Trying to Lose Weight? Get in Enough Sleep, Study Says

Regardless of diet and exercise, researchers say the key to losing weight is getting enough sleep. In a new study released Tuesday, scientist say lack of sleep causes changes in brain activity that lead to people feeling hungrier and craving more fattening foods.

Research published Aug. 6 in Nature Communications found that sleeping enough hours a day and weight loss go hand-in-hand. A causal link was suspected, but science has not been able to explain the mechanism, until now.

"What we have discovered is that high-level brain regions required for complex judgments and decisions become blunted by a lack of sleep, while more primal brain structures that control motivation and desire are amplified," study senior author Matthew Walker, a UC Berkeley professor of psychology and neuroscience, said in a press release.

For the study, 23 participants had their heads scanned twice; once after a full night of sleep and once after being deprived their shut-eye for a night -- their brain activity measured the next day as they selected items and portion sizes from pictures of 80 different food types.

Among the fatigued individuals, the researchers noted impaired activity in regions of the cortex that evaluate appetite and satiation. Simultaneously, there was a boost in areas associated with craving.

"An additionally interesting finding was that high calorie foods became more desirable to the sleep deprived participants," said study co-author Matthew Walker of the psychology department at the University of California in Berkeley.

"These findings of impaired brain activity in regions that control good judgment and decision making together with amplified activity in more reward-related brain regions fit well with, and potentially explain, the link between sleep loss, weight gain and obesity," he told AFP by email.