Scientists have been looking into the association between sleep deprivation and weight gain in both adults and children.

One study concluded that people who slept less than five hours per night were 73 percent more likely to experience weight gain than those getting seven to nine nightly hours.

Other findings:

Research of sleep deprivation in men found that it increased their desire for foods higher in calories, along with overall calorie intake. A study of women who consistently slept less than six hours or more than nine hours were more likely to gain 11 pounds, compared with women who slept seven hours a night. Similar findings were seen in children and adolescents.

Along with increased daytime fatigue that contributes to lesser amounts of physical activity, the amount of sleep we get influences the hormones insulin, glucose and cortisol, as well as leptin and ghrelin, two hormones that are responsible for regulating hunger. Leptin signals the brain to stop eating, and people who are sleep-deprived have less of this hormone. Ghrelin’s job is to signal you to eat. It has been shown that those who are sleep-deprived have more of this hormone. The combination of more ghrelin and less leptin promotes weight gain.

How efficient leptin is at sending these signals is still being studied. The body’s production rate of leptin, its resistance to it, or a combination of these factors, can all influence eating behaviors and amount of calories burned. Scientists hope to uncover important clues into what effect leptin has not only on obesity but also other conditions such as diabetes.

Also being studied are how everyday habits, environment and genetic predispositions affect leptin’s signaling abilities. After a person has dieted, for example, it appears as if levels of this hormone decline, suggesting that less leptin is being produced and available to signal the brain. This reduction may contribute to increased hunger and slower metabolism and might help explain why after dieting many individuals experience significant weight gain. If found to be true, then leptin therapy may help people maintain weight loss after dieting. The amount of leptin in the bloodstream correlates to percentage of body fat and body mass index (BMI). Generally, greater body mass and percentage of fat equate to higher leptin levels, although this can vary from person to person.

With sleep deprivation comes an increased urge to grab a sugary treat or extra cup of coffee for a quick energy boost. Although this may seem like a good idea at the time, the effect is short-lived, with the inevidable “crash” soon following. Extra food and beverages add up to hundreds of extra calories each day, making it even harder to lose weight.