BRIEF RESEARCH REPORT article

Front. Nutr.

Sec. Clinical Nutrition

Volume 12 - 2025 | doi: 10.3389/fnut.2025.1634215

This article is part of the Research TopicRecent Insights in Vegetarian NutritionView all 3 articles

Dietary acid load on the Mediterranean and a Vegan Diet: A Secondary Analysis of a Randomized, Cross-Over Trial

Provisionally accepted
Hana  KahleovaHana Kahleova1*Cristina  MaracineCristina Maracine1Joseph  HimmelfarbJoseph Himmelfarb1Arathi  JayaramanArathi Jayaraman1Tatiana  Znayenko- MillerTatiana Znayenko- Miller1Richard  HolubkovRichard Holubkov2Neal  D BarnardNeal D Barnard1
  • 1Physicians Committee for Responsible Medicine, Washington D.C., United States
  • 2The University of Utah, Salt Lake City, United States

The final, formatted version of the article will be published soon.

Background: Evidence suggests that changes in dietary acid load may influence body weight, and the purpose of this secondary analysis was to assess its role in the context of the Mediterranean and a vegan diet in overweight adults.In this randomized cross-over trial, 62 overweight adults were randomized to a Mediterranean or a low-fat vegan diet for 16-weeks, separated by a 4-week washout. Change in body weight was the primary outcome. Three-day dietary records were analyzed, and Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP) were calculated as markers of dietary acid load, and their relationship was tested with changes in body weight.Compared with no change on the Mediterranean diet, PRAL and NEAP significantly decreased on the vegan diet; effect sizes: -25.8 (95% CI -34.1 to -17.5); p<0.001; and -27.1 (95% CI -35.4 to -18.7); p<0.001, respectively. Across both diets, changes in PRAL and NEAP were positively associated with changes in body weight in the first 16 weeks of the study: r=+0.34; p=0.009; and r=+0.39; p=0.002, respectively, as well as in the second 16 weeks: r=+0.59; p<0.001, and r=+0.61; p<0.001, respectively.These findings suggest that, compared with the Mediterranean diet, dietary acid load decreased significantly on the low-fat vegan diet and was associated with weight loss. The alkalizing effect of a vegan diet may be an independent mechanism by which a vegan diet promotes weight loss.

Keywords: ClinicalTrials.gov number, NCT03698955 Dietary acid load, Mediterranean, nutrition, plant-based, vegan PRAL, NAEP

Received: 23 May 2025; Accepted: 11 Jun 2025.

Copyright: © 2025 Kahleova, Maracine, Himmelfarb, Jayaraman, Znayenko- Miller, Holubkov and Barnard. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Hana Kahleova, Physicians Committee for Responsible Medicine, Washington D.C., United States

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