Late bedtime after 22.00 hours affects daily weight gain in 4‐month‐old infants

This study examined the relation between the bedtime of 4-month-old infants and their daily weight gain, using health check-up data and a questionnaire. The infants, totalling 155 in number, were divided into a late group (109 infants; LG) whose mothers had taken them to bed after 22.00 hours and a control group (46 infants; CG) whose bedtime was earlier than 22.00 hours. The daily weight gain was significantly lower in the LG than the CG and this was related to bedtime by multiple regression analysis.