I’ve been thinking recently about the relationship between sleep and food. When I began intermittent fasting (randomly skipping meals, usually breakfast) I found that the most important rule for success was this: I can either go without sleep or without food, but not both. If I stay up late or slept poorly, I need three meals per day. Failing to follow that rule leaves me only semi functional. If I get enough sleep, two meals in a day is no problem.
Last weekend was the daylight savings time switchover. We lost an hour. On Sunday night, for reasons I don’t understand, I woke up several times and had trouble getting back to sleep. On Monday I ate a normal breakfast and lunch, but still came home ravenous and craving carbohydrates.
I wonder if the paleo emphasis on sleep quality might be almost as important as that on food quality. Lots of Westerners seem to push off as much sleep as they can and compensate with coffee or energy drinks. In the long run, that in itself may be a recipe for terrible health.
Then at FuturePundit this week, I ran across a link to a study on sleep and appetite.
The researchers studied 17 normal, healthy young men and women for eight nights, with half of the participants sleeping normally and half sleeping only two-thirds their normal time.
Participants ate as much as they wanted during the study.
- The sleep deprived group, who slept one hour and 20 minutes less than the control group each day consumed an average 549 additional calories each day.
- The amount of energy used for activity didn’t significantly change between groups, suggesting that those who slept less didn’t burn additional calories.
- Lack of sleep was associated with increased leptin levels and decreasing ghrelin — changes that were more likely a consequence, rather than a cause, of over-eating.