The connection between sleep and weight.

The need for sleep varies for each of us. As a general rule though we need somewhere between 7 to 9 hours each night. Illness, sleep disorders and work schedules can result in us not getting enough sleep but increasingly the demands of the modern lifestyle (and 24 hour access to the internet) are causing wide-spread lack of sleep.

Chronic sleep deprivation is a relatively new phenomena – in just over fifty years there has been a big change in the number of hours slept per night. In 1960 the average nightly sleep duration was about 8.5 hours. But today the average adult 38-50 years sleeps for just 6.1 hours on week nights. This drastic reduction in sleeping hours coincides with increasing rates of obesity and metabolic disorders in westernised countries and numerous studies have linked the increase in obesity with the general reduction in sleep times observed in most of the industrialized countries.

There are a number of reasons why we can put on weight when we don't sleep enough:

  1. When we don't get enough sleep we have an increased appetite, due to increases in the hormones that make us feel hungry and to satisfy this increased appetite we can end up eating up to 500kcals more per day compared to days when we have sufficient sleep.
  2. Our metabolic rate decreases by as much as 15% meaning that we burn calories much slower.
  3. We are not motivated to exercise and even our incidental exercise decreases, further decreasing our metabolic rate.
  4. When we are sleep deprived our body doesn't burn fat as efficiently - it prefers to burn lean muscle.

The fact that sleep plays such a major role to our ability to put on weight indicates that it may well be the link between traditional diet strategies and successful weight loss. In other words if you want to diet successfully you have to not only eat and exercise right - you also have to sleep right.