The sleep allows many psychological processes, such as immune system activity, body metabolism and hormonal balance, emotional and mental health, learning, mnemonic processes. The lack of sleep could undermine mental and physical purposes, causing an alteration in cognitive functions or metabolic disorders. In our study, we have examined the irregular sleep effects with the overweight and obesity risk in children and adults.The sample was composed of 199 subjects, of which 71 adults, (29 males and 42 females), and 128 children (73 males and 55 females). We have measured the weight and height with standard techniques; we also have measured the body mass index dividing the weight in kg with the height square expressed in meters (kg/m). Subjects were divided into underweight, normal weight, overweight, and obese. Were administered some questionnaires to measure the quantity and quality of sleep, and eating habits and individual consumption of food.Analysis of demographic variables not showed significant differences between male and female groups but highlighted a significant trend differences in normal-weight score. The clinical condition has a substantial impact on body mass index score and sleep hours were significant predictor on this.Quantity and quality sleep can also represent a risk factor of overweight and obesity, so sufficient sleep is a factor that influence a normal weight. Adults and children that sleep less, have an increase in obesity and overweight risk with dysfunctional eating behaviors, decreased physical activity, and metabolic changes.