Sleep duration has been linked to obesity. Most of the research on sleep and obesity has focused on sleep duration and quality. Cross sectional (Kripke DF, 2002; Yu Y., 2007) and prospective studies (Patel SR, 2006; Hairston KG, 2006; Nishiura C., 2010) have found associations between short sleep duration and increased risk for obesity, greater percentage body fat, and weight gain over time.Late sleepers had shorter sleep duration, later sleep onset and sleep offset and meal times. Late sleepers consumed more calories at dinner and after 8:00 pm, had higher fast food, full-calorie soda and lower fruit and vegetable consumption. The researchers found out that higher BMI was associated with shorter sleep duration, later sleep timing, caloric consumption after 8:00 pm, and fast food meals. There is associations between short sleep duration and increased risk for obesity, greater percentage body fat, and weight gain over time. Several recent studies using dietary assessments have reported associations between short sleep duration and increased energy intake, particularly from fats; In categorical analyses, late sleepers consumed on average 248 more calories per day than normal sleepers, with the majority of the excess calories occurring at dinner and after 8:00 pm. In addition to all meal and snack times occurring at a later clock time in late sleepers, there were also differences in the duration between meals and sleep. In the late sleepers, there was a shorter duration between breakfast and lunch and a longer duration between their last reported meal or snack, and sleep onset. It is unclear whether these differences are related to misalignment of their appetite or other physiological rhythms with social meal times, but it does indicate that there are alterations in the meal patterns of late sleepers compared with normal sleepers. Besides the difference in meal timing and caloric intake, late sleepers reported poorer food choices including nearly half the servings of fruits and vegetables, twice the fast foods and twice the full-calorie sodas as normal sleepers. These findings are important given the role of diet quality in weight regulation. For example, multiple observational and intervention studies support that increasing high fiber and low calorie foods is a useful strategy in weight management (Rolls BJ, 2004;Tohill BC, 2004).