A study published online by The American Journal of Clinical Nutrition, suggests that even a single night of poor sleep can slow the metabolism and increase hunger.
Associate professor and director of the Sleep Medicine Program at the New York University School of Medicine in New York City, David Rapoport, says that, “One of the more interesting ideas that has been smoldering and is now gaining momentum is the appreciation of the fact that sleep and sleep disruption do remarkable things to the body, including possibly influencing our weight.”
Prior studies have shown that after just a few days of sleep restriction, the hormones that control appetite, leptin and ghrelin, cause people to become hungrier. Ghrelin stimulates appetite, while leptin sends a signal to the brain when you are full. When you don’t get enough sleep, leptin levels decrease, which means you don’t feel as satisfied after you eat. Lack of sleep also causes ghrelin levels to increase, which stimulates your appetite and makes you want more food. The combination of the two result in overeating and consequently, weight gain.
Sanjay Patel, who is the assistant professor of medicine at Case Western Reserve University in Ohio, says that sleeping less affects a person’s basal metabolic rate. This is the number of calories that you burn while you rest. Another contributor to weight regulation is called non-exercise associated thermogenesis, which is involuntary activity such as fidgeting. Patel suggests that if you sleep less, you move around less, too, and therefore burn up fewer calories. An additional consideration in the sleep-weight debate is the impact of sleep on cortisol levels. When you do not get enough sleep, your body releases additional amounts of cortisol (a stress hormone) and this can stimulate hunger.
- Interferes with the body’s ability to metabolise carbohydrates and causes high blood levels of glucose, which leads to higher insulin levels and greater body-fat storage.
- Drives down leptin levels, which causes the body to crave carbohydrates.
- Reduces levels of growth hormone, a protein that helps regulate the body’s proportions of fat and muscle.
- Can lead to insulin resistance and contribute to increased risk of diabetes.
- Can increase blood pressure.
- Can increase the risk of heart disease.