Lose Weight - Any Amount - and Sleep Better

By Ken Mallows

The act of losing weight – not necessarily trimming down to your ideal weight  – may help you sleep better, according to researchers from the Perelman School of Medicine at the University of Pennsylvania.

Doctors know that obesity can lead to sleep-robbing factors such as snoring and sleep apnea, but they are not clear on how much weight a person needs to shed in order to see an improvement in sleep. This research shows that mice who lost weight slept fewer hours and showed increased alertness than mice who didn't lose weight despite how much they lost or at what weight they started and ended.

In this research, half of the mice received their normal diet while the other half received a high fat diet. In fact, they ate three times more fat for eight weeks. At the end of that period, some of the mice were switched to the alternative diet for one week causing the high fat content mice to gain weight and the newly fed normal diet to lose weight. The rest of the mice consumed their current diet.

A week later, nine weeks total, mice who ate the high fat diet weight 30 percent more, slept more than one hour longer per day, and showed signs of drowsiness during the day compared to the regular diet mice. The “diet switch” groups, however, had similar body weight at week nine, but completely different sleep/wake profiles when compared to each other.

“Our findings suggest body weight is a less important factor than changes in weight for regulating sleepiness,” said the study’s lead author, Isaac Perron, a PhD student in Neuroscience at the University of Pennsylvania. “Diet-induced obese mice that ate a regular chow diet for only one week showed the same sleep/wake profile as mice that ate a regular chow diet for nine weeks.”

The implications for humans is that losing some weight, no matter how much, can improve sleep quality.

 “The diet consumed during the final week was key to driving the sleep effects, independent of the starting body weight,” said Perron. “If you’re overweight and often feel tired, you may not need to lose all the weight to improve sleep, but rather just beginning to lose that excess weight may improve your sleep abnormalities and wake impairments.”

The research was published in the current issue of the journal Sleep.