One of the most comprehensive studies of the potential link between reduced sleep and childhood obesity finds compelling evidence that children who consistently received less than the recommended hours of sleep during infancy and early childhood had increases in both obesity and in adiposity or overall body fat at age 7.
While several studies have found evidence of an association between sleep and obesity in young children, few have examined the effects of constant sleep deprivation across time or used measures other than body mass index (BMI), which determines obesity based solely on height and weight. The current study analyzed data from Project Viva, a long-term investigation of the health impacts of several factors during pregnancy and after birth. Information used in this study was gathered from mothers at in-person interviews when their children were around 6 months, 3 years and 7 years old, and from questionnaires completed when the children were ages 1, 2, 4, 5 and 6.
Overall, children with the lowest sleep scores had the highest levels of all body measurements reflecting obesity and adiposity, including abdominal fat which is considered to be particularly hazardous. The association was consistent at all ages, indicting there was no critical period for the interaction between sleep and weight. Lower sleep scores were more common in homes with lower incomes, less maternal education and among racial and ethnic minorities; but the association between sleep and obesity/adiposity was not changed by adjusting for those and other factors.