Sleep: The Surprising Factor in Weight Loss

We typically don’t think of sleep as important when trying to lose weight, but it’s a critical factor.  Our body’s functions and organs are tightly interconnected. There are thousands of chemicals, hormones and signals that talk to each other and drive what processes occur in our body.  They regulate metabolism, cell growth, energy use, inflammation, repair, and so much more.

We are starting to understand that much of this control is driven by a master clock in the hypothalamus.  It operates on a circadian rhythm regulated by light signals. Many of our hormones such as stress hormones, thyroid, and sex hormones operate in a cyclic pattern throughout the day. That’s because each individual cell in our body has an internal clock as well that responds to this master clock.  Together they work to keep our body operating in balance.  

Ever wonder why you get an urge to snack when you are up late?  Not just that, but you also crave foods higher in fat and sugar?  It’s because the hunger hormone produced in the stomach, called ghrelin, rises with lack of sleep, and leptin, the opposite hormone that keeps ghrelin in check and helps you to feel full, falls.  By the way, these two hormones do much more than just affect your appetite. They work to control the energy balance and storage in your body through lots of other mechanisms. It’s a system of checks and balances regulated by the master clock. 

What happens when you stay up late regularly and don’t get enough sleep?  Over time, many adverse health risks may occur—you can gain weight, develop diabetes or prediabetes (one study showed blood sugars rising within one week of less than 6 hours of sleep a night), lower metabolic rate, and elevated lipids.  

There’s also been a lot of research on people who work night shifts long term and how that affects their health.  They are at higher risks for obesity (30% higher risk), diabetes, hypertension, and in women, even breast cancer.         

So how much sleep is enough?  It seems that the ideal amount is between 7-8 hours of sleep, to be exact 7.7 hours a night in one study.  Much higher or lower than this and your BMI will rise.  

Related to this is eating late or eating right before bedtime.  This increases the risk of weight gain as well. Studies were done with identical mice fed identical food, but one set was fed during normal hours and the other set was fed late at night.  Those who were fed at night gained almost 30% more weight.  

Understanding how your body works will help you make changes to benefit your health.  So as you work on getting to a healthier weight, avoid eating late, especially close to bedtime, and aim for 7-8 hours of restful sleep.  This ensures the best conditions for your body to function.