Association of Pro-Healthy Diet Index and Non-Healthy Diet Index with Body Composition: Baseline Results from Cohort Study

Background: Various dietary patterns have different effects on the body composition of adults. This study investigated the association of pro-healthy diet index (PHDI) and non-healthy diet index (NHDI) with body composition in employees of Shiraz University of Medical Sciences, Shiraz, Iran.Methods: This cross-sectional study was performed on baseline data from the Cohort Study of Employees of Shiraz University of Medical Sciences, Shiraz, Iran. Out of 4550 participants, 3380 were included in this study. Body composition was obtained from cohort database. PHDI and NHDI were calculated by a 113-item food frequency questionnaire.The association of PHDI and NHDI with body composition was assessed depending on the type of variable using regression methods along with the adjustment of confounders.Results: There was a positive association between PHDI and body fat mass (coef.=1.04; CI: 0.22-1.86), fat free mass (coef.=1.17; CI: 0.27-2.07), skeletal muscle mass (coef.=0.71; CI: 0.19-1.23), fat free mass index (coef.=0.33; CI: 0.04-0.67), fat mass index (coef.=0.31; CI: 0.01-0.61), and bone mineral content (coef.=0.07; CI: 0.02-0.12). However, PHDI was not related to body fat percent. There was no significant correlation between NHDI and body composition.Conclusion: PHDI had a positive correlation with skeletal muscle mass, bone mineral content, body fat mass, fat free mass, fat free mass index, and fat mass index. Yet, no association was found between NHDI and body composition.