Somaye Fatahi
1,2 
, Mostafa Qorbani
3, Pamela J. Surkan
4, Leila Azadbakht
1,5* 1 Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
2 Pediatric Gastroenterology, Hepatology and Nutrition Research Center, Research Institute for Children’s Health, Shahid Beheshti University of Medical sciences, Tehran, Iran
3 Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
4 Department of International Health John Hopkins Bloomberg School of Public Health, Baltimore, USA
5 Diabetes Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
Abstract
Introduction: Diet-induced acid load may be associated with overweight and obesity as well as with diet quality. We aimed to study how dietary acid load is associated with overweight, obesity and diet quality indices in healthy women.
Methods: We randomly selected 306 healthy 20 to 55 year-old women from health centers affiliated with Tehran University of Medical Science. They were enrolled in a cross-sectional study between June2016 and March 2017. Potential renal acid load (PRAL), net endogenous acid production (NEAP) and dietary acid load (DAL) were calculated for each person. Dietary quality index international (DQI-I),mean adequacy ratio (MAR), and energy density (ED) were estimated. Anthropometry was measured using standard protocols. Nutritional data were obtained from food frequency questionnaires (FFQ). We used multivariable logistic regression models to assess dietary acid load indices in relation to overweight, obesity and abdominal adiposity.
Results: Participants had a mean age of 32.4 years. The number and percentage of women who were overweight, obese and who had abdominal obesity were 94(30.7), 38(12.4) and 126(41.2), respectively.The odds of obesity (adjusted odds ratio; Adj. OR = 2.41, 95% confidence interval; CI:1.01-5.74,P = 0.045) and abdominal adiposity (Adj. OR = 2.4, 95% CI:1.34-4.60, P = 0.004) increased significantly with tertile of DAL. Other dietary acid load indices (PRAL and NEAP) showed no significant association with obesity, overweight or abdominal obesity. As dietary acid load scores (PRAL, NEAP and DAL)increased, DQI-I and MAR significantly decreased whereas ED significantly increased across tertilesof dietary acid load indices (P < 0.001).
Conclusion: Dietary acid load is associated with obesity and abdominal obesity and is also considered an indicator of diet quality.