If you don't want your kids to slowly become fat, a new study says that you may want to send them to bed earlier than usual. Researchers say that parents shouldn't rush to put their preschoolers to sleep earlier but should definitely focus on maintaining a regular routine when it comes to scheduling meals and bedtimes. The report warns that under current trends, the world will have more than 250 million obese kids by 2030. Late bedtime was one factor that really stood out in the study. They found that children who habitually went to sleep late, defined as past 9 p.m., had a wider waist and higher BMI (body mass index) by the end of the study.