11/05/2012 08:23 am ET Updated Nov 05, 2012

Sleep Deprivation Could Up Calorie Intake -- But The Reason Why May Differ For Men And Women

Past research has indicated a relationship between sleep and calorie intake -- mainly that the less you sleep, the more you tend to eat throughout the day. But now, a new study shows that sleep may affect the hormonal process that dictates food intake differently between men and women.

Specifically, researchers found that not getting enough sleep was linked with lower GLP-1 hormone levels -- which affects satiety -- in women, but not men, and increased ghrelin hormone levels -- which affect hunger stimulation -- in men, but not women.

"Our results point to the complexity of the relationship between sleep duration and energy balance regulation," study researcher Marie-Pierre St-Onge, Ph.D., of the New York Obesity Nutrition Research Center at St. Luke's/Roosevelt Hospital, said in a statement. "The state of energy balance, whether someone is in a period of weight loss or weight gain, may be critical in the metabolic and hormonal responses to sleep restriction."

The study, published in the journal SLEEP, included 27 men and women between the ages of 30 and 45 who were all of normal weight. Their blood was drawn at the beginning of the study, and then they underwent two different sleep conditions: In one, they were sleep deprived by only getting four hours of sleep; in the second, they got a typical nine hours of sleep.

Researchers said the study suggests that decreases in sleep may increase calorie intake for both men and women, but it may do so in different ways -- for men, by giving them a bigger appetite; for women, by making them feel less full.

Recently, a review of 18 studies in the Journal of the Academy of Nutrition and Dietetics showed that getting less than a full night's sleep could spur changes in hormones linked with weight and energy balance.

"Partial sleep deprivation may influence appetitive hormones, such as ghrelin and leptin, that aid in the regulation of appetite and body weight. Because weight loss also produces alterations in ghrelin and leptin to increase hunger, this may be compounded by the effects of partial sleep deprivation," the researchers wrote in the study.

For more surprising ways sleep deprivation could affect your health, click through the slideshow:

Signs You Need More Sleep