BMC Nutrition · Published 2026-06-12 · DOI 10.1186/s40795-026-01382-5
Shadi Ghaemi, Reyhane Norouziasl, Negar Bafkar, Bahareh Jabbarzadeh Ganjeh, Kourosh Djafarian, Alireza Bahrami, Sakineh Shab-Bidar
Abstract Background We aimed to examine the relationship between the quality of macronutrients consumed at dinner versus breakfast and their effects on body composition among Iranian adults. Methods A cross-sectional study was conducted among 450 Iranian adults (aged 20–59). Anthropometric and body composition measures, including BMI, body fat percentage, fat-free mass, muscle mass, and waist-to-hip ratio, were assessed. Dietary data were collected using three 24-hour recalls, categorizing macronutrient quality (carbohydrates, fats, and proteins). ANCOVA was used to compare anthropometric and body composition measures across macronutrient tertiles for dinner versus breakfast. Non-linear associations were analyzed using restricted cubic splines. Results According to our findings, higher-quality carbohydrate intake at dinner versus breakfast showed a significant inverted U-shaped association with BMI. Conversely, saturated fat intake at dinner versus breakfast increased BMI in a U-shaped relationship, while linearly reducing muscle mass and fat-free mass. Unsaturated fat intake at dinner compared to breakfast showed a U-shaped association with BMI. Moreover, animal protein intake at dinner versus breakfast slightly increased muscle mass and fat-free mass in a reverse U-shaped pattern. However, higher plant protein intake at dinner versus breakfast reduced BMI linearly and decreased fat-free mass and muscle mass. Conclusions Higher intake of high-quality carbohydrates, unsaturated fats, and plant-based proteins at dinner versus breakfast may improve body composition, while increased consumption of saturated fats and animal proteins at dinner versus breakfast may worsen central adiposity and BMI.
Abstract from DOAJ. Public domain (CC0 1.0).
Read the article at the publisher →
Ghaemi, S., Norouziasl, R., Bafkar, N., et al. (2026). Association of macronutrient quality at dinner versus breakfast with body composition in adults living in Tehran: results from a cross-sectional study. BMC Nutrition. https://doi.org/10.1186/s40795-026-01382-5