14 DAY TRIAL // A new investigation by researchers in the United States not only revealed that lack of sleep can influence body weight, but also demonstrated that this can occur in a number of ways. The study may highlight a new avenue of research in the fight against obesity.
The investigation was led by specialists at the St. Luke’s-Roosevelt Hospital's New York Obesity Nutrition Research Center (NYONRC). They say that most people – regardless of whether or not they get enough sleep – tend to burn about the same amount of calories daily.
However, sleep-deprived individuals tend to use about 300 more calories per day. Combine that with the fact that it only takes around 3,500 calories to add 450 grams (1 pound) of fat to the human body, and you quickly get a person who puts on weight very fast.
The effect can be very rapid, especially if the individual does not sleep well for prolonged periods of time. Out of the extra calories they need to consume in order to stay awake, the bodies of those who do not get enough sleep can easily produce extra fat for storage.
The new research was led by NYONRC sleep disorder specialist Michael Breus, PhD. He explains that the metabolism of those who get little sleep each night tends to slow down, so that it can conserve as much energy as possible.
When this happens, the human body automatically triggers the release of cortisol, a hormone that promotes appetite. This happens because the body acknowledges the fact that it needs more energy in order to complete the same tasks as when rested.
In addition to cortisol, the body also releases the hormone ghrelin, a chemical responsible for signaling hunger, while at the same time suppressing the production of leptin. The latter is a substance that tells the brain when the stomach is full.
People who exhibit these chemical imbalances feel the need to eat more, but at the same time lack the sensitivity to figure out when they've had enough to eat. “The later you’re up at night, the greater the likelihood that you’re going to eat,” Breus says.
A research paper describing the findings appears in the latest issue of the American Journal of Clinical Nutrition. Experts recommend that people should get at least 7.5 hours of sleep per night, in order to maintain a healthy metabolism, PsychCentral reports.