We all know (or should know) that getting plenty of sleep is important to normal functioning and health. And sleep deprivation has been associated with an increased risk of obesity in both animals and humans — it results in hyperphagia (increased appetite) and weight gain. But what if you can't get the requisite seven or eight hours on a regular basis? Or what if you're a student who simply has to cram all night before an important exam? The good news is that you can catch up. And the better news is that catching up seems to be associated with less risk of overweight and obesity — at least according to a recent study published in the journal Sleep.
Dr. Hee-Jin IM of the Korea University Anam Hospital in Seoul, Republic of Korea and colleagues focused on the amount of weekend sleep extension (catch-up sleep) that approximately 2200 adults reported getting on a regular basis. Overall, the average duration of sleep was 7.3 hours per night, and the average BMI was 23, within the normal range. Of those individuals, 932 reported sleeping longer on weekends than during the week by an additional 1.8 hours.
Furthermore, the BMIs of the weekend catch up sleepers were significantly lower than that of the folks who did not catch up on weekends — 22.8 vs 23.1 respectively, after controlling for age, gender, average sleep duration, and other demographic factors. And this relationship between catch-up sleep and BMI was dose-dependent, the researchers reported — for every additional hour of weekend sleep, there was a 0.12 decrease in BMI units.
The authors noted that there were some limitations to their study — the most important of which is that they had to rely on reported, rather than measured heights and weights, as was the duration of daily and weekend sleep.
Despite these drawbacks, the results of this study suggest that advice to "indulge" in catch sleep by those who are chronically sleep-deprived, could be another tool with which to fight the obesity epidemic.