Associations between fiber intake and Body Mass Index (BMI) among African-American women participating in a randomized weight loss and maintenance trial

Introduction: African-American women are at increased risk for obesity, and therefore it is important to identify dietary factors that have the potential to prevent weight gain within this population. The purpose of the current study was to examine associations between daily fiber intake and Body Mass Index (BMI) over the course of an 18-month weight loss intervention for African-American women. Methods: Anthropometric measures and the Block Food Frequency Questionnaire were administered at baseline, 6-month, and 18-month follow-up between 2008 and 2010. A mixed-effects linear regression model with random intercept and time slope was used to model associations between fiber consumption and BMI controlling for time trend. Results: Associations between fiber consumption and BMI were significantly different over time ((beta) over cap (Fiber*Time)= -0.07, p-value 0.003.). There was no association between fiber intake and BMI at baseline; however, there was a significant inverse relation between fiber consumption and BMI at 6 months, and the association was even stronger at 18 months. Conclusions: Results from this study suggest that dietary fiber consumption may be particularly important within weight loss interventions tailored for African-American women.