A Randomized Controlled Trial of Sleep Extension to Reduce Overweight and Improve Learning in Prepubescent Children
More2Sleep is a randomized, controlled, parallel trial with two groups (sleep extension vs control) including 300 school-aged children (6-9 years) who are mildly overweight or obese and habitually sleep for ≤ 9 h/night. Data will be collected before and after a 3-month sleep extension intervention, and after a 6-month follow-up (at months 0, 3, and 9). The collection of data is mainly related to the main study. However, some optional examinations will be conducted on a first come, first serve basis, consisting of substudy-I (metabolic mechanisms, n=60) and substudy-II (learning mechanisms, n=150). The primary objective is to assess the effects of sleep extension by \ 45 min/night, achieved by going to bed 60-90 min earlier, on adiposity and learning ability in school-aged children who are overweight or obese, and sleep less than recommended for their age.
• Age: 6-9 years old (inclusive range).
• Weight status: modestly overweight or obese (equivalent adult BMI of 25 to 35 kg/m2) defined as a sex-specific BMI Z-score between +1 and +3 (inclusive range) using reference standards from the World Health Organization.
• Sleep duration: sleeping ≤9 h/night on the basis of sleep diaries filled in by the children's parents, based on recommendations by the American Academy of Sleep Medicine and the Sleep Health Foundation.