In today's time-crunched society, only one-quarter of us get the recommended eight hours of sleep a night. No wonder "nap pods" are cropping up in airports and shopping malls. Unfortunately, lack of sleep can take a toll, not only on your health but on your waistline, too.
That's right. Skimping on sleep may cause you to develop insulin resistance, which can lead to weight gain. It doesn't take a PhD to understand why you reach for a doughnut instead of hitting the gym when you're running on four hours of sleep.
How it works
If you limit the amount of time you spend in deep sleep, the brain thinks you're running low on energy and increases your appetite accordingly.
The research
As part of the Nurses' Health Study, 68,183 women who reported chronic sleep deprivation in 1986 were followed for 16 years using questionnaires every two years.
Women who reported sleeping five or fewer hours each night were 32 percent more likely to gain 30-plus pounds than those who slept seven hours a night.
By contrast, women who slept seven to eight hours a night had the lowest risk of major weight gain.
A study of 740 adults conducted in Quebec found that people who reported getting five to six hours of sleep each night were 69 percent more likely to be overweight or obese than those getting nine to 10 hours each night. They were 38 percent more likely to be overweight than those getting seven to eight hours.
The verdict on leptin and ghrelin
The less the subjects slept, the less leptin they secreted. Leptin is a hormone that signals the brain that you have enough energy and don't need more food. Experts claim that sleep deprivation not only reduces leptin levels but it also increases levels of ghrelin, a hormone that stimulates appetite.
Start with this small change
Replace one hour of inactive wakefulness (think watching TV) with sleeping.
Research shows that just this one small step is likely to cause a substantial reduction in calorie intake. This is especially true if you are prone to late-night snacking while watching your favourite shows. Now you have a valid reason to take a nap.
