Link Shown Between Poor Sleep, Weight Gain

Once again, a study confirms that too little or too much sleep is bad for you.

This report, published in the medical journal Sleep, shows a link between sleepers who get less than 7 or more than 8 hours of sleep per night and weight gain over time. Getting less sleep increased risk more than getting extra sleep did.

Three Things You Need to Know:

1. This study is higher quality than most--it followed individuals for six years, comparing hours of sleep to changes in body mass index. One problem: The hours of sleep were self-reported, always less reliable than actual measurements.

2. The findings are similar to, if not quite as scary as, a study I reported on in September showing a link between too little or too much sleep and. . .death. That study suggested that the "safest" amount of sleep is around 7 hours.

3. The takeaway: If you're overweight, don't look only at your diet and exercise habits, but your sleep as well. And if you tend to sleep much more or less than 7 to 8 hours nightly, you may be putting yourself at risk of gaining weight--and, if the previous study is accurate, premature death.

All good reasons to check in with a sleep specialist if you fall too far outside these norms.