Sleeping too little promotes weight gain
Not getting a good night's sleep can lead people to pack on pounds over time, say researchers who suggest regular sleep patterns to manage weight.
Researchers in the U.S. reviewed 18 studies on sleep deprivation — getting less than six hours per night — published over 15 years.
The coinciding epidemics of obesity and chronic partial sleep deprivation "seem to be curiously related," lead investigator Dr. Sharon Nickols-Richardson of the department of nutritional sciences at Pennsylvania State University in University Park and her co-authors wrote in Wednesday's issue of the Journal of the Academy of Nutrition and Dietetics.
"Clinicians assisting in weight-loss interventions may improve patient outcomes by discussing sleep time within a healthy lifestyle intervention," the researchers wrote.
"Partial sleep deprivation resulting from lifestyle factors (e.g. work-related stress, shift-work, prolonged light, and television or computer exposure) can be distinguished from partial sleep deprivation caused by medical conditions (e.g. insomnia and obstructive sleep apnea.)"
About 60 per cent (7.6 million) of Canadian men and 44 per cent (5.6 million) of women had an increased health risk because of excess weight, Statistics Canada said last year, based on self-reports. More than 28 per cent of Americans sleep fewer than six hours a night, the researchers said.
They identified a set of patterns, including reduced insulin sensitivity and changes in hormones that influence appetite and intake compared with burning of calories.
Sleep deprivation may increase the risk of overeating at night when circulating levels of the hormone leptin are low, the investigators said. Leptin is thought to promote feelings of fullness. Indeed, people feasting on midnight snacks may overeat less healthful foods.
In one experiment, estimated daily energy intake increased by more than 400 kilocalories on average during partial sleep deprivation. But most of the randomized trials included just 20 participants or less for two nights or less.
Some controlled daily food intake while others allowed people to eat as much as they wanted.
The Canadian Obesity Network includes sleep, time and stress management in its checklist for primary care practitioners counseling patients in obesity management.