Women with poor sleep quality were found to be at more than 2 times greater risk of obesity, with this association occurring only in those who did not meet recommended dietary standards.
With previous research having linked poor sleep quality and duration with risk of obesity, researchers noted that the underlying mechanism behind this association remains unclear. However, several potential mechanisms have been identified, which include decreased physical activity and a low-quality diet.
“Restricted sleep might affect food intake, appetite, satiety, and energy balance by modifying responses to hormones, such as leptin and ghrelin,” explained the study authors. “Moreover, poor sleep quality is often associated with unhealthy habits and lifestyle modifications, such as decreased physical activity and the consumption of high-calorie foods and beverages.”
Hypothesizing that overall diet quality may be related to sleep status and obesity, they sought to examine the potential link in a cross-sectional analysis of Korean men and women participating in the prospective Ewha-Boramae cohort study.
In the analysis, 1165 participants aged 19 to 80 years who underwent a full health assessment annually or biennially at Seoul National University Boramae Hospital were included (men, n = 737; women, n = 428).
Eligible participants provided data on sleep duration, categorized as 7 hours or more (adequate) and less than 7 hours (insufficient); sleep quality, measured via Pittsburgh Sleep Quality Index (PSQI) values of greater than 5 (poor quality) and 5 or less (good quality); and diet quality, evaluated by the Recommended Food Score (RFS).
All participants were stratified by body mass index (BMI) into 2 groups:
In assessing characteristics of obese participants, the group of men with obesity had higher proportions of married adults and current smokers than the group of nonobese men, whereas women with obesity had higher proportions of older and menopause adults than nonobese women. The proportion of physical activity participation among men and women did not differ between the 2 BMI groups.
Within the study cohort, significantly higher rates of short sleep duration (< 7 hours) and poor sleep quality (PSQI > 5) were observed in obese women compared with nonobese counterparts–a significant trend that was not found in men. Women were also found to have significantly lower sleep quality indicators and lower diet quality compared with men.
Although no significant association was found between sleep duration and obesity with RFS in both men and women, women whose RFS scores were less than or equal to the median score (21) and reported poor sleep quality were at more than 2 times greater risk of obesity. This association remained significant after adjusting for covariates, including age, marital status, smoking status, physical activity, and menopause status (odds ratio, 2.198; 95% CI, 1.027-4.704).
No significant association was shown between sleep duration and obesity according to the RFS median in men.
Researchers noted several limitations to the study findings, such as the use of cross-sectional data and the use of only RFS to assess the diet quality. They concluded that future studies with larger sample sizes and a prospective or interventional design are warranted to further assess the link between diet quality or dietary patterns and sleep quality with obesity.
Hur S, Oh B, Kim H, Kwon O. Associations of diet quality and sleep quality with obesity. Nutrients. 2021;13(9):3181. doi:10.3390/nu13093181