Sleep Deprivation Affects Teen Appetites

Teenagers—especially girls—who regularly sleep less than eight hours a night tend to eat more fatty and sugary foods than those who maintain adequate sleep schedules, according to a study published in yesterday’s issue of the journal Sleep.

The study, headed by Susan Redline, a professor of medicine at the Harvard-affiliated Brigham and Women’s Hospital, attempted to connect findings about decreased sleep and increased obesity rates among teenagers.

“The message really is that adequate good sleep is really important for good health, and poor sleep is definitely contributing to the obesity epidemic our population is witnessing,” Redline said.

Redline added that she hopes these findings will draw attention to the importance of good sleep alongside healthy diet and exercise.

The study followed 240 adolescents between 16 and 19 in the Cleveland area, tracking their sleep durations and self-reported food intake.

After adjusting for potential confounders such as weight, gender, obesity, and race, the researchers found that teenagers who slept less than eight hours a night consumed on average 2.2 percent more fats.

For each hour of decrease in sleep, there was a 0.8 percent increase in consumption of fatty and sugary foods.

This correlation is consistent with previous research, said Frank B. Hu, professor of nutrition and epidemiology at the Harvard School of Public Health.

Previous studies have shown that sleep deprivation affects appetite-regulating hormones, specifically by decreasing leptin, an appetite suppressor that causes the feeling of fullness, and increasing ghrelin, a stomach hormone that stimulates the appetite.

“When people are hungry, they crave high energy density foods high in fats and sugars,” said Hu. “The amounts of fat and sugar in our diets are already very high, and when hormonal changes induce hunger, it’s not surprising that kids will reach for such types of foods.”

Apart from hormonal changes, which Redline said was currently the strongest hypothesis, other potential explanations are that shorter sleepers have more opportunities to eat simply because they are awake longer, or that the adolescents are eating as a stress response to sleep deprivation.

Redline said that this link may explain the “freshman 15” phenomenon many college students experience.

College surveys have shown that some freshman get less than five hours of sleep at night, a result of living in an environment in which they go to sleep very late but still get up early for class, said Redline.

“In response to the stress of sleep deprivation and exams, many students turn to late-night snacking or junk foods,” she said.

—Staff writer Helen X. Yang can be reached at hxyang@fas.harvard.edu.