Sleep plays a powerful role on our overall health as well as our tendency to gain excess weight. Sleep duration is linked to gains in abdominal fat even after accounting for other factors that could influence weight, such as calories consumed and exercise habits. This means that if you do not take your sleep needs seriously, you could unknowingly be sabotaging your weight.
The link between sleep and weight gain is valid whether you sleep too little or too much. Sleeping less than five hours — or more than nine hours — a night appears to increase the likelihood of weight gain. In one study, recurrent sleep deprivation in men increased their preferences for high-calorie foods and their overall calorie intake. In another study, women who slept less than six hours a night or more than nine hours were more likely to gain 11 pounds (5 kilograms) compared with women who slept seven hours a night. Other studies have found similar patterns in children and adolescents.
A science based explanation might be that sleep duration affects hormones regulating hunger — ghrelin and leptin — and stimulates the appetite. Another contributing factor might be that lack of sleep leads to fatigue and results in less physical activity. Therefore, even if you lead a healthy active life you must also get a good night’s sleep.