sciencehabit writes "A new study suggests that, by disrupting your body's normal rhythms, your alarm clock could be making you overweight. The study concerns a phenomenon called 'social jetlag.' That's the extent to which our natural sleep patterns are out of synch with our school or work schedules. When we wake up earlier than we're supposed to — or spend all weekend sleeping in and then get up at 6 am on Monday — it makes our body feel like it's spending the weekend in one time zone and the week in another. For people who are already on the heavy side, greater social jet lag corresponds to greater body weight."