Independent associations of sodium intake with measures of body size and predictive body fatness

Objective Observational studies highlight a possible relationship between sodium intake and obesity. This investigation explores the cross-sectional relationships between sodium intake and measures of body size and fatness (body mass index [BMI], weight, waist circumference, predictive body fatness). Methods Analyses were performed using data from participants in the National Health and Nutrition Examination Survey (NHANES) 2009-10 with two 24-h dietary recalls and measures of body size and fatness (n = 4,613). Regression analyses assessed the relationships of sodium (1,000 mg/day) with outcomes, adjusting for caloric intake. Analyses are presented overall and by sex; data were weighted to be representative of the non-institutionalized US adult population. Results Positive associations between sodium intake and measures of body size and predictive body fatness were observed, and the magnitude of association was larger in women than in men. For each 1,000 mg/day higher sodium intake, BMI was 1.03 kg/m² higher; weight was 2.75 kg higher; waist circumference was 2.15 cm higher; and predictive body fatness was 1.18% higher after adjustment for energy intake. Conclusions Longitudinal analyses examining associations between sodium intake and measures of body size and body fatness are needed.