Lack Of Sleep Can Make Dieters Lose Muscle Instead Of Fat

People who are on a low-calorie diet will lose the same amount of weight whether they sleep an average of 8.5 hours or 5.5 hours each night. However, those on 8.5 hours will lose much more fat, while those on 5.5 hours lose mainly muscle, instead of fat, according to an article published in the peer-reviewed journal Annals of Internal Medicine. This shows us that adequate sleep is a key contributor to managing body weight.

Ten overweight males and females lived in a sleep research centre for two separate periods, lasting two weeks each. During each period they were on identical low calorie diets. However, during the first 2 week period they had 8.5 hours sleep each night, while in the second period they slept just 5.5 hours each night.

Although sleep duration was found not to affect the total amount of weight loss – they all lost an average of nearly 7 pounds – the dieters lost mainly muscle rather than fat during their sleep-deprived two-week session. The researchers found that:

·While on 8.5 hours sleep each night over 50% of the participants’ weight loss consisted of fat

·While on 5.5 hours sleep each night, approximately 25% of the participants’ weight loss consisted of fat – in other words, they lost 55% less fat than when they were sleeping 5.5 hours

Weight-loss dieting usually involves a certain amount of lean tissue (muscle) loss. The dieter should try to lose as little lean tissue as possible. This can be overcome by physical activity (exercise). However, it is clear that not getting enough sleep can undermine any attempts a dieter may make to limit lean tissue loss.