Late sleepers eat more calories and have higher BMIs, putting them at risk for type 2 diabetes

Individuals who regularly stay up late may be more likely to eat excess calories and have a higher body mass index (BMI), putting themselves at risk for developing type 2 diabetes, according to new research out of Northwestern University.

The findings, which were published in the journal Obesity, also show that night owls tend to eat far more fast food and significantly less fruits and vegetables than those who go to bed at normal hours.

The researchers said that these types of eating habits can lead to dramatic weight gain and take a toll on an individual’s metabolic system. Rapid weight gain and a high BMI have been shown to predispose a person to type 2 diabetes and jeopardize their long-term health.

For the study, the investigators surveyed 51 individuals about their daily eating and sleeping habits. Twenty-three of the participants were late sleepers while the remaining 28 slept during more typical hours.

The results of the survey indicated that late sleepers consumed an average of 248 more calories per day. They drank significantly more full-calorie soda, ate twice as much fast food and included half as many fruits and vegetables in their daily diet. On average, the BMIs of late sleepers were considerably higher.

Phyllis Zee, MD., who participated in the research, said that metabolism and sleep cycles are closely linked, and that changing one or the other can have broad effects that may impair an individual’s health and put them at greater risk of developing type 2 diabetes.

"Human circadian rhythms in sleep and metabolism are synchronized to the daily rotation of the Earth, so that when the sun goes down you are supposed to be sleeping, not eating," Zee said. "When sleep and eating are not aligned with the body's internal clock, it can lead to changes in appetite and metabolism, which could lead to weight gain."