Dietary Patterns Defined a Posteriori or a Priori in Relation to Obesity Indices in Iranian Women

Background: Obesity is a multifactorial chronic disease that develops from multiple interactions between genetic, physiologic, metabolic, socioeconomic, and lifestyle factors. This study investigated the associations between dietary patterns defined a posteriori or a priori and obesity indices in a sample of Iranian women. Methods: Two hundred and sixty-seven women aged 30-50 years participated in this cross-sectional study. Obesity indices including body mass index (BMI) and waist circumference (WC) were measured according to standard procedures. Dietary intakes were evaluated with a valid and reproducible 168-item food frequency questionnaire. Dietary patterns were defined a posteriori or a priori by performing factor analysis and by assessing participants’ adherence to the dietary approaches to stop hypertension (DASH) diet, respectively. Results: After controlling for potential confounders in the analysis of covariance models, multivariable adjusted means of the BMI and WC of subjects in the highest quintile of the DASH pattern score defined a priori were significantly lower than those in the lowest quintile (for BMI: mean difference -2.9 kg/m2, p=0.003; and for WC: mean difference -5.4 cm, p=0.009). Similar results were observed in case of the healthy pattern score defined a posteriori (for BMI: mean difference -3.7 kg/m2, p<0.001; and for WC: mean difference -6.5 cm, p=0.002). By contrast, multivariable adjusted means of the BMI and WC of subjects in the highest quintile of the unhealthy pattern score defined a posteriori, were significantly higher than those in the lowest quintile (for BMI: mean difference 3.9 kg/m2, p=0.001; and for WC: mean difference 8.2 cm, p=0.001). Conclusion: These findings indicated significant associations between dietary patterns defined a posteriori or a priori and obesity indices in Iranian women.