The association of dietary acid load with resting metabolic rate and metabolic components in overweight and obese women: A cross sectional study

Background: Several epidemiologic studies have reported that dietary acid load (DAL) is associated with metabolic profiles; however, to our knowledge, the relationship of this dietary pattern with resting metabolic rate (RMR) among obese and overweight females remains unreported. Therefore, this study aimed to evaluate the association of DAL, RMR and metabolic components among overweight and obese adult women. Methods: This cross-sectional study was conducted on 375 Iranian adult women, aged 18–48 years. DAL indices were calculated by using a validated 147-item semi-quantitative food frequency questionnaire. Biochemical and anthropometric measures were assessed using standard methods. An impedance fat analyzer was used to obtain the body composition and an indirect calorimeter was used to assess the RMR. Result: It was observed that after correction for potential confounders, net endogenous acid production (NEAP) and potential renal acid load (PRAL) scores were inversely associated with diastolic blood pressure (DBP) (P < 0.05). NEAP index was inversely associated with RMR (β = −0.44, 95% confidence interval; CI = −1.21 to 0.32, P = 0.02), and positively associated with waist circumference (WC) (β = 1.04, 95% CI = −1.05 to 4.45, P = 0.06) and waist to hip ratio (WHR) (β = 0.01, 95% CI = −0.01 to 0.04, P = 0.04), such that subjects with higher scores in NEAP had lower RMR and higher WC and WHR. We also observed that NEAP (β = −0.44, 95% CI = −1.21 to 0.32, P = 0.02) was significance and PRAL (β = −0.23, 95% CI = −1.50 to 0.47 P = 0.07) was marginally associated with RMR. Conclusion: The results of the present study suggested that higher DAL scores may be negatively associated with lower RMR, while directly associated with greater WC, WHR, DBP, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR).