The Association Between Content and Type of Dietary Protein with Metabolic Syndrome Risk Factors in Adults: Tehran Lipid and Glucose Study

This cross-sectional was conducted to investigate the association between dietary protein content and animal to plant protein intake ratio and the risk factors of metabolic syndrome in Tehranian adults. This study was conducted using data from adults aged 19-70 years, who participated in third phase of Tehran Lipid and Glucose study. Dietary data were collected using a validated semi-quantitative food frequency questionnaire with 168 food items. Total dietary protein, and intake of protein from animal and plant sources were estimated. The association between total protein and animal to plant protein intake ratio with metabolic syndrome risk factors was determined by multivariate linear regression models with adjustment for confounders. In the present study, 45% of participants were men. Mean ages of men and women were 40.5±13.6 and 38.6±12.8 y, respectively. The mean protein intakes were 13.7 and 13.6% of energy in men and women, respectively. There was an independent inverse association between protein intake and animal to plant protein intake ratio, in women. Fasting glucose was positively associated with total protein intake and inversely associated with animal to plant protein ratio, in both men and women. There was positive association between protein intake and HDL-C. There was an inverse association between protein intake and diastolic blood pressure in women. Amount and type of dietary protein, independent the risk factors of energy density, dietary fat, carbohydrate and fiber, are associated with metabolic syndrome.