Less Sleep Linked to Obesity in African Americans

A new study examined associations between body mass index (BMI) and reported amounts of sleep, using data from 3,778 African Americans. Researchers found more sleep was associated with a lower BMI, while less sleep was associated with a higher BMI.

The research, published in The Journal of the American Osteopathic Association, notes some minority populations are more susceptible to becoming overweight or obese, however prior studies have not focused on them.

“The good news is sleep is something most people can control, regardless of other factors, like income and education levels,” says Trimella Jefferson, MPH, an epidemiologist at the Mississippi State Department of Health, and lead author on this study. “Spreading that information can be very empowering, especially to communities that struggle with obesity.”

About 30% of participants were overweight, with two-thirds of women and half the men categorized as obese. The average reported sleep duration of slightly more than six hours fell far short of National Sleep Foundation recommendations of 7 to 9 hours of sleep for adults aged 18-64.

Sleeping less than the recommended amount may result in weight gain because it leaves people with dysregulated appetites and less energy for exercise due to fatigue, the authors noted.

Researchers say physicians and healthcare providers can help by sharing information about the role of sleep in overall health and providing tips for better sleep hygiene. These include:

• Set a bedtime early enough to get seven hours of sleep
• Keep television and other screens and devices outside the bedroom
• Keep the bedroom dark and at a comfortable, cool temperature
• Turn off electronic devices at least 30 minutes before bedtime
• Avoid large meals, alcohol and caffeine before bedtime
• Reduce water and fluid intake before bedtime

Jefferson and her colleagues used data from the Jackson Heart Study, the largest, longitudinal epidemiologic investigation of cardiovascular disease and risk factors among African Americans. The study population consisted of men and women aged 21 to 84 years, in Jackson, Mississippi. The researchers examined a subset of JHS participants to better understand the link between sleep and obesity.