that endotoxin is higher in obese and type 2 diabetes subjects."
Granted, this was a small study conducted over a limited period of time. Weight-management expert Sherry Pagoto, a psychologist and University of Massachusetts associate professor of medicine, cautions that "the conclusions that can be made from this study are a bit limited, as they only had participants use each approach on a single day," she told AARP in an email.
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A recent analysis of research finds no clear evidence about the role that meal frequency plays in weight loss, although some studies showed that eating fewer meals helped obese people better control their cholesterol, said author Michelle Kulovitz Alencar, assistant professor of kinesiology at California State University, San Bernardino. Her study was published in the April issue of the journal Nutrition.
Alencar thinks that, for now, people should stick with the approach they are used to. She told HealthDay that those who switch their patterns - going from three meals a day to five, or the reverse - may "throw off" their hunger hormones, leading to a feeling of being hungrier in some cases.
Pagoto also tells her patients to stick with what works. She does agree, though, that "so far we have not found a better approach" than counting calories. "It's cumbersome and prone to error," she admits. Still, those who track their calories the longest are the most successful at losing weight.
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