Media articles and nutritionists alike have perpetuated the idea that for healthy metabolisms individuals should consume small meals multiple times a day. However, new research conducted at the University of Missouri suggests all-day snacking might not be as beneficial as previously thought, especially for obese women.
"Our data suggests that, for obese women, eating fewer, bigger meals may be more advantageous metabolically compared to eating smaller, more frequent meals throughout the day," said the study's lead author, Tim Heden, a doctoral student in MU's Department of Nutrition and Exercise Physiology. "Eating larger meals less often lowered blood-fat levels. Over time, consistently eating fewer, larger meals each day could lower the women's blood-fat levels and thereby lower their risk of developing heart disease."
Heden and other MU researchers studied how meal frequency affected blood-sugar and blood-fat levels in eight obese women throughout two 12-hour periods on two separate days. All of the women consumed 1,500 calories. During the two different testing days, the participants consumed three 500-calorie liquid meals or six 250-calorie liquid meals. Throughout the 12-hour time frames, researchers tested sugar and fat levels in the women's blood every 30 minutes. Women who consumed three meals had significantly lower fat in their blood.
"The mass media and many health care practitioners often advocate eating several small meals throughout the day," Heden said. "However, when we examined the literature, we didn't find many studies examining or supporting this popular claim. This lack of research led to our study, which is one of the first to examine how meal frequency affects insulin and blood-fat levels in obese women during an entire day of eating."
More than one-third of Americans are obese, and these individuals are especially at risk for heart disease, the leading cause of death in the country, according to the Centers for Disease Control and Prevention. Heden says the research could help nutritionists and medical professionals develop strategies to improve the health of obese women.
"With multiple meals throughout the day, you have to be careful. If you start consuming several meals, there's more potential to overeat or to make unhealthy snack choices with easily accessible junk food," said Jill Kanaley, professor in the Department of Nutrition and Exercise Physiology and study co-author. "Some people are good at making efforts to eat healthy snacks; however, most people aren't, and they end up taking in too many calories. The more times you sit down to eat, the more calories you're probably going to take in."
Obese women would benefit from consuming three balanced meals a day, Heden and Kanaley agree.
More information: The study, "Meal Frequency Differentially Alters postprandial Triacylglycerol and Insulin Concentrations in Obese Women," will be published in the journal Obesity.