The effect of dietary nitrate on weight management: a systematic review and meta-analysis

Background Obesity has emerged as a significant global public health concern. Despite its potential therapeutic benefits, the existing evidence regarding dietary nitrate supplementation remains inconclusive. This systematic review and meta-analysis aimed to evaluate the effects of dietary nitrate intake on obesity-related outcomes. Methods A comprehensive search of randomized controlled trials (RCTs) investigating nitrate supplementation in adults with obesity was conducted across PubMed, Scopus, Web of Science, and Embase up to April 2026. The primary outcomes included body weight, body mass index (BMI), blood pressure, and lipid-related markers. The study adhered to the PRISMA 2020 guidelines for reporting. Results Eight RCTs involving 199 participants were included in the meta-analysis. No significant effects of nitrate supplementation were observed on body weight, BMI, or diastolic blood pressure (DBP). A statistically significant reduction was observed in systolic blood pressure (SBP, 95% CI: −0.63 to −0.01; SMD = −0.32, p = 0.04; I 2 = 41%). In addition, dietary nitrate supplementation was associated with significant reductions in total cholesterol (TC, 95% CI: −1.11 to −0.06; SMD = −0.59, p = 0.03; I 2 = 50%) and triglycerides (TG, 95% CI: −0.81 to −0.09; SMD = −0.45, p = 0.01; I 2 = 0%). Subgroup analysis stratified by intervention duration revealed no significant interaction effects for either SBP or DBP (all P for interaction > 0.05). Publication bias was detected for BMI and DBP. Conclusion Dietary nitrate supplementation exerts favorable effects on lipid parameters and systolic blood pressure, with no remarkable impacts on body weight and BMI observed. Given the relatively small sample size of the included evidence, future large-sample, high-quality, long-term randomized controlled trials are essential to confirm and reinforce the present results. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/ , CRD420251078542.