The verdict is in on the relationship between sleep and weight: Research indicates a connection between how much people sleep and how much they weigh. In general, people who don’t get enough sleep tend to weigh more than people who do get enough sleep.

The harmful effects of sleep deprivation range from hormonal imbalances that can lead to overeating, to reduced metabolic rate, to simply being too tired to exercise. So, conversely, there is also a relationship between good sleep and weight loss, as well as better overall health.

A startling study

The Nurses’ Health Study followed about 60,000 women over the course of 16 years, tracking sleep habits, weight, diet, and several other lifestyle factors. At the outset of the study, all of the women were healthy and none were obese. Here’s what the researchers found 16 years later at the end of the study:

  • The women who slept only five hours or less each night had a 15% higher risk of becoming obese than the women who slept at least seven hours per night.
  • The women who slept less also had a 30% greater risk of gaining 30 pounds during the course of the study than the women who got seven hours of sleep.

The researchers attributed this greater risk of weight gain and obesity for the sleep-deprived women chiefly to:

  • Being too tired to exercise and thus “decreasing the ‘calories burned side’ of the weight-change equation”; and
  • Disruption in “the balance of key hormones that control appetite”

But there’s likely a lot more to it than that.

Sleep and appetite

As in the study mentioned above, sleep-deprived people experienced increased appetite owing to the almost inevitable hormonal imbalances. It’s generally thought that this increase in appetite occurs because lack of sleep impacts ghrelin and leptin, the two important hunger hormones.

Released in the stomach, ghrelin tells your brain when you’re hungry. So when working properly, ghrelin levels are high right before you eat and much lower after you eat. Lack of sleep, however, can keep ghrelin at abnormally high levels so that you feel hungrier more often.

Leptin, which is released from fat cells, serves to suppress hunger and tells your brain that you are full. But without adequate sleep, you produce less leptin, and your appetite increases.


The relationship between sleep and weight loss also includes the fact that insufficient sleep affects your ability to make healthy eating choices – actually altering brain function to a degree.

Sleep deprivation decreases activity in the brain’s frontal lobe, the part of the brain that controls decision making and self-control. When you don’t get enough sleep, it’s simply harder for you to resist eating too many potato chips or too much ice cream. In addition, research has shown that lack of sleep increases your craving for high-calorie foods full of carbs and fats.

Metabolism and muscle

The amount of sleep you get also affects your basal (or resting) metabolic rate, which determines how many calories your body burns while at rest. Lack of sleep can lower your metabolism so that you burn fewer calories and more easily gain weight. One study found that a single night of sleep deprivation resulted in a marked decrease in metabolic rate and concluded that “one night of sleep deprivation acutely reduces energy expenditure in healthy men.”

Further, poor sleep can cause you to lose muscle mass, which is critical for a higher metabolic rate. For example, a loss of about 20 pounds in muscle can result in a metabolic rate lowered enough that you burn 100 fewer calories each day. In one study, overweight adults were put on a moderately calorie-restricted diet for 14 days, with one group getting 8.5 hours of sleep and a second group getting only 5.5 hours sleep each night. The group getting only 5.5 hours of sleep showed more weight loss from muscle and less from fat than those in the group who got more sleep.

Sleep and insulin resistance

Good sleep can help keep diabetes away, but poor sleep can lead to insulin resistance, the first step toward diabetes. Insulin is the hormone that aids in moving sugar from your bloodstream into your body’s cells so that it can be used as energy. When your cells become resistant to insulin, more of the sugar stays in your bloodstream, so your pancreas produces even more insulin to compensate. The result is that the extra insulin makes you hungrier, your body stores more calories as fat, and, if this goes on long enough, you develop type 2 diabetes.

And lack of sleep can play a part in all this. For example, one study allowed 11 men just four hours of sleep for six consecutive nights. At the end of this period, the ability of their bodies to lower blood sugar had decreased 40%.

Best kind of sleep for weight loss

So, contrary to popular thought, weight loss involves more than taking in fewer calories and exercising. There is now an undeniable, research-backed connection between sleep and weight loss (or weight gain). But sheer volume isn’t the only thing that matters when it comes to sleep. The kind and quality of sleep also count.

The best kind of sleep for health and weight loss is what is known as slow-wave (or non-REM) sleep, because it has the most beneficial effect on the hunger hormones ghrelin and leptin. Also, getting fragmented or intermittent sleep is just as bad as not sleeping enough. Without adequate deep, restful sleep, your hunger hormones will be activated, which can lead to weight gain.

To get more restful sleep, set a bedtime schedule and stick to it. Try to go to bed and get up at the same time every day — even on weekends. Put away or turn off smartphones and other devices a couple of hours before bedtime, as the blue light emitted by these devices can keep you awake. Keep the bedroom cool and dark and invest in some good-quality sheets to make your sleep space more comfortable.

Addressing sleep and weight loss

At Quest Weight Loss, we want you to achieve your weight-loss goals, but we also emphasize overall health and general well being. And that includes better sleep, hormonal balance, and metabolic efficiency.

Our personalized plans focus first on safety, efficacy, and health benefits, backed by comprehensive testing that allows us to get to the root of your weight-loss challenges. Your custom-tailored plan will address hormonal imbalances, metabolic disturbances, or other health issues that may be interfering with your body’s ability to shed excess weight.

If you’re ready to take the first step towards achieving lasting weight loss and better health, contact us today for a free consultation!