Yes, sleeping contributes to weight loss! This might surprise you, in a world in which we are told exercise is the key to managing our weight, how can being inactive help to shed the pounds?
When we sleep, numerous, mysterious things happen to our bodies. Memories are consolidated, emotions balanced and hormones excreted. Hormones, until quite recently were a mystery to most of us, including much of the medical profession. Over the past 20 years, we have begun to better understand the many different hormones our bodies produce to regulate things like our mood, growth and sex drive. Two particular hormones influence our appetite. Leptin suppresses our desire to eat, whilst increasing our metabolism (converting fuel to energy) and ghrelin increases our feeling of hunger.
It is now well understood that when we have not slept well our levels of ghrelin increase and we get ‘the munchies‘. Those of us with lifestyles which regularly cause us to sleep badly are very likely to crave unnecessary and unhealthy snacks. This is not just a thought process along the lines of:
“I’m tired, I’ve worked hard I deserve a treat”
It is a powerful force within us, a genuine feeling that we need to eat, no different to the feeling one would experience having skipped a meal. Food as fuel is one of our basic needs and so we know not to ignore the signs. When hunger strikes we seek out the remedy but if this is between meals the choice is very likely to be a processed snack and laden with sugar.
At the University of Chicago, Dr Eve Van Cauter has spent over 30 years researching the link between appetite and sleep. Healthy young volunteers take part in studies in which their sleep pattern is controlled and their diet is measured. The studies found that tired participants given the same amount of food and taking part in similar levels of activity would feel more hungry than those who had slept well. Interestingly, the time for this difference to occur was after just two nights, so someone who consistently experiences interrupted sleep is highly likely to eat unhealthily most days.
It is thought that typically a ‘tired snacker’ will consume 300 more calories a day. Over the course of a year, this exceeds 100,000 unnecessary calories which convert to approximately 7kg or around 1 stone of weight gain.
Good nutrition and exercise are of course highly recommended to achieve weight loss but without good sleep, it will be so much harder to keep to the healthy diet.