Abstract
BACKGROUND: Considering the insufficient data regarding the relationship between isocaloric substitution of macronutrients, sleep, and mental health in the Middle East, we sought to examine this association among Iranian adult men. MATERIALS AND METHODS: This cross-sectional study was performed on 354 middle-aged Iranian men (mean age: 38.6 ± 5.34 years). Dietary data were collected using a validated food frequency questionnaire, and participants were divided into tertiles based on dietary macronutrient intake. Sleep quality was assessed using the Pittsburgh Sleep Quality Index, and sleep-related outcomes (daytime sleepiness and insomnia) and mental health (depression, anxiety, and stress) were evaluated using standard questionnaires. Multivariable logistic regression was applied to indicate the associations. RESULTS: Participants in the highest tertile of protein intake showed significantly lower odds of poor sleep quality in both crude (odds ratio [OR]: 0.55; 95% confidence interval [CI]: 0.32, 0.95) and adjusted (OR: 0.53; 95% CI: 0.30, 0.93) models. Substituting carbohydrates with an equivalent amount of protein was associated with 26% lower odds of poor sleep quality (OR: 0.74; 95% CI: 0.55, 0.99). In addition, substituting animal protein with the same amount of plant protein was linked to 29% lower odds of poor sleep quality (OR: 0.71; 95% CI: 0.51, 0.99). No other significant associations were found in both pairwise and substitution models. CONCLUSION: Our findings indicate that isocaloric substitution of carbohydrates with protein, and animal protein with plant protein, is related to lower odds of poor sleep quality. We found no other significant associations between isocaloric substitution of macronutrients and sleep-related and mental health outcomes.