It’s summer! The house is abuzz with activity and late nights filled with pool parties, sleepovers and softball games. Unfortunately, there are still only 24 hours in a day and too many Americans regularly burn the midnight oil to fit everything in. The Center for Disease Control (CDC) reports that 40.6 million workers sleep six hours or less a night. This is well under the seven to nine hours the National Sleep Foundation recommends for adults and can wreak havoc on your weight loss goals.
Sabotaging Weight Loss Efforts
Sanjay Patel and Frank Hu reported in the research journal Obesity that there is a direct connection between insufficient sleep and weight gain. As sleep levels decrease, you feel hungrier and have more time and opportunities to eat; increasing the number of calories you eat during the day. Furthermore, sleeping less increases fatigue, thus reducing your motivation to exercise and subsequently decreasing energy expenditure.
Karine Spiegel and associates at the University of Chicago found that insufficient sleep significantly increases feelings of hunger / appetite. They attributed these changes to circulating levels of two hormones, leptin and ghrelin. After two nights with only four hours of sleep, subject’s blood leptin levels decreased by 18 percent while their ghrelin levels increased by 28 percent. Leptin is released by adipose cells and informs the brain about the state of our fat stores. Specifically, high levels of leptin tell the brain that fat stores are sufficient resulting in appetite suppression, while low levels tell the brain that fat stores are shrinking and need to be replaced. On the other hand, ghrelin is released by the stomach in response to a decrease in gastro-intestinal contents and feelings of hunger. It then travels to the brain, thus increasing your appetite. Researchers do not understand the exact cause of these changes. However, numerous studies document that the levels of these two hormones are adversely impacted by sleep loss.
Sleeping Less and Watching More
In the past 40 years, Americans’ sleep amounts have dropped over two hours (from eight hours a night to six and a half). Losing sleep and feeling tired are all too common in today’s world. Unfortunately, as levels of sleep decrease, physical activity levels also decrease among all populations. Two large cross-sectional studies of children found that as sleep levels decrease, television viewing times increase and organized sports participation decrease. Researchers at Harvard University conducting the Nurses’ Health Study follow over 200,000 nurses and report that sleep loss drastically reduces physical activity levels. It’s a telling statistic that as average sleep times are at an all-time low in America, the average weight is at an all-time high.
Maximizing the Restorative Power of Sleep
While we all enjoy sleeping late on weekends, your body appreciates regularity. Try to keep a tight sleep schedule going to bed and waking at the same time seven days a week. Avoid naps if you can, as they disturb sleep patterns and can interfere with nighttime sleep. Stimulants like caffeine and nicotine can wreak havoc with the best sleep schedule. If you use either, limit your consumption (they make it harder to relax and settle into sleep).
In addition, it’s commonly known that alcohol speeds the onset of sleep. Unfortunately, as it’s metabolized, it disrupts your sleep cycle due to its arousal properties. While regular exercise promotes good sleep, vigorous workouts performed late in the day can interfere with your sleep as well (so schedule these workouts as early as possible).
Sleep Advice
We’ve all heard the famous Ben Franklin quote, “Early to bed, early to rise makes a man healthy, wealthy, and wise.” Apparently, Mr. Franklin knew what he was talking about. Maximize the benefits of regular exercise and a good diet by making sure you get plenty of sleep.
Get more of these “Zzzzzzzzz’s” and you’ll lose more of these “Lbs., lbs., lbs., lbs.”
References
1. http://www.cdc.gov/Features/dsSleep/ retrieved June 12, 2012.
2. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6116a2.htm?s_cid=mm6116a2_w retrieved June 12, 2012.
3. Patel SR and Hu FB. Short Sleep Duration and Weight Gain: A Systematic Review. Obesity 2008:16(3):643-653.
4. Spiegel K, Tasali E, Penev P, Van Cauter E. Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Ann Intern Med. 2004;141:846–850.
5. http://www.discoverymedicine.com/Jennifer-B-Hillman/2011/06/17/ghrelin-biology-and-its-role-in-weight-related-disorders/ retrieved June 15, 2012.
6. http://www.sleepfoundation.org/article/ask-the-expert/sleep-hygiene
Mark Kaelin – Mark is an instructor in the biology department at Bellarmine University. He has a Master of Science in exercise physiology from the University of Louisville and is a certified strength-and-conditioning specialist with the National Strength and Conditioning Association. Mark has been writing since 2001, with work appearing in both consumer and research journals.