Researchers at the University of Chicago, in Illinois, determined whether sleep restriction attenuates the effect of dieting on excess adiposity.
First, the details.
10 overweight nonsmoking adults with an average body mass index (BMI) of 27.4 (overweight) participated in 14 days of moderate caloric restriction plus either 8.5 or 5.5 hours of nighttime sleep opportunity.
Loss of fat and fat-free body mass was recorded.
Also, changes in substrate utilization, energy expenditure, hunger, and 24-hour metabolic hormone concentrations were measured.
And, the results.
Sleep curtailment decreased the proportion of weight lost as fat by a significant 55%.
It also increased the loss of fat-free body mass by a significant 60%.
These changes were accompanied by enhanced neuroendocrine adaptation to caloric restriction, increased hunger, and a shift in relative substrate utilization toward oxidation of less fat.
The bottom line?
The authors concluded, “The amount of human sleep contributes to the maintenance of fat-free body mass at times of decreased energy intake. Lack of sufficient sleep may compromise the efficacy of typical dietary interventions for weight loss and related metabolic risk reduction.”
These results highlight the importance of sleep while dieting. It’s possible that insufficient sleep may compromise many of the factors that contribute weight loss during dieting.
John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.