Eating too late can cause weight gain. This was shown by a study conducted by researchers from several American universities, and published in early October in the journal Cell Metabolism. While nutritionists and dieticians already recommended setting aside meals and bedtime by several hours, this study observed precisely what happens in our bodies when we eat too late.
Eat six or two hours before sleeping
Sixteen participants took part in the experiment over six days. Half of them ate 6h40 before going to bed, and the others 2h30 before. In addition to noting their feelings of hunger at different times of the day, participants were given blood tests to measure their levels of the hormones leptin and ghrelin, which cause satiety or hunger. . Finally, the scientists observed the amount of calories burned by their body.
Twice as likely to be hungry
Contrary to what one might think, “people who ate late were twice as likely to be hungry” the next day, the study concludes. The researchers found a higher amount of hunger hormones in the blood of participants who had eaten late the previous day, and they also reported being hungrier than those who had eaten early, when meals were the same. In detail, the level of leptin (which causes satiety) was 6% lower the day after a late meal, while the level of ghrelin (which makes you feel hungry) was 16% higher.
And in addition to being hungrier, people who ate dinner shortly before bed burned about 5% fewer calories the next day than those who ate dinner early. Eating late could therefore lead to a vicious circle that makes us eat more and store more fat.
Our metabolism slows down at night
As an explanation for these multiple differences, the study suggests that they are due to the circadian rhythm. “The circadian rhythm is day and night: our metabolism is more dynamic during the day, with light, and slows down at night, with a recovery around 5 a.m.”, deciphers dietician Florence Foucaut.
Clearly, if we eat shortly before going to bed, most of our digestion takes place while our metabolism is slowed down, which disrupts our functioning. Florence Foucaut is critical of the fact that the study was only conducted on 16 participants, but believes that these results correspond to what is often observed in people who work staggered hours, who are more at risk of obesity.
Although weight gain also largely depends on the composition of meals and physical activity, she does believe that eating late and rich can affect sleep, causing you to wake up more tired and we tend to snack more.