Eating too much and exercising too little are well-known ways to put on weight, but did you know that losing sleep can also lead to obesity? Interestingly enough, recent studies have proven that fatigue can increase both appetite and vulnerability to weight gain. The percentage of the United States population who are considered obese has been on the rise for many years, and it’s no wonder: it seems everyone now lives high-paced, demanding lifestyles that clamor for instant gratification at all times. In order to accommodate, people are working longer hours and cutting their sleep time by an average of two hours a night1.

Researchers throughout the United States have found that the reason for the weight gain is due to an increase in hormones called gherlin and leptin. Higher levels of gherlin and leptin contribute to a greater feeling of hunger. Dr Shahrad Taheri from the University of Bristol in the UK and her American colleagues found that in people who slept 5 hours per night compared to those who slept 8 hours, leptin and gherlin levels increased up to 15%2.

In another study from author and medical professor Eve Van Cauter at the University of Chicago, 12 healthy men in their 20’s were observed. Those who slept only four hours a night [as opposed to those who slept for 10] experienced an appetite increase of some 24% along with additional levels of the hormones named above, and they tended to crave foods with higher carbohydrate and calorie content such as cookies, candy, and cakes1. Van Cauter’s proof of these increased hormone levels was accompanied by the discovery that less sleep also causes a decrease in metabolism, the process by which your body burns calories. “We found that the metabolic and endocrine changes resulting from a significant sleep debt mimic many of the hallmarks of aging. We suspect that chronic sleep loss may not only hasten the onset, but could also increase the severity of age-related ailments such as diabetes, hypertension, obesity and memory loss3.” Sleep deprivation will not only cause you to crave foods with higher calorie and carbohydrate counts, it will lower your ability to process them through metabolism.

Okay, so now we know that lack of sleep can make you gain weight, but can enough sleep help you to lose additional weight? The fascinating answer is yes: studies show that your body actually burns calories while it sleeps, especially when you sleep for more than 7 hours per night. According to the weight-loss calculator at, a 160 pound person will burn an average of 547 calories during an 8 hour period of sleep4. But don’t count on added sleep to help you drop unwanted pounds alone: exercise and a healthy diet are still key essentials to successful weight loss– but having a longer rest will definitely assist your efforts.

Finally, it’s important to understand how to get better sleep. Some suggestions to improve your sleep quality and enhance your night-time calorie burn include the purchase of a memory foam mattress, keeping a set sleep schedule, and turning down the thermostat at night. Memory foam increases blood circulation, which will nourish your heart, lungs and brain, and maximize your body’s capability to burn calories. Maintaining a consistent sleep schedule will hold hunger pangs at bay, and turning down your thermostat will increase calorie burn because the body expends energy in order to preserve its regular temperature. Remember that losing weight and sleeping better go hand-in-hand, so your quality of sleep should improve as you work toward your ideal weight.

By: Michael Hopper

[1] Wise-Blau, Lisa. Forget Cranky. Lack of Sleep May Make You Fat: Link may be hormones that regulate hunger. Nov. 30 2005.

[2] University of Bristol (2004. December 13). Does the Lack of Sleep make You Fat?. Science Daily. Retrieved June 3, 2009.

[3] Easton, John. Lack of Sleep Alters Hormones, Metabolism. The University of Chicago Chronicle. Retrieved June 3, 2009.

[4] Calories Burned Calculator.