According to the Annals of Internal Medicine, people who are sleep deprived (are there people who aren't?!) might have a much tougher time losing weight. Wuh? As if the dieting and exercise weren't challenging enough to integrate into the daily routine, dieters will now have less time in which to do it? Furthermore, not getting enough sleep can affect not only how much you lose, but what you lose. God help me.
If you prefer to read non-medical jargon, MedlinePlus has a good overview of this research:
Researchers found that the dieters lost the same amount of weight under both conditions -- just under 7 pounds, on average. But during the sleep-restricted period, they mainly lost muscle rather than fat.When participants got 8.5 hours of sleep, more than half of their weight loss came from shedding fat; when they got 5.5 of sleep, only one-quarter of their weight loss came from fat -- translating to a 55 percent reduction in fat loss.Instead, the majority of people's weight loss during the sleep-restricted period came from lean body tissue, which refers to muscle and any other body tissue that is not fat.
Sleepy people may also be hungrier throughout the day because sleep deprivation may trigger the hunger hormones leptin and ghrelin. While this study took place in a controlled environment and may not be strictly applied to a 'real world' environment, I think it is safe to say that there are more than a few reasons to get more sleep.
I've always thought of weight loss in terms of diet and exercise. Period. This new equation changes the game quite a bit, but it's probably time that I stop pushing the margins of my day to such extremes that I sometimes struggle to put simple sentences together.