Lack of sleep may contribute to weight gain
Wednesday, May 23, 2018
Q: I have seen several articles in health magazines about the role of sleep in weight control. Can you tell us about it? — D.M., Greenville
A: We first started hearing about the connection between sleep and weight management about 10 years ago. Scientists now have pretty good information. Catherine Thriveni, a Brody medical student, volunteered to answer your question and titled her piece “Snooze to Lose…but not too much” (snoozing that is). Here is what Catherine wants to share.
It’s well-known fact that a healthy diet and regular physical activity are two keys to weight management. But what if there is another factor affecting the number on the scale? Researchers suggest that a good night’s sleep could be important to your achieving and maintaining a healthy weight.
Although the exact mechanisms of sleep’s effect on the body remain mysterious, one thing doctors can agree on is sleep’s positive effect on health. Sleep is key for learning and memory functions. It helps you think clearly and focus better. It reduces stress and helps regulate your mood. It also helps your immune system, your body’s defense against illness and infection. Getting the right amount of sleep reduces your risk for high blood pressure and heart disease.
But how does it affect your weight? There are several studies that link lack of sleep with weight gain. One of the studies followed nearly 70,000 women over 16 years. They found that one in three of the women who slept five hours a night was more likely to gain a large amount of weight (about 33 pounds) than those who slept seven hours a night. Another study showed that the risk of developing obesity was about those same odds — one in three — for those who slept five-seven hours per night rather than seven-eight hours per night.
There are several possible reasons for weight gain in people who sleep less. We know that lack of sleep increases levels of the hormone ghrelin, which makes us hungry. It also decreases levels of the hormone leptin, which tells the brain we’re full. So, if you don’t get enough sleep, it’s likely you feel hungry and might seek out high-calorie foods. One study I read found sleep-deprived adults ate 300 calories more than they did on the days they were well-rested. Another possible reason is that people without enough sleep feel too tired to be physically active. Not sleeping enough can also lower your metabolism and increase your body’s production of insulin — both of which can lead to weight gain and possibly type 2 diabetes.
Being overweight also can cause sleep problems. A person with obesity has a high risk for developing sleep apnea, a medical condition where a person briefly and repeatedly stops breathing during sleep. This can make the person feel sleepy and fatigued throughout the day, and it also increases their risk for developing high blood pressure, heart disease, memory problems, and mood disturbances. If you have obesity and you feel tired all the time, you might talk with your doctor about how to lose weight and whether or not you need a CPAP machine to help you sleep in the meantime.
Fortunately, getting a full night’s sleep can help you burn more calories. One study showed that resting energy expenditure—the number of calories burned when you’re not moving—was a little bit higher in normal sleepers. Well-rested folks also burn more calories after a meal when compared to their sleepy counterparts. A regular sleep schedule also stops late-night snacking. One study showed that sleep-restricted subjects gained more weight than well-rested individuals, mostly because they ate about 550 calories between 11 p.m. and 4 a.m. In addition to helping you shed pounds, sleep helps you burn fat. One study looked at individuals who ate the same number of calories but slept eight and a half hours per night versus five and a half hours. While both groups lost about 6 ½ pounds, those who were well-rested lost mostly fat, while those sleep-deprived lost more muscle.
The bottom line is that most adults need about seven-nine hours of sleep per night to be rested. If you don’t get that amount, try to go to sleep and wake up about the same time each day. Avoid caffeine four to six hours before bedtime and try not to nap during the day. Get 30 minutes of physical activity every day but not within two hours before sleep. Also turn off all electronic devices one hour before bedtime, don’t have a TV in your bedroom, and try reading or relaxation techniques.
The studies I read were about adults, but kids need sleep to grow and attain a healthy weight, too. A good night’s sleep is one health supplement everyone should use.
Professor emeritus Kathy Kolasa, a registered dietitian nutritionist and Ph.D., is an Affiliate Professor in the Brody School of Medicine at ECU. Contact her at firstname.lastname@example.org.