Excess Weight: Could a Lack of Sleep be the Cause?

Food and nutrition

Published on 1 June 2018
by Isabelle Huot

We all know how important it is to maintain a healthy diet and exercise regularly, but we sometimes underestimate the impacts that a lack of sleep can have on our health, and particularly on our weight. More and more data tend to suggest that a chronic lack of sleep is a contributing factor to excess weight and obesity.


People who sleep less than six hours a night have a higher BMI (body mass index) than those who sleep eight or more hours a night. The exact mechanics behind the phenomenon are still poorly understood, but several hypotheses have been proposed.


Firstly, sleeping less provides more opportunities to consume food and could therefore increase the risk of excessive caloric intake. Fatigue could make this problem worse, because when we feel tired, our reflex is to try to regain energy by eating. Moreover, someone who is tired is less likely to engage in physical activity or move in general than a well-rested person, which could also contribute to weight gain.


Some studies have also observed hormonal changes in participants suffering from a lack of sleep, particularly hormones that regulate hunger. Notably, an increase in the production of ghrelin, a hormone that regulates appetite, and a decrease in leptin levels, a hormone that creates the feeling of fullness, could be to blame, encouraging more snacking throughout the day.


The takeaway message? Hit the sack, not the snacks!

Isabelle Huot
Doctor in nutrition, spokesperson for the Kilo Cardio weight loss program