• 1Make Sleep a Priority (VIDEO)
  • 2Why Do We Need Sleep?
  • 3We Sleep in Cycles
  • 4How Much Do We Need?
  • 5Your Inner Clock
  • 6In Your Dreams
  • 7Sleep Helps Your Body Rebuild
  • 8Sleep Helps You Remember
  • 9Sleep Helps You Fight Illness
  • 10Sleep and Your Weight
  • 11Sleep Fights Weight Gain
  • 12Sleep Keeps You Alert
  • 13Sleep Helps Control Stress
  • 14Could You Have Sleep Apnea?
  • 15The Dangers of Sleep Apnea
  • 16Why Kids Need Their Sleep
  • 17Seniors Need Sleep
  • 18Best Bets at Bedtime: Food
  • 19Best Bets at Bedtime: Drink
  • 20Best Bets at Bedtime: Exercise
  • 21Best Bets at Bedtime: Other Activities
  • 22Sleep Gadgets and Gear
CHAPTER 11

Sleep Fights Weight Gain

Your appetite control hormones and metabolism are thrown off balance when you don't get enough sleep.

PART 1

The Appetite Control Hormones

Some factors contributing to the obesity epidemic in the U.S. have been clear for a long time. We don't get enough exercise, and we eat too much unhealthful food. Now, the research is piling up that our poor sleep habits are likely part of the picture, too. Sleep plays a role in appetite regulation, energy use, and weight gain. READ MORE

Your body's natural appetite suppressor is the hormone leptin. It signals your brain that you do not need any more food. Its opposite is the hormone ghrelin, produced in the stomach, which tells your brain that you are hungry and need to eat. During sleep, the body’s production of leptin increases, and production of ghrelin decreases. So when your sleep is interrupted, leptin production is suppressed and ghrelin production is greater. In one study, subjects were allowed to sleep only four hours per night for two nights. Their leptin levels decreased 18 percent, and their ghrelin levels went up 28 percent. When the hunger signals outnumber the satiety signals, you want to eat whether or not your body needs food.

Studies find that the less people sleep, the more likely they are to be overweight, and and to eat foods that are high in calories and carbohydrates. The statistics back up this story. People who report an average total sleep time of 5 or fewer hours a night are much more likely to become obese than people who sleep 7–8 hours a night. LESS
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PART 2

Controlling Your Blood Sugar

Another hormone that helps control the body's use of energy is insulin. Insulin enables cells to take up energy in the form of glucose from the bloodstream. Evidence is mounting that too little sleep, or regularly interrupted sleep, can result in less efficient uptake of glucose. One study found that healthy young men who slept only 4 hours per night for one week had the same levels of insulin and blood sugar as people who were developing diabetes, the chronic condition in which insulin's function is seriously impaired. READ MORE

A study of women found that those who slept less than 7 hours a night were more likely to develop diabetes than those who slept between 7 and 8 hours a night. Researchers see a connection between blood glucose and insulin and the slow-wave or deep sleep stage of slumber. LESS
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PART 3

Too Much Sleep?

Getting enough sleep is a good start to keeping your appetite and metabolism in check. But can you get too much sleep? It turns out that you can. It is not a common problem in our sleep-starved society, but it is a serious one. Adults who sleep 10 hours or more per day are at increased risk of diabetes and obesity. READ MORE

Oversleeping can result from depression, stress, side effects from medications and other problems. It is associated with many negative side effects, including headaches and back pain as well as disease risk. If you routinely sleep 9 or more hours per night, tell your doctor about it so you can investigate the root cause and get your sleep cycle back on track. LESS
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