Soy product consumption and association with health characteristics and dietary quality indices in Isfahan, Iran

BACKGROUND To determine the average intake of soy products and its association with socio-demographic, general and health characteristics, and dietary quality indices among the population of Isfahan, Iran. METHODS In this descriptive cross-sectional study conducted on 491 subjects in 2013-2014, grocery stores, nuts stores, chain stores, and supermarkets from different areas of Isfahan Municipality were visited. Shop owners were asked to report the amounts of soy products sales (soy nut, processed soy protein, soy milk and soy yogurt). Furthermore, a food frequency questionnaire was completed from 496 customers by an experienced nutritionist. Mean sales and intake of soy products and dietary intakes including dietary quality indices and mean adequacy ratio (MAR) as well as anthropometric and socio-demographic variables were assessed. RESULTS Soy protein and soy yogurt are the highest [673 ± 81 (g/month)] and lowest [420 ± 148 (g/month)] purchased soy products, respectively. While soy nut [63 ± 10 (g/month)] was consumed to the lowest amount, soy protein [236 ± 39 (g/month)] was the most consumed soy product. Subjects with higher consumption of soy products were older and had higher intake of protein, vitamin C, zinc and iron, and lower intake of whole grains, legumes, and vegetables as well as greater values of MAR and dietary diversity score as well as nutrient adequacy ratio for vitamin C. CONCLUSION Soy protein is the most purchased and consumed soy product among people living in Isfahan. More intakes of whole grains and vegetables among those with higher consumption of soy foods could define greater quantities of zinc, iron and vitamin C in the diet. Soy consumption had a reverse correlation with body mass index.