Lack of sleep may hinder weight loss

A small study published Monday afternoon in the Annals of Internal Medicine suggests that getting too little sleep can impede weight-loss efforts.

In the study, conducted by researchers from the University of Chicago and the University of Wisconsin and funded by the National Institutes of Health, 10 sedentary, overweight people ages 35 to 49 were placed on a moderately calorie-restricted diet and observed for two 14-day periods. During one period they spent an average of 5.5 hours in bed per night; during the other, 8.5 hours a night.

The shorter time in bed was associated with less loss of body fat, with more of the overall weight lost coming from lean body tissue. That can further slow weight loss, as the more lean mass you have, the more readily you burn calories.

Folks who also reported feeling hungrier had more of the appetite-trigger hormone grehlin circulating in their bodies when their sleep was restricted.

The study notes that more, and larger-scale, research is needed to tease out the precise ways in which sleep, or the lack thereof, relates to weight and weight management. In the meantime, those of us who are trying to keep our weight in check might want to make sure we get enough sleep. Can't hurt, right?

And just how much sleep is enough? Different people have different needs, of course, but the standard recommendation has long been for adults to get eight hours of sleep a night. However, recent research on the link between sleep duration and mortality among women shows that five or six hours of shut-eye may be optimal.