Prior research has shown how not getting enough sleep can impact your weight, but a new study finds the consistency of your bedtime and wake time can also influence body fat.
Researchers from Brigham Young University in Utah studied 330 female university students over the course of several weeks, finding that those with the best sleeping habits had healthier weights. Women with a consistent bedtime and, more importantly, a consistent wake time had lower body fat than those with more erratic schedules. Also, findings showed that getting less than 6.5 or more than 8.5 hours of sleep per night was associated with higher body fat.
Women in the study were first assessed for body composition, and then were given an activity tracker to record their movements during the day and their sleep patterns at night. Researchers tracked sleep patterns of the participants for one week.
Wake time was particularly linked to body fat, the researchers said. Subjects who woke up at the same time each morning had lower body fat – so staying up late and sleeping in may be doing more harm than good, head researcher and exercise science professor Bruce Bailey said.
“We have these internal clocks and throwing them off and not allowing them to get into a pattern does have an impact on our physiology,” he added.
To improve sleep quality Bailey recommends exercising, keeping the temperature in the room cool, having a dark, quiet room, and using beds only for sleeping.
“Sleep is often a casualty of trying to do more and be better and it is often sacrificed, especially by college students, who kind of wear it as a badge of honor,” Bailey said.
Findings, announced November 18, are published online in the American Journal of Health Promotion.