There are many studies that suggest a strong correlation between sleep and weight. An individual that sleeps more, weighs less. In fact, findings have shown the relationship between sleep and weight is present regardless of gender or age. The majority of these studies, however, primarily focus on the correlation between the two variables and did not find the exact cause of the correlation between sleep and weight.
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There are several factors that could cause a person to weigh less with more sleep, or weigh more with less sleep. One factor in particular, appetite control, sheds more clarity to the relationship between sleep and weight.
Leptin and Ghrelin
According to a study conducted in University of Chicago, “short sleep duration in young, healthy men is associated with decreased leptin levels, increased ghrelin levels, and increased hunger and appetite.”  Leptin and Ghrelin often times function as satiety regulatory hormones meaning they control a person’s appetite. Leptin functions as an appetite-suppressant. Leptin levels increase when a person is full and signals the brain it has had enough to eat. Notably, this “fullness” hormone makes it easier for individuals to resist foods high in calories. This explains why drop in leptin levels was associated with an observed 33 to 45 percent increase in the participants’ desire for calorie-dense food with high carbohydrate content. Ghrelin is an appetite-inducing hormone. In contrast to Leptin, circulating levels of Ghrelin are highest right before a meal and lowest right after.
Sleep Influences Hunger
The findings in this study strongly suggest that the weight gain correlated to less sleep is not directly caused by lack of sleep, but by the increased desire for food as dictated by the participant’s altered hormone levels. Increased levels of Ghrelin, however, is not only associated with increased hunger, but also has been linked to depression and anxiety disorders, so people who have a tendency to “emotional eat” will most likely feel a stronger urge than a non-emotional eater.
Are you truly sleeping?
There is an overwhelming amount of evidence tying less sleep to increased weight. Of course, there are outliers who would associate less sleep with decreased weight. However, I believe its a short-lived weight-loss. Less sleep means less energy to participate in energetic activities, which will lead to a sedentary lifestyle – a condition strongly linked to being overweight and obesity.
Additionally, more sleep does not necessarily mean you are actually getting more sleep. People with sleeping disorders such as sleep apnea, insomnia, restless leg syndrome, sleep walking, and other psuedo-disorders that is a result of a combination of issues, may have trouble reaping the full benefits of sleep if any. Better sleeping habits including refraining from eating large amounts of food when near bed time, sleeping in a quiet, clean and comfortable room, having a regular sleep schedule, etc. may help alleviate the symptoms of these conditions. As precaution, it is best to contact your doctor if you think your condition warrants further examination.
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If you are trying to lose weight or simply trying to stay healthy, make sure to include a good night’s sleep in your work out regime. Nothing beats a high quality full night rest. It has a multitude of health benefits, pertinently, it makes sticking to a low-calorie diet easier as it prevents the artificial increase in hunger levels.
1. Speigel, Karine, PhD, Esra Tasali, MD, and Plamen Penev, PhD. “Brief Communication: Sleep Curtailment in Healthy Young Men Is Associated with Decreased Leptin Levels, Elevated Ghrelin Levels, and Increased Hunger and Appetite.” Harvard. Ann Intern Med, n.d. Web.