It’s estimated that 50-70 million people in the U.S. have sleep or wakefulness disorders, resulting in poor quality sleep. We’ve already learned that a lack of sleep can lead to packing on some pounds due to an increased fast food craving, but scientists have recently found that what time you go to bed also can have the same negative effect.
The study included 96 participants between the ages of 18 and 50 who were healthy and slept 6.5 hours or more at night. For seven days, the participants wore actigraphs to monitor their rest and activity cycles and track their food intake and physical activity.
When researchers analyzed the information from the actigraphs with circadian rhythms and participants’ body fat, they found that those who went to bed later ate more unhealthy food, less vegetables, and worked out less. Despite this, later sleep times were also linked to a lower body mass index.
"Our results help us further understand how sleep timing in addition to duration may affect obesity risk," lead investigator Dr. Kelly Glazer Baron, of the Feinberg School of Medicine at Northwestern University, said in a statement. "It is possible that poor dietary behaviors may predispose individuals with late sleep to increased risk of weight gain."
Researchers hypothesize that circadian rhythms and our sleep-wake cycle could be associated with metabolism, and that disrupting them could lead to obesity. Poor sleep has long been linked to health issues, such as diabetes, mental health problems, and heart problems.