The journal Sleep [Sleep. 2012May1;35(5):597-603.] of the American Academy of Sleep Medicine recently published a study that suggests that adequate sleep may help combat the congenital tendency to obesity. The study shows that adequate sleep may increase the chances of weight loss success. Nathaniel Watson, a neurologist at the University of Washington Medical Sleep Center in Seattle, who led the study, said, “The less sleep you get, the more genes affect your weight, and the more sleep you get, the fewer genes affect your weight.” Past studies have looked at the association between sleep and weight, but this study looks at it from a genetic perspective. Watson and his team analyzed 604 pairs of identical twins and 484 pairs of fraternal twins for height, weight and sleep duration. The results found that although each person’s sleep habits vary, some clues can still be found. In the study, less than 7 hours of sleep per night was considered insufficient, 7 to 8.9 hours was considered normal, and 9 hours or more was considered too much. Statistically, the average age of those surveyed was about 37 years old, and the average amount of sleep per night was 7.2 hours. The study found that the longer people sleep at night, the lower the body mass index (BMI) than people who sleep less. Watson pointed out that people who sleep less increase the genetic risk of having a higher BMI. While genetic factors in weight change accounted for only 32 percent of twins who slept an average of nine hours, those who slept less than seven hours were up to 70 percent, and those who slept seven to nine hours were 60 percent. Factors including the environment can also affect BMI. Watson noted that both the need for sleep and BMI have genetic characteristics. Philadelphia University sleep expert Jodi Mindell (Jodi Mindell) said the new findings again illustrate the importance of getting enough sleep each night, she said: “If you want to lose weight, adequate sleep can give you a chance of success.”