Here’s an interesting finding: the relation between the ability to lose weight and lack of sleep. According to the October 5 issue of the Annals of Internal Medicine, lack of sleep appears to compromise the efficacy of dieting to lose weight.
The study of 10 people conducted in a sleep laboratory showed that there are multiple hormonal changes associated with sleep and these may affect the ability of dieters to lose weight. Not getting enough sleep increased the subjects’ hunger, and affected their leptin and ghrelin serum concentrations (ghrelin is a hormone that reduces metabolism and promotes retention of fat). The study found that the reduced sleep decreased the proportion of weight lost as fat by 55%. Subjects who slept 8.5 hours per night lost a mean of 1.4 kg, and those who slept 5.5 hours per night lost a mean of 0.6 kg.
The major limitation to the study is that the number of subjects was quite small, so the results may not be generalized to the majority of dieters. However, I use any excuse I can to get my 8 hours of sleep.