Association of Dietary Factors with Nephrolithiasis: A Systematic Review and Meta-Analysis

Background: Nephrolithiasis is a highly prevalent condition heavily influenced by dietary habits. While individual nutrients have been extensively studied, comprehensive evaluations of broad dietary patterns remain fragmented. This systematic review and meta-analysis aims to quantify the risk of nephrolithiasis across eight distinct nutritional domains. Methods: Following PRISMA 2020 guidelines, we systematically searched electronic databases, including PubMed and Scopus (up to May 2026), to identify studies investigating the association between dietary factors and the risk of nephrolithiasis. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted. Pooled estimates were calculated using random-effects models, with heterogeneity assessed via the I2 statistic and publication bias evaluated using Egger’s test. Results: We synthesized data from 61 unique observational studies. High fluid volume and specific beverages, including coffee, tea, and moderate alcohol, demonstrated strong protective effects. A plant-forward dietary pattern—encompassing high intake of fruits, vegetables, dietary fiber, and adherence to the Dietary Approaches to Stop Hypertension (DASH) diet—was significantly associated with reduced stone risk. Furthermore, dairy products and dietary calcium conferred significant protection, supporting the intestinal oxalate-binding mechanism. Conversely, nephrolithiasis risk was significantly elevated by high consumption of meat, sugar-sweetened beverages, and ultra-processed foods. Metrics of high dietary acid load, specifically net endogenous acid production, strongly correlated with increased risk. Sensitivity analyses restricted exclusively to high-quality prospective cohorts confirmed the robust protective effects of fruit, dairy, coffee, dietary calcium and the DASH diet, alongside the elevated risk associated with sodium and sugar-sweetened beverages. Conclusions: Diet plays a profound role in the pathogenesis of nephrolithiasis. Nutritional strategies for stone prevention should transition beyond single-nutrient restrictions toward holistic dietary patterns. A regimen prioritizing adequate hydration, plant-based foods, and dairy, while strictly limiting animal meat, refined sucrose, and systemic acid loads, provides robust protection against stone formation.