The Missing Ingredient For Weight Loss

By: David Fein, MD
Medical Director

The airwaves and the internet promote an unending stream of miracle weight-loss treatments. From the miracle “science” of glycemic index to jiggling weights that do all the work while you just stand there holding them, we are all searching for a better, easier way to lose weight. And if any of these really worked in the long term there wouldn’t be any overweight people by now.

It turns out that you already have one of the most effective tools for controlling your weight. Virtually every one of us has one. Some of us have more than one. We use it every almost every day. And the more you use it, the easier it may be to control your weight. The problem is: many of us just don’t use it enough.

It’s your pillow.

Researchers have known for years that there is a direct connection between sleep and weight gain. .People who are sleep-deprived tend to gain weight. With a newly published researched, the evidence has become even worse The study, in the Annals of Internal Medicine, shows that people who diet but don’t get enough sleep may lose weight but it is not fat that they are losing.

It seems counter-intuitive at first. We usually associate sleeping more with being inactive and burning fewer calories. We constantly hear that exercise is important to increasing your calorie burn and losing weight. Finding time to exercise is a challenge for many of us in today’s multi-tasking, hectic lifestyle. So our sleep becomes the time bank. If you’re working all day and have no time for physical activity you don’t think about changing your work schedule. You just get up a bit earlier so you can cram in some exercise before work.

The problem is that there appears to be a connection between the amount of your sleep and the levels of many hormones, including the ones that may control appetite. Two hormones seem to be particularly important. They are Ghrelin, which is responsible for feelings of hunger, and Leptin, which tells the brain when it’s time to stop eating.

Sleep deprivation increases the production of Ghrelin and stimulates the appetite. At the same time, it lowers the level of Leptin and makes you feel like you have not had enough to eat. The end result is that when you don’t sleep enough you feel hungry even when you have had enough to eat and shouldn’t be craving more food. These hormones, and others affected by sleep, may also have a role in whether your body burns fat for calories or uses other sources.

A study published in 2005 followed 8,000 adults for several years. Sleeping less than 7 hours per night was correlated with a greater risk of weight gain and obesity. The risk increased for each hour of lost sleep.

In a more recent study published in the Journal of Clinical Nutrition researchers measured the food intake in two groups of men to see if it varied according to their sleep schedule. In one group the study subjects slept for 8 hours and in the other group they slept for only 4 hours per night. When the men slept less they consumed more than 500 extra calories per day compared with their intake after 8 hours of sleep. To put that in perspective, adding 500 calories per day to your diet would be expected to increase your weight by about 50 lbs in just one year. Other studies have not shown such a dramatic effect on weight gain but the trend across the studies is clear. Lack of sleep leads to increased hunger and higher calorie intake.

The latest research adds a new wrinkle to the problem. The researchers followed 10 overweight subjects who were on a calorie-restricted diet. Half the group got about 8 hours of sleep per night and the other half only got about 5 hours per night. All the participants in the study lost weight. The surprise was that the weight loss in the sleep-deprived group turned out to be due to loss of muscle mass, not fat. The weight loss in the people who got more sleep was from fat loss.

Most people assume that when they see their weight go down that they are losing fat. In fact, your bathroom scale does not differentiate between fat loss and muscle loss. Specialized tests to measure body composition are needed to detect the difference. It is possible that the hormonal changes associated with insufficient sleep cause the body to use muscle as a calorie source instead of fat. This study only followed a small number of subjects for a very short period of time. So these results should be considered preliminary. If subsequent studies are able to duplicate this result it will have significant implications.

These results don’t mean that you can sleep your way back to your high school weight. But, it does mean that you very likely can make your efforts at controlling your weight more effective and healthier by ensuring that you get sufficient sleep.
Most of use need between 7 to 9 hours of sleep per night. You’re actual need may be more or less than that amount. One way to tell how much sleep you need is to try letting your body sleep as much as it wants for a period of several days, such as when you are on vacation. Eventually, you should find yourself waking up after a consistent number of hours. Once you have determined how much sleep you really need, the next step is to work out a routine that allows you to get that much sleep.

Instead of thinking of your sleep time as your “time bank” from which you can borrow time for other activities, make getting enough sleep as much as priority as eating well and getting exercise if you want to be successful in staying well and keeping your weight under control.