Amount of Sleep Impacts Weight Gain Over Time

Harvard School of Public Health and Brigham and Women's Hospital conducted a study that identified the factors that help prevent weight gain. They are: food choices, getting enough sleep, watching less TV, and getting enough exercise. Today I want to shed some light on how sleep impacts weight gain. Many of my patients are surprised to learn that sleep can have an effect on their weight. One way that weight and sleep are connected has to do with the time that you eat your last meal of the day and the time you go to sleep. It takes your digestive tract about three to four hours to digest your food. If you are eating dinner late and going to sleep soon after you eat you are creating an equation for weight gain. Think of it like this: food is our body’s fuel; if you eat and then go to sleep, the digestive system provides all this fuel to you to use but you are sleeping. The body then decides to store the fuel as fat and your weight goes up. The simple solution is to finish eating and snacking three to four hours before you go to bed.

Another way that sleep impacts weight is through affecting the hormones leptin and ghrelin. Leptin and ghrelin are hormones that regulate feelings of fullness (satiety) or wanting to eat (hunger). Gherlin stimulates hunger and leptin stimulates satiety. When high levels of leptin are circulating in the blood it signals to the brain that we feel full. When we have low levels of leptin circulating then we feel hungry and have signals to eat. Research has showed that when people suffer from too little sleep their leptin levels are lower, resulting increase in appetite. Gherlin levels end up rising, which causes over eating.

In 2008, the National Health and Nutrition Examination Survey conducted a questionnaire that found a short sleep duration was found in 40 percent of the participants between the ages of 40-59 years. This short sleep duration could be a contributing factor in people’s ability to lose weight. I want to point out that there is a difference between the amount of sleep you need to get by in a day to function and adequate sleep.

Many patients report that they need only 4-5 hours of sleep to function each day but this is different from adequate sleep for your body--for adults the amount is generally 7- 9 hours nightly--to maintain health over time. Sleep is important to create a healthy life and maintaining appropriate weight. And it's just another example how small behavioral changes can make a big difference in your weight.

Live Vibrantly, Dr. Dae