In the nutritional world, conventional wisdom suggests that the more often you eat, the more likely you are to burn off those calories and control hunger pangs.

And so the notion of eating six or more "mini-meals" each day, just enough to fuel your body and tide you over until your next bites, has often been recommended as a more waistline-friendly dieting approach than eating three larger meals.

But science evolves, and the answer to whether you should eat many mini-meals or three bigger meals is no longer a straightforward one.

"Years ago, we all believed that you needed to eat multiple times a day to keep your metabolism stoked. ... You had to keep feeding the fire and keep the furnace burning.

But that theory goes back and forth, and newer research is showing that it really doesn't slow metabolism if you're not eating multiple times a day," said Martha McKittrick, a registered dietitian in New York City who has provided weight-loss counseling for over 20 years.

Small frequent meals vs. fewer big meals

Many studies suggest that eating more frequently may offer benefits by decreasing hunger and food intake at subsequent meals. One study involving close to 2,700 women and men found that those who ate at least six times per day ate fewer calories, consumed healthier foods and had a lower body mass index than those who ate fewer than four times over a 24-hour period. Research has also shown that increased meal frequency has positive effects on cholesterol and insulin levels.

But while eating small frequent meals can discourage large swings in blood sugar, decrease hunger and prevent impulsive snacking throughout the day, other studies suggest that eating more often may not be optimal.

And despite the notion that eating more often means more opportunities to burn calories, thanks to the energy involved in digesting, absorbing and metabolizing food's nutrients, research suggests that doing so does not appear to significantly enhance metabolism or total calories burned.

"In the '80s, grazing was thought to be an optimal way of losing weight ... but human studies did not support this at all," said David Levitsky, a professor of nutrition and psychology at Cornell University who has researched the topic of meal frequency and its effects on calorie intake.

"It was thought that if you ate more frequently, the amount of calories you retain would go down, and more calories would be burned. But controlled experiments in humans show that there is no metabolic advantage to eating 12 smaller meals versus eating three or four meals per day, with the same total number of calories."

Other experts agree. "Meal frequency does not affect metabolic rate and thus has no direct effect on weight loss," said Carla Wolper, a registered dietitian and nutrition consultant at the ColumbiaDoctors Executive Health assessment program who spent 25 years on the nutrition faculty at the New York Obesity Nutrition Research Center.

In fact, some research suggests that eating even fewer than three meals may be best in terms of controlling calories: In one study, when individuals skipped breakfast, they consumed about 400 fewer calories for the entire day compared to when they ate breakfast.

"If you decrease the number of occasions to eat, your total calorie intake goes down," said Levitsky, who authored the study. "People think if you skip breakfast, you will overeat later ... and that doesn't happen. Your intake goes up, but not nearly as much as the amount that you skipped."