Meal Consistency Enhances Metabolism
In last two decades, traditional low meal frequency patterns (2-3 times/day) got slowly replaced by higher meal frequencies (5-7 times/day). There are essentially four factors that affect a person’s overall energy expenditure throughout the course of a 24 hour period. Those factors are basal metabolic rate (BMR; also termed resting metabolic rate [RMR]), diet induced thermogenesis of food (DIT; also known as the thermic effect of food [TEF]), exercise thermogenesis (EEx), and spontaneous movement, termed non-exercise activity thermogenesis (NEAT).
It has long been a myth that eating more frequently will increase your metabolism as the newer research suggests there is no significant differences in metabolism in those that eat more frequently compared to those that eat less frequently. Given the same amount of calories for the day, it does not matter, it’s really a matter of preference.
As you can imagine, if you are eating three big meals, at breakfast, lunch, and dinner, as opposed to smaller meals spread out throughout the day, the larger meals are going to produce greater spikes in insulin in glucose compared to smaller meals.
In one study, a low-frequency diet showed significantly higher peaks and lower troughs for glucose and insulin levels, as would be expected with less meal eating frequency. However, the 24 hour glucose (a measure of total blood glucose exposure) was significantly lower in the low-frequency diet, suggesting superior glycemic control. This makes sense as if you’re eating less meals, insulin and glucose levels are going to be lower as opposed to insulin and glucose spiking every 2-3 hours over the course of the day.
One of the most important factor for dieting is to have consistent, regular meals plans throughout the day, skipping meals is not conducive for losing weight, in fact the newest study out of the Proceedings of the Nutrition Society reported that meal consistency is key for obesity prevention. This does not mean eating more frequently is means being consistent in what you eat every day.
Several experimental studies have shown that erratic eating (different numbers of meals on each day) is associated with potentially deleterious alterations in lipid and carbohydrate metabolism. Some dieters tend to fluctuate how many meals a day they are eating.
Irregular eating can lead to weight gain and the development of obesity. Researchers investigated the effect of irregular meal frequency on postprandial energy expenditure and anthropometric measurements in healthy women. In the study, 11 healthy weight women (18– 40 years) were studied in a randomized crossover trial with two phases of 2 weeks each. In Phase 1, participants consumed either a regular meal pattern (6 meals/day) or an irregular meal pattern (varying from 3 to 9 meals/day). In Phase 2, participants followed the alternative meal pattern to that followed in Phase 1, after a 2-weeks washout period.
In the two phases, identical foods were provided to a participant in amounts designed to keep body weight constant. Participants came to the laboratory after an overnight fast at the start and end of each phase. At the end of the 14 day study, there were no significant changes in body weight and anthropometric measurements after both meal pattern interventions. There was also no significant difference in mean daily energy intake between the regular and irregular meal pattern. Fasting RMR showed no significant differences cross the experiment visits. However, there was a significant difference in total postprandial energy expenditure by visit.
Postprandial energy expenditure after the regular meal pattern was significantly higher than at baseline after the irregular meal pattern. Eating regularly for a 14-day period significantly increases postprandial energy expenditure which may contribute to weight loss and obesity management, but further studies are needed in obese participants.
In summary, the researchers found that sticking to a consistent meal plan over the course of 2 weeks was better for a person’s metabolism as opposed to irregular eating even though the caloric intake was the same.
Alhussain, M, M. A. Taylor and I. A. Macdonald. “Influence of the constancy of daily meal pattern on postprandial energy expenditure in healthy weight women”. Proceedings of the Nutrition Society, 74, E141 (2015): doi:10.1017/S0029665115001561.