We all know that getting enough sleep is one of those things that contributes to many areas of your life – including weight loss. New research into this topic has revealed that early to bed, early to rise does in fact make you healthier.
The study was carried out with an (arguably quite small) sample of 23 late sleepers and 28 normal sleepers between the ages of 18 and 71. The subjects were asked to record what they ate in a food log, noting down the times they ate and the types of food they were eating. They also wore wrist actigraphs, which measure whether or not you are awake or asleep.
From the study:
On average, the late sleepers went to bed at 3:45 a.m., awoke by 10:45 a.m., ate breakfast at noon, lunch at 2:30 p.m., dinner at 8:15 p.m. and had their final meal at 10 p.m. Normal sleepers, by contrast, were asleep by 12:30 a.m., woke up around 8 a.m., had breakfast by 9 a.m., lunch at 1 p.m., dinner at 7 p.m. and their last snack around 8:30 p.m.
Interestingly, the late sleepers almost universally had a much more unhealthy lifestyle in general than those who kept reasonable hours. They got less sleep on average (5 and a half hours, versus 6 and a half for the normal sleepers), ate more fast food (5 times a week as opposed to 3), drank more full-fat sodas and ate less fruit and vegetables.
You Are When You Eat
The main difference however was in when the participants ate their calories. Those who went to bed late had roughly 300 calories more in their dinners, and ate substantially more calories after 8pm. This, researchers say, makes it difficult for the body to stick to the circadian rhythm – our internal clocks that are synchronized with the 24-hour light-dark cycle of the earth.
The findings of the study, while preliminary, suggest that after controlling for the amount and quality of sleep all participants got, calories consumed after 8pm contributed most significantly to weight gain.
The study was small, but the results have been replicated using rats, and seem to show conclusively that eating outside of normal eating hours tends to promote weight gain and slow metabolism.
Exact Link Unknown
Exactly why this occurs is still open to guesses, but the most common theory is that our bodies know when it is time to be eating, and when it is time to sleep. When we eat when we should be sleeping, our digestive systems respond more sluggishly to the food we eat, processing it in a way that is least efficient.