Too little sleep disrupts our metabolism in such a way that it becomes a significant contributor to weight gain.
Research with dieters who cut back on sleep over a 14 day period found the amount of weight they lost from fat dropped by 55% even though their calories stayed equal. The sleep restricted dieters reported feeling hungrier, lacking energy and less satisfied after having their meals.
With less sleep our metabolism becomes less efficient. Research shows that in as little 4 days of reduced sleep our insulin response capability can drop by more than 30%. Insulin is a hormone that changes sugar, starches and other foods into the energy we require. The outcome of such a drop in insulin is our body will have trouble processing fats from our bloodstream and seek to store them with the result being weight gain.
The connection between sleep and exercise is well known but sleep also plays a significant role in how our body senses hunger and manages weight.
There are two key hormones that interact in our weight management. These are Ghrelin and Leptin. Ghrelin signals our body to eat and leptin signals when our body to stop eating. For example, our ghrelin levels are highest before we eat and lowest about 60 minutes after eating. Our leptin levels move more erratically and tend to vary according to our body proportion to fat mass. When operating properly, leptin levels do rise as fat increases telling our brain we have enough energy stored. As our fat levels go down the leptin will also go down such that we start to eat again. For the obese person the brain is thought to not be sensitive to the leptin signals of how much fat is stored.
In short, when we are sleep deprived (quality and quantity) the balance between these hormones (ghrelin and leptin) is disturbed and causes the following effects on us:
- Our leptin levels decrease, while our ghrelin increases leaving us not only sleep deprived but also hungry.
- Sleep deprivation leads to more eating. It is estimated an extra 500 calories following a poor nights sleep.
- Less food quality evaluation after less sleep which leaves us increasing our snack intake while also using lower quality high carbohydrate foods. Proteins, nuts and greens are just not as enticing as pizza and beer.
- Finally, our energy systems function poorly. Less sleep means our cells become more resistant to receiving the insulin signals to absorb glucose from the bloodstream to create energy.
It is clear from the research that improved sleep is fundamental to better weight management and should be included as part of any weight management and overall wellbeing process.
References
• Van Cauter, Eve, Ulf Holmbäck, Kristen Knutson, Rachel Leproult, Annette Miller, Arlet Nedeltcheva, Silvana Pannain, Plamen Penev, Esra Tasali, and Karine Spiegel. “Impact of sleep and sleep loss on neuroendocrine and metabolic function.” Hormone Research in Paediatrics 67, no. Suppl. 1 (2007): 2-9. (link)
• Brondel, Laurent, Michael A. Romer, Pauline M. Nougues, Peio Touyarou, and Damien Davenne. “Acute partial sleep deprivation increases food intake in healthy men.” The American journal of clinical nutrition 91, no. 6 (2010): 1550-1559. (link)
• Greer, Stephanie M., Andrea N. Goldstein, and Matthew P. Walker. “The impact of sleep deprivation on food desire in the human brain.” Nature communications 4, no.
1 (2013): 1-7. (link)
• Donga, Esther, Marieke van Dijk, J. Gert van Dijk, Nienke R. Biermasz, Gert-Jan Lammers, Klaas W. van Kralingen, Eleonara PM Corssmit, and Johannes A. Romijn. “A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects.” The Journal of Clinical Endocrinology & Metabolism 95, no. 6 (2010): 2963-2968. (link)