Sleep Loss Linked to Eating More and Moving Less, Research Suggests

Insufficient sleep may contribute to weight gain by influencing both eating and daily activity, according to research discussed by the University of Colorado Anschutz. The evidence includes controlled sleep studies in adults, observational findings across age groups and intervention research involving people and teenagers with chronically short sleep.

Studies that restrict adults’ sleep have repeatedly found that participants consume roughly 200 to 300 additional calories, according to Seth Creasy, an associate professor of endocrinology, metabolism and diabetes. In another intervention, people who typically slept fewer than six hours extended their sleep for two weeks, reaching about seven and a half hours per night. They subsequently ate approximately 270 fewer calories per day without being instructed to change their diet, Creasy said.

The research does not establish that inadequate sleep alone causes obesity. Creasy described diet and physical activity as the two main behavioral drivers of weight gain, while sleep may support both. The findings instead point to several ways sleep loss could be associated with weight-related behavior.

Shorter sleep has been linked with changes in leptin and ghrelin, hormones involved in hunger and satiety, as well as changes in the brain’s reward system. Researchers cited in the report said tired people may feel hungrier, less satisfied after eating and more drawn to readily available high-sugar or high-fat foods. The source also notes that people burn energy while awake or restless, meaning energy expenditure by itself does not explain the observed relationship with weight.

Physical activity may also change after poor sleep. In one study involving New York City residents, researchers restricted sleep for six weeks and monitored participants in their everyday environment. Participants became more sedentary and spent more time sitting, even after accounting for the amount of time they were awake.

Adolescents may face additional challenges. Their biological clocks naturally shift later, making it difficult to fall asleep early, while early school schedules can reduce sleep during the school year. The report says an estimated 70% of high school students and 30% of adults do not obtain their recommended amount of sleep. Anxiety, busy schedules and extensive electronic-device use were also identified as factors affecting teens’ sleep.

In studies by Stacey L. Simon’s team, adolescents were given schedules allowing at least one additional hour in bed on school nights. They obtained more sleep and showed a reduction in sedentary behavior during the study period.

Short sleep duration and later sleep timing in adolescents have also been associated with poorer insulin sensitivity, which researchers said could increase future risk for obesity and type 2 diabetes. Early evidence suggests adolescent females may have earlier circadian timing, higher insomnia levels and potentially greater unmet sleep needs than males, although the source describes this area as still under-researched.

The researchers hope these findings can inform behavioral approaches to weight management across the lifespan, but the evidence presented describes sleep as a contributing factor rather than a replacement for established attention to diet and physical activity.