For Weight Loss, Is When You Eat as Important as What You Eat?

Do you follow the folk wisdom practice of eating like a king for breakfast, a prince for lunch and a pauper for dinner? Or do you hoard your calories and eat like a pauper throughout the day and like a king at night? If you tell me what time of day you eat your main meal, I’ll tell you whether you’ll be successful in your weight-loss efforts.

This declaration is based on a large-scale study, reported in the January 2013 issue of the International Journal of Obesity, conducted by researchers from Brigham and Women’s Hospital and Tufts University in the United States and the University of Murcia in Spain.

Researchers followed 420 individuals who enrolled in a 20-week weight-loss program in Spain. The individuals were divided into two groups: early eaters and late eaters. Early eaters ate a Mediterranean-style lunch before 3 p.m., and late eaters ate their lunch after 3 p.m. During this meal, about 40 percent of the day’s calories were consumed.

The study revealed that late eaters lost “significantly less weight” than early eaters and lost weight at a slower rate. Late eaters also had lower insulin sensitivity, which is a risk factor for diabetes.

In reaching this conclusion, researchers took into account the total calories consumed, energy expenditure, amount of sleep and other variables. Since there were no significant differences between the early eaters and late eaters in these variables, the researchers concluded that the time of the meal was the determining factor for weight-loss success.

Frank Scheer, PhD, MSc, assistant professor of medicine at Harvard Medical School, was the senior author of this study, and his conclusion suggests how we can apply this insight in our daily routines: “Our results indicate that late eaters displayed a slower weight-loss rate and lost significantly less weight than early eaters, suggesting that the timing of large meals could be an important factor in a weight loss program.”

Folk wisdom has a bad reputation for offering contrary advice. For example, “Absence makes the heart grow fonder” contradicts “Out of sight, out of mind.” And “Opposites attract” disputes “Birds of a feather flock together.” But in this case, Grandma’s advice to eat a hearty breakfast, a solid lunch and a light supper is spot on. Researchers tell us that to improve our chances for successful weight loss, we need to eat our biggest meal midday rather than consume the traditional calorie-laden evening meal.

Photo: stevendepolo on Flickr