You know what you should eat. But do you know when you should eat?

Carbs will be carbs at any time of day, but according to new research, how our bodies respond to sugar and other substances varies greatly. Findings show that the time of a meal may be just as important to weight loss as the calories consumed.

Investigators worked with 420 adults who were enrolled in a 20-week weight loss treatment program. Individuals were placed into one of two groups by their own choosing — early eaters, who ate lunch as a main meal anytime before 3 p.m., and late eaters, who consumed lunch after 3 p.m.

After four months, the researchers found that early-eaters lost significantly more weight than late-eaters, and recorded a much quicker rate of weight-loss. Published in the International Journal of Obesity, the first-of-its kind study also showed that late-eaters had a lower estimated insulin sensitivity, which is a risk factor associated with diabetes.

The timing of smaller meals did not affect weight loss. However, the late eaters did consume fewer calories during breakfast and were more likely to skip breakfast altogether, perhaps leaving them more hungry and more likely to consume added calories during the rest of the day.

In examining the participants’ weight loss, the researchers also looked at other possible mitigating factors, like total calorie intake, exercise and sleep patterns. Even when taking these into account, the findings were unchanged, suggesting that the timing of the main meal was indeed a key and independent factor in weight loss success.

Based on the findings, the researchers suggested that health care providers continue to promote healthy eating patterns via diet and exercise. But they also suggest putting a little thought into when dinner happens and not just what is on the plate.