ABSTRACT
PURPOSE: Previous studies have shown the connection between diet quality to sleep quality and weight status, although the relationship between Lifelines Diet Score (LLDS)-a fully food-based score that uses the 2015 Dutch Dietary Guidelines and underlying international literature-and sleep quality has not been evaluated in overweight and obese individuals yet. This observational study was conducted on overweight and obese adult females to assess the relationship between adherence to a LLDS pattern and sleep quality in Iran. METHODS: A cohort of 278 overweight and obese women aged above 18 years was enrolled and their dietary intake was assessed using a 147-item, semi-quantitative, validated food frequency questionnaire. Pittsburgh Sleep Quality Index (PSQI), a self-reported questionnaire including 19-items, was applied to estimate sleep quality among the target population. Diet quality indices (LLDS) were calculated using the P.C. Vinke, et al. method, based on the 2015 Dutch Dietary Guidelines and the underlying literature. RESULTS: Subjects in the highest LLDS tertile (those who had adhered closely to the food-based score) were older, compared to the lowest tertile (37.57 ± 7.77 versus 34.57 ± 9; p = 0.01). It was shown that about 25.5% of our subjects have poor quality sleep and 39% have better sleep quality which were mostly in the third tertile with greater LLDS. The parallel values in the first tertile were 29.9% and 46.8%, respectively (p = 0.02). Binary logistic regression was applied to evaluate the association between adherence of LLDS and sleep quality. The result has shown that the LLDS were correlated with lower risk poor sleep quality, wherein those who were in higher tertile (higher adherence to LLDS) had better sleep quality (odds ratio [OR]:0.586, 95% confidence interval [CI] (0.285-1.207), p = 0.009) and the result was not affected by adjusting for potential cofounders including age, education levels, and economic levels, sleep quality remained significantly associated with [OR]: 0.531, 95% confidence interval [CI] (0.248-1.138, p = 0.014). CONCLUSIONS: From this observational study, the higher LLDS can be related with better sleep quality in overweight and obese women. LEVEL OF EVIDENCE: Level IV, evidence obtained from multiple time series with or without the intervention, such as case studies.
