Washington: Scientists have already stated that sleeping for less than eight hours a day is harmful for people. A research now indicates that if a person is deprived of sleep for more than eight hours a night, it may cause weight gain in teenagers.
"Sleep is food for the brain. When teens do not get enough sleep, they fall asleep in class, struggle to concentrate, look and feel stressed, get sick more often, and do not meet their obligations due to tiredness," said study author Lata Casturi of the Baylor College of Medicine.
"Teens who sleep less than eight hours may also consume more calories than those who sleep more than eight hours. Therefore, they have a higher risk for obesity and associated health problems, including high blood pressure, heart disease, and stroke," a college statement quoted Casturi as saying.
Casturi and colleagues, including co-author Anita Rao, presently a 10th grader at Dawson High School in Pearland, Texas, surveyed 255 teens (108 boys and 147 girls) in high school to obtain self-reported measures of height and weight and both weekday and weekend quantity of sleep.
How does lack of sleep really affect weight gain? According to researchers, the hormones leptin and ghrelin work in a "checks and balances" system to control feelings of hunger and fullness.
Ghrelin, which is produced in the gastrointentinal tract, stimulates appetite, while leptin, produced in fat cells, sends a signal to the brain when a person is full.
"When you don't get enough sleep, it drives leptin levels down, which means you don't feel as satisfied after you eat. Lack of sleep also causes ghrelin levels to rise, which means your appetite is stimulated, so you want more food," said co-author Radha Rao, DeBakey VA Medical Centre, Houston, Texas.
"The two factors combined can set the stage for overeating, which, in turn, may lead to weight gain."
These findings were presented at CHEST 2011, the 77th annual meeting of the American College of Chest Physicians (ACCP).