Sleep lean

Sleep is a popular past-time. It is possible the only human hobby currently more widely adopted than Facebook. Then again, it’s not really a hobby, is it? We need our sleep and the evidence is that pretty much all life-forms except possibly bacteria, viruses, and protozoa also need it. Research tells us that, as well as mammals and birds, flies, worms and zebrafish all require rest. It appears that sleep becomes necessary once you decide to tie two or more cells together. In humans the reasons for sleep are many and a new study has shown that one of those reasons is maintaining a healthy weight.

For the study researchers examined 300 women aged between 17 and 26. The women had their body composition measured and then had activity monitors attached to them that would track their movements during the day and record their sleep patterns at night.

The results showed that sleeping less than 6.5 hours per night or more than 8.5 hours was linked to higher levels of body fat. Sleeping between 8 and 8.5 hours per night was tied to the lowest levels of body fat. Previous research has also shown that a decent amount of sleep keeps you slim but this study made an additional finding.

It emerged that people whose sleep and wake time varied by more than 90 minutes had more body fat than those whose variations were less than 60 minutes. In particular wake time was tied to body and those who woke at the same time every day had the least body fat.

So it seems that consistency in sleep times and not just amount of sleep is important. This ties in with a study reported a few weeks ago in this column which found that children with consistent sleep times tend to have better behaviour. Aldous Huxley said that the only completely consistent people are dead but as far as your sleep goes it seems a little consistency can actually enhance life.