In the last few years, a major breakthrough in metabolism regulation was made. It was found that two hormones called leptin and ghrelin are crucial for regulating what makes us hungry and what makes us feel satiated. Separately, we know that sleep is related to hunger: when we are tired, we tend to eat more, and we tend to eat fewer healthy things. Given this knowledge, it is reasonable whether to ask whether these hormones are a mediating factor between sleep insufficiency and hunger.
This question was examined using a large cohort of individuals (over 1000 people). Each research participant underwent a full overnight sleep study and reported their usual sleep habits. What’s more, each individual provided a blood sample, with which the researchers were able to extract leptin and ghrelin levels. Body mass index (BMI) was also calculated so that a measure of weight could be obtained.
It was found that, as expected, shorter sleep duration was associated with a higher BMI, meaning less sleep is linked with higher body weight. Also, shorter sleep was associated with lower leptin levels (which is a bad thing), and high ghrelin levels (which is also a bad thing).
These data suggest that short sleep duration, experienced by a large portion of the general population, is linked with hunger-inducing hormones and higher BMI. Although this study was unable to find a “causal” relationship between sleep loss and these others factors (i.e., it was not proven that sleep causes obesity and hormone alterations directly), these data do strongly suggest a link.
Given that sleep apnea is often associated with short sleep duration, this is a pretty scary finding. For many suffering from sleep apnea, excess weight is already the enemy. Losing sleep from untreated apnea may cause these hormones to fluctuate, thereby causing more hunger and more weight gain. Luckily, sleep apnea treatment can alleviate short sleep that may be caused by apneas so that hunger and weight can be maintained (or reduced!). So, as always, get treated and stick to it!
Source: Taheri, S., Lin, L., Austin, D., Young, T., & Mignot, E. (2004). Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS medicine, 1(3), 210.