For Weight Loss Success, Timing is Everything: Don't Eat Late

It's another new thing to worry about when you're trying to lose weight: don't eat a late lunch. A new study found that dieters that ate an earlier lunch lost more weight on average.

In this latest collaborative study, researchers at the Brigham and Women's Hospital, Tufts University and the University of Murcia monitored 420 overweight participants during a 20-week weight loss program in Spain. These volunteers were split into two groups that consisted of early-eaters and late-eaters. Since lunch is considered the largest meal in Spain, composed of about 40 percent of the day's calories, half of the participants ate lunch before 3 p.m. while half ate lunch after 3 p.m.

The researchers found that the late-eaters lost less weight overall and shed pounds at a slower rate than those who ate earlier. In addition, those eating lunch later were more likely to skip breakfast or eat fewer calories (even though dieters are often advised to eat breakfast). The actual timing of breakfast and dinner, though, didn't influence weight loss effectiveness for either group. The researchers also made sure to cover their bases, factoring in total caloric intake, energy expenditure, the appetite hormones leptin and ghrelin and amount of sleep. However, they found that these factors were similar in both groups.

Overall, they found that those who ate lunch earlier lost an average of 22 pounds in 20 weeks, while those who ate later lost only about 17 pounds. Although researchers were unsure why weight loss was greater in the early eaters, they hypothesized that glucose is processed differently depending on the time of day. In addition, the timing of meals may impact the circadian system (the body's inner clock), which could disrupt the proper function of the liver and fat cells.

Whatever the case may be, you probably want to eat your big meal earlier in the day if you're planning on losing weight.