By Irene Hayton

If you’re one of those people who are struggling to lose weight, even though you’re exercising regularly and eating healthy, you may need to make some changes to your sleep habits. Many people are unaware of the correlation between their weight and the quality and amount of sleep they’re getting. Recent studies have shown that inadequate or insufficient sleep affects a number of hormones in your body which can play a role in gaining body fat, as well as contribute to other health issues.

Melatonin and growth hormone are what Dr. Matsen refers to as your body’s repair crews which do the majority of their work while your body is asleep at night. Melatonin is a hormone that’s responsible for promoting sleep. It’s released when you’re exposed to darkness, causing your body temperature to drop and making you feel drowsy. Melatonin gradually shuts down your adrenal glands and it’s also a powerful antioxidant, neutralizing deadly free radicals in the central nervous system and the intestinal tract. Staying up late watching TV or surfing the internet is counterproductive to getting a good night’s sleep. Besides emitting light, TVs and computers also emit electromagnetic energy, both of which negatively affect your production of melatonin. To help improve the quality of your sleep and your overall health, avoid watching TV or using your computer for a couple of hours before bed so as not to disrupt the production of this important hormone.

Growth hormone, as its name implies, is responsible for stimulating growth in children and adolescents but it also has many other effects on the body. Among other things, it improves bone density and plays an important role in the metabolism of carbohydrates, fats and proteins: it promotes glucose synthesis in the liver, aids in the breakdown of fat and increases protein synthesis (and helps build muscle). Your body releases the most growth hormone while you sleep, especially during deep sleep.

Then there’s the stress hormone, cortisol, which is released by your adrenal glands. Insufficient sleep can lead to elevated cortisol levels, which increases your appetite and elevates your blood sugar and insulin levels causing your body to store fat, particularly in the abdominal area. Cortisol can also make it difficult to get to sleep and stay asleep. Both melatonin and growth hormone help to reduce the negative effects of cortisol. The adrenal glands recuperate best between 11 pm and 1 am so do them a favour and try to get to bed by 10 or 11 pm. Your body will also thank you if you establish a regular sleep schedule by going to bed and getting up at the same time every day, as much as possible, even on the weekends or your days off.

Two hormones that influence our eating behaviour and are affected by sleep are ghrelin and leptin. Ghrelin is produced in the stomach and is your body’s hunger hormone. It stimulates your appetite, telling your brain that it needs food, and decreases after eating. Research shows that ghrelin may also slow down fat metabolism. Leptin is produced by your fat cells and tells your brain when you’re full and that it’s time to stop eating. When you’re sleep deprived, your levels of ghrelin increase and leptin levels decrease, which can lead to increased cravings for food and lack of satiety—not feeling full. For many of us that can mean eating larger portions and eating more often and still not feeling satisfied. And it can also mean reaching for unhealthy choices such as coffee, chocolate and sugar to give us that energy boost (albeit temporary) that we want when we’re tired.

You can see how deep, restful sleep may play a role in achieving weight/fat loss—along with healthy eating and proper exercise, of course. So if you snooze well, you may lose the unwanted pounds. For more info on sleep and tips to get a good night’s sleep, see the following articles on the Doctor’s Monthly Message page:

  • February 2005 “Jeepers Creepers, We Need to Be Good Sleepers”
  • January 2005 “Sleep Apnea”
  • August 2007 “Sleeping Well When You’re Away From Home”
  • March 2006 “Interrupted Sleep”
  • June 2004 “Lavender Dreams”