Chronic Sleep Loss and Obesity
By Cynthia K. Buffington, PhD
How much sleep do you get each evening? Seven to eight hours? Six hours or less? Did you know that chronic sleep loss increases your risk for weight gain and obesity?
Studies find that adults who sleep for less than seven to eight hours have an increased risk for weight gain and obesity, as well as a reduced capacity for weight loss when on a diet. This means that not obtaining sufficient amounts of sleep can interfere with your maximal weight loss success after surgery and can contribute to weight regain.
The link between sleep loss and obesity has both a behavioral and biological basis. Behaviorally, sleep loss increases the risk for obesity by lengthening the time available for food or beverage consumption. Studies find that individuals who obtain the least amount of sleep consume the highest number of snacks each day and tend to have eating irregularities, including a reduced desire for nutritious foods such as fruits and vegetables and a ‘craving’ for foods high in calories and processed carbohydrate (cakes, candies, cookies, chips, etc.). Sleep loss also contributes to obesity by reducing the desire for physical activity and the amount of calories your body burns through movement.
Biologically, sleep loss increases ghrelin, also known as the hunger hormone, which stimulates appetite and contributes to fat accumulation. Leptin, a hormone produced by adipose tissue, declines with weight loss and this decline can lead to an increase in appetite and reduction in metabolism. Studies find that the changes in ghrelin and leptin with shortened sleep duration increase an individual’s desire for cookies, cakes, candy, chips and other high-caloric foods. In addition to ghrelin and leptin, sleep loss also causes changes in the production of other hormones, such as cortisol, growth hormone and adiponectin, that can increase the body’s capacity to store fat.
In all of these ways and possibly many more that have yet to be identified, sleep loss is linked to obesity. But, there is good news! Sleep is a modifiable effector of weight gain, meaning, we can reduce the risk for weight gain by increasing the duration of our sleep – seven to eight hours for adults, nine to ten hours for adolescents, ten to twelve for children, and twelve hours or more for babies.