By Alexandra Sifferlin Nov. 01, 2012
What does sleep have to do with weight? The latest research finds a link between lack of sleep and hunger.
New research published in the journal SLEEP shows that getting more shuteye could lead to less overeating, and that lack of sleep has different influences on hunger in men and women.
To take a closer look at the hormonal effects of sleep restriction on hunger, the researchers brought 27 healthy men and women into a sleep lab and manipulated the amount of time they slumbered. In the first condition, the participants slept for four hours a night for three nights in a row. Three weeks later, they were allowed to sleep for nine hours a night for three consecutive nights.
In order to measure any changes in the body’s response to the altered sleep patterns, the scientists took blood samples from the volunteers and recorded glucose, insulin, leptin and other hormone levels — all of which are involved in the chain of metabolic signals that lead to hunger.
The researchers found that men under restricted sleep conditions experience increases in the hunger-stimulating hormone ghrelin while women in the same conditions did not see heightened ghrelin levels, but instead had reduced levels of the hormone GLP-1, which is produced by the intestinal cells while we eat and tends to suppress appetite. Ghrelin is released by the stomach and pancreatic cells and surge before meals and start to decline after meals. Men in sleep deprived conditions, in other words, were more likely to feel hungry and have larger appetites while women losing shut eye tend to feel less full — both slightly different parts of the same chain of metabolic signals that contribute to hunger.
While the metabolic difference seems subtle, after a few sleepless nights, the authors say, both conditions can lead to overeating. And indeed, that’s what the researchers saw — participants ate about 300 calories more after losing sleep than when they had a full night’s rest.
“Our results point to the complexity of the relationship between sleep duration and energy balance regulation,” study author Marie-Pierre St-Onge, a research associate at New York Obesity Research Center at Columbia University 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.”
Although the biological mechanisms underlying sleep-related hunger requires further study, the bottom line appears to be that our bodies are designed to see food differently when we don’t get enough rest. In addition to focusing on diet and exercise, then, it’s just as important to remember to get a good night’s sleep in order to maintain a healthy weight.