Associations between the dietary inflammatory index with obesity and body fat in male adolescents

Background Obesity and body composition may be affected by the pro-inflammatory and anti-inflammatory components of diets. The aim of this study was to investigate associations between the dietary inflammatory index (DII) and body fat percentage (BF%) in male adolescents. Methods This cross-sectional study was carried out on 535 adolescent boys in Tehran, Iran. Bio-impedance analyzer (BIA) scale was used to measure body mass index (BMI) and body composition. A validated semi-quantitative food frequency questionnaire (FFQ) was used to measure DII. Results Participants with higher BF% (>= 19.2%) had higher BMI (P < 0.001), DII, and intake of saturated fatty acids (SFAs), compared with the participants with lower BF%. Participants with a lower DII had significantly higher intakes of fibers (P < 0.001) and lower intakes of fats, SFAs, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), oleic acid and linoleic acid (P < 0.05) compared with the participants with higher DII (P < 0.01). High BF% was positively associated to DII (OR = 1.6, CI 95%: 1.1-2.3, P = 0.019). Adjustments for age, BMI, physical activity, mothers' marital status and educational level and the number of siblings did not change the results. Conclusions Following a diet with a low inflammatory index score was associated to lower BF% in male adolescents. Thus, a diet rich in anti-inflammatory factors may effectively improve body composition and prevent obesity in adolescents. Further comprehensive studies are necessary to verify these findings and to identify the underlying mechanisms.