I encourage my patients to get adequate sleep. Getting enough sleep just results in a better sense of well being and energy. But does it have any impact on weight loss? It has been established that sleep deprivation results in serotonin depletion in the brain, and the lack of serotonin, in term, leads to sugar craving. But does sleep have any other benefits?
In a recent study, participants had their caloric intake restricted to 90% of their resting metabolic rate, and were assigned to 5.5 or 8.5 hours of sleep for 2 weeks. A few months later, they crossed over to the other sleep schedule for another 2 weeks. The amount of fat lost, fat-free body mass, and some hormones were monitored. Both groups lost about 6 and a half pounds. But the people who slept for 8.5 hours lost 56% of their weight as fat, and the people who slept for 5.5 hours lost 25% of their weight as fat. The sleep deprived patients also had lower resting metabolic rates and were more hungry.
So what does it mean? If you’re in the process of losing weight, you will lose more of your weight as fat if you get enough sleep. If you stay up late, get up early, run on fumes all day, and try to caffeinate yourself through the day, you will lose less fat. And if you’re losing less fat, it means you’re losing more muscle, which is something you want to avoid.