Do Extra Z's On The Weekend Make Up For The Metabolic Damage Of Insufficient Sleep?

Ah, the weekend. An oasis (sometimes!) of time to relax, recharge, and try to make up for the sleep we are not getting during the week. We know that not getting enough sleep has steep health costs, including a higher risk of diabetes, obesity, and even higher mortality. So does making up for lost sleep on the weekend ‘cancel out’ the negative health effects of not sleeping enough during the week?

A recent study was undertaken to answer this question. They assigned 36 young, healthy adults of healthy weight, who typically slept 8 hours per night in their usual life, to one of three groups, for 9 days: (starting on a Monday)

Group 1 was allowed to sleep up to 9 hours per night
Group 2 was allowed to sleep up to 5 hours per night
Group 3 was allowed to sleep up to 5 hours during the week, with as much sleep as they wanted on the weekend (this group ended up sleeping only a total of 3 extra hours above their usual on the weekend, even though they had missed out on 12 hours of sleep during the week).

After 9 days, they found:

A reduction in the body’s sensitivity to insulin after just 3 days of sleep deprivation (Groups 2 and 3)
An even greater reduction in insulin sensitivity in those who were allowed catch up weekend sleep (Group 3)
Those who were allowed recovery sleep on the weekend and then went back to sleep restriction during the week had a delay of their circadian rhythm of melatonin (called ‘social jetlag’) (Group 3)
Both sleep deprived groups consumed 500-640 calories more after dinner each night, on the nights they were sleep deprived (Groups 2 and 3)
People in both sleep restricted groups gained an average of 3 pounds – yes, in just 9 days!

This study shows us that sleep deprivation is hard on our metabolism and leads to weight gain, and that catch up sleep on the weekend not only doesn’t make up for being sleep deprived all week long, but also messes up our internal clocks. This doesn’t necessarily mean that we shouldn’t try to catch up on sleep during the weekend – in fact, other research looking at data over 13 years has shown that people who make up for lost sleep on the weekend have the same mortality rate than those who sleep consistently 6-7 hours per day, whereas those who consistently sleep 5 hours or less every night of the week had a 65% increased mortality risk. It would be interesting to know if catch up sleep could make up for short sleeps on say, just one or two nights during the week. But the best policy would be to try not to deprive ourselves of sleep during the week in the first place.

Disclaimer: I am fully and completely guilty of sleep deprivation myself – yes, I really do write some of these blogs at 4AM! 😉

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