Our society is sleep deprived. On average, Americans are sleeping one hour less per night than they did 20 to 30 years ago. The National Sleep Foundation estimates that the average American gets six hours and 40 minutes of sleep on week nights. The fast-paced American lifestyle and long work days are contributors; in one survey, the National Sleep Foundation found that Americans are spending 9.5 hours on the job, and over 17 hours out of bed.
This lack of sleep is taking a toll on our health, and our weight. There is a growing body of research showing that a lack of sleep increases your risk of weight gain. One way it does this is by disturbing your body’s natural ability to regulate appetite. A recent study published in the American Journal of Clinical Nutrition attests to this.
In this study, men participated in 2 conditions. In one condition, they got 8 hours of sleep. In the other condition, they got 4 hours of sleep. The next day, the men ate as much as they wanted. Food intake and physical activity were measured, as well as sensation of sleepiness.
The results for food intake are shown in the following figure:
When the men only got 4 hours of sleep, they ate 559 more calories than when they got 8 hours of sleep! Their hunger levels before breakfast and before dinner were also greater.
The results for physical activity were interesting. When the men were sleep restricted, they had higher physical activity levels in the afternoon than when they weren’t restricted. However, the night after sleep restriction, their activity levels were lower than when they got sufficient sleep. So there didn’t appear to be any major differences in overall physical activity between the sleep conditions.
Remember that weight gain is a matter of energy imbalance; when you consume more calories than you burn, you gain weight. The following figure shows the estimated energy balance for the men when they were sleep deprived versus when they weren’t sleep deprived:
You can see the men were in energy balance when they got 8 hours of sleep; when the men were sleep deprived, they were in a positive energy balance of 444 calories per day. If this sleep deprivation was kept up for an entire year, it would result in over 40 pounds of weight gain!
While the sleep deprivation in this study is more than what most people experience, it is still clear that not getting enough sleep can be a problem. This study is Just one of a growing number of studies showing how a lack of sleep can wreak havoc with your appetite. You should be getting 7 to 8.5 hours of sleep per night. Getting enough sleep is critical if you want to lose weight and keep it off. In this case, if you snooze, you will definitely lose….weight.