Lack of sleep is associated with weight gain, but why is this? Is it just because sleep deprivation makes us grumpy and we “self-medicate” with food?
People who get poor quality sleep, or not enough sleep, start craving high carbohydrate and high fat foods that are more likely to cause weight gain. And sleep deprivation makes us less likely to eat health foods, like fruits and vegetables.
It turns out that this effect may be the result of alterations in the brain’s release of chemicals that are affected by cannabis – the so-called endocannabinoids. The chemistry of this process is remarkably similar to how smoking marijuana causes the “munchies.”
Both sleep deprivation and smoking weed stimulate the endocannabinoid system and this, in turn, changes how our brain’s smell center (the olfactory cortex) responds to the aromas of different types of food.
Both sleep deprivation and marijuana make high carbohydrate and high fat foods smell more appealing, and as our appetite for food changes, we gain weight, because the foods that seem appealing have more calories.
What is meant by “sleep deprivation” – does this happen when we don’t get at least eight hours of sleep a night, which seems to be what the sleep doctors recommend?
This study found that the weight gain effect was seen in people getting less than six hours of sleep a night.
We have consistently recommended at least 7 to 7 and a half hours of sleep, and that seems to be adequate to avoid the “munchies” and weight gain in this study.
Bhutani et al. eLife 2019;8:e49053. DOI: https://doi.org/10.7554/eLife.49053