Sleep is an essential part of a healthy lifestyle, especially when you’re trying to lose weight. A good night’s sleep repairs cellular damage, improves mental focus, boosts immunity and helps facilitate weight loss. Together with diet and exercise, sleep provides the foundation of your long-term health and wellness—it can prevent heart disease, promote healing and prevent excess weight gain.
Just like diet affects quality of sleep, how much you sleep impacts your diet.
Sleep-Deprivation Stimulates Appetite
When you’re not getting adequate sleep, you’re more likely to overeat and snack. This is because sleep affects two critical hormones that regulate hunger: ghrelin and leptin. Ghrelin, which is produced by cells within the digestive tract, signals the brain that you’re hungry, increases consumption and promotes fat storage. Leptin, often referred to as the “satiety hormone,” inhibits hunger by signaling feelings of fullness and helps regulate energy balance. While sleeping, your ghrelin levels are low and leptin levels are high. Sleep deprivation causes these hormone levels to move in the opposite direction.
Hormone Fun Fact: Because Ghrelin levels are low and Leptin levels are high while sleeping, most people don’t find themselves to be hungry in the morning as these hormone levels persist into morning. Second, these hormone levels are thought to have assisted with survival eons ago, during the winter, when daylight is shorter. Sleeping longer hours helps stave off hunger during winter-time when food was scarcer.
You Crave Fattening, Unhealthy Foods
Studies show that when gherlin levels are high and leptin levels are low, we crave high-calorie foods with too much sugar, simple carbs and unhealthy fats. On top of that, when you’re tired, it’s more difficult to resist unhealthy foods—your mind is less likely to register the consequences of these foods on your diet. Sleep-deprived people are also more likely to eat junk food and consume a greater number of calories after 8 pm.
Why do you snack so much at night? People commonly complain about having less control over hunger and cravings at night. Our hunger increases at night due to our natural biorhythm (circadian rhythm). The mechanism thru which this happens is not well known. The fatigued brain has less resistance against cravings and hunger. This is why staying up late leads to more snacking. This is also why being sleep deprived leads to the same.
Lack of sleep also causes a spike in cortisol, the hormone that stimulates insulin release and the metabolism of fat and carbs. When its secretion is disrupted, this signals your body to store energy and fat, essentially slowing down your metabolism. You’ll burn less calories and your blood sugar levels will go awry, which wreaks havoc on hunger. Studies show that cortisol also causes fat to store centrally around the organs—specifically the abdomen—resulting in stubborn belly fat.
The bottom line—lack of sleep negatively impacts weight loss and can even cause weight gain. To manage hunger and prevent unhealthy eating, strive to set a consistent, healthy bedtime schedule. According to the National Sleep Foundation, the average adult needs to sleep between seven and nine hours per night. Plan to go to bed and wake up at the same time every night with a goal of getting adequate, quality sleep.