How Poor Sleep Can Lead to Weight Gain and Type 2 Diabetes

Jan 06, 2019


You Will Learn

  • What hormones are involved in sleep and blood sugar regulation?
  • What are the effects of sleep deprivation on these hormones?
  • What are 3 action steps to get better sleep?  


Sleep and Hormones  

Lack of quality sleep can contribute to weight gain and type 2 diabetes due to hormonal responses to sleep deprivation.4  

In this article, I will break down the major hormones affected when you are sleep deprived, and how they can contribute to weight gain and type 2 diabetes.  


What is a Hormone?  

Think of a hormone as a messenger in your body. Various hormones deliver different messages all around your body to keep your systems running smoothly.  

There are many hormones at play all of the time in your body.  

For this article I am keeping it as simple as possible. I will only talk about Ghrelin, Leptin, Human Growth Hormone, and Cortisol as these are the major hormones affected by sleep deprivation.  

They have other roles in the body, but I will only discuss their roles related to blood sugar and appetite regulation.  



Ghrelin is termed the “hunger hormone” because it stimulates appetite and food intake, especially for calorie-dense foods with a high carbohydrate content. Ghrelin also promotes fat storage.5  



Think of leptin as having the opposite effect of ghrelin.  

Leptin is the hormone that tells you to stop eating. It is responsible for regulating how much body fat you have.  

The longer your body is at a certain weight, the more your body wants to stay at that weight.  

Leptin is one of the reasons why losing weight and keeping it off is so hard.  

When you lose body fat, leptin levels fall so that your appetite is stimulated until the fat mass is recovered.  

By contrast, when fat mass increases, so do leptin levels and appetite is suppressed until weight loss occurs. In this way leptin regulates energy intake and fat stores so that weight is maintained within a relatively narrow range.2,3,5  


Human Growth Hormone  

Human Growth Hormone, also known as HGH, is released by the brain into the bloodstream during deep sleep, and plays a primary role in repairing and building our bone and muscle during sleep.  

HGH production decreases with age. Sleep deprivation or disruption also suppresses normal HGH production.  

Both normal age-related reduction in HGH levels, as well as that caused by lack of sleep, cause side effects such as weight gain, lowered cognitive and physical performance, and reduced muscle mass.  

Insulin and HGH are counterparts. The higher your insulin levels, the lower your HGH levels. High blood sugar inhibits your HGH production, so avoiding foods that will raise your blood sugar before bed will allow HGH to work properly to restore your body while you rest.6  



Cortisol is known as your “stress hormone” because it helps fuel your body’s “fight-or-flight” response in a crisis.  

Under stressful conditions, cortisol provides the body with glucose by turning protein into glucose for energy. This energy can help an individual fight or flee a stressor. However, chronically elevated cortisol consistently produces glucose, leading to increased blood sugar levels.  

Insulin is the key to “unlocking” your cells so that glucose can move out of your bloodstream and into your cells. Cortisol blunts the effect of insulin, essentially making your cells insulin-resistant, so more insulin is needed to have the same effect.

Over time, the pancreas struggles to keep up with the high demand for insulin, and blood glucose remain high.  

When cells are not getting the energy they need, your body thinks it is hungry even when there is plenty of fuel available, just unable to get into your cells. This can lead to overeating.  

Eventually this unused glucose is stored as body fat. Specifically, cortisol tends to increase visceral fat storage, which in and of itself increases your risk for developing type 2 diabetes.1


Bottom Line  

Disrupted sleep alters how your body processes sugar, making you more likely to have high blood sugar, high insulin levels, and gain weight.  


Action Items  

  • If you are not getting 6-8 hours of restful sleep per night, there are a lot of things to try. Try cutting back on added sugar and see if you feel more rested.
  • Limit your caffeine intake, especially after noon. 
  • Limit screen time before bed. The blue light in electronic screens has been shown to lower melatonin levels. Melatonin is the hormone that makes you sleepy. Not only that but scrolling through feeds can get your mind racing when it's time to calm down.  




1. Aaronson, D. Cortisol — Its Role in Stress, Inflammation, and Indications for Diet Therapy. Today’s Dietitian. 11 No. 11 P. 38.

2. Oswal A, Yeo G. Leptin and the Control of Body Weight: A Review of Its Diverse Central Targets, Signaling Mechanisms, and Role in the Pathogenesis of Obesity. Obesity. 2010;18:221-9.

3. Pejovic S, Vgontzas AN, Basta M, Tsaoussoglou M, Zoumakis E, Vgontzas A, Bixler EO, Chrousos GP. Leptin and hunger levels in young healthy adults after one night of sleep loss. J Sleep Res. 2010;19:552–558. doi: 10.1111/j.1365-2869.2010.00844.x.

4. Sanjay R. Patel, Atul Malhotra, David P. White, Daniel J. Gottlieb, Frank B. Hu; Association between Reduced Sleep and Weight Gain in Women, American Journal of Epidemiology, Volume 164, Issue 10, 15 November 2006, Pages 947–954,

5. 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; 141:846-50.

6. Utiger, R. Growth Hormone. Encyclopedia Britannica. April 04, 2018.

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