That’s what a just-published study suggests, and whether it’s actually true or not, it bears a closer look.

“Social jet lag”?

This is just the difference in our sleep schedules between workdays (for kids that means school days) and non-workdays. Usually it means we sleep later on weekends.

How could social jet lag make people fat?

This latest study, involved 3412 children ages 8-10 years, and found that those having a different sleep schedule on weekends (or non-work/school days) also are more likely to be obese and have metabolic differences associated with obesity, like a higher waist-to-hip ratio and higher body fat percentage.

Interestingly, the kids didn’t get any less sleep on weekends, they just went to bed later — about an hour later – and awakened that much later as well. Average delayed bedtime was about 43 minutes later than during the week, but most of the kids still slept their usual 9 hours (for adults, this is like a fantasy!).

This study can’t determine just WHY these results occurred because it wasn’t longitudinal, just cross-sectional. It’s possible that the higher weight of the late-sleepers is a lifestyle marker: kids who stay up later on weekends might also do more nighttime snacking.

It’s not just kids though. In this study of social jet lag in adults, the authors concluded, “misalignment of sleep timing is associated with metabolic risk factors that predispose to diabetes and atherosclerotic cardiovascular disease.” Even if we still manage to slog through the next day, but in the long run this practice may be doing more harm to our bodies and our weight than what we put into our mouths.

Re-setting our circadian clocks is totally doable

You or your kids may not be “morning people” but so much of their – and our – days, at least during the week, requires us to be awake and at our best in the morning.  Give yourself and the family some time to get this all done, but the steps are totally worth it, for better sleep, better functioning during the day, and maybe even better weight and health.

Here’s how to start:

Shut it down early. Even if you and your kids swear you’re not tired, cut the noise from TV, videos, and screens at least an hour before bedtime. Music is fine, but not stuff that makes you want to get up and dance.
• Lose the “blues” – blue light, from devices like cell phone and computer screens, but also from the TV and even the power lights from the routers and such, really interfere with sleep because they prevent you from winding down.
• No power napping in the afternoon. If your kids often need naps after school, they need more sleep at night, period.
Decaffeinate after noontime. The kids, too.  That means skipping colas, iced tea, and any of those sweet (and too caloric) coffee drinks that many teens (and adults) like.
Move more, sleep better. Daily, regular physical activity really helps re-set your sleep cycle. You’re more likely to want to wind down if you’ve been active during the day. It’s just healthy lifestyle practice anyway, and better sleep is another benefit.
CLOSE THE KITCHEN! Your digestive system has to wind down, too, and it needs to do so a good two hours before bedtime. You’ll get deeper, more satisfying sleep.