Body mass index

Method

Body mass in kilograms divided by standing height in metres squared, from measured rather than self-reported values, at a stated timepoint.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

The most frequently reported anthropometric endpoint in this corpus and, until 2026-08-19, absent from the vocabulary entirely — twenty-one papers reported it against nowhere to put it. Kept separate from body-mass and from fat-mass rather than derived: a ratio moves when either of its inputs moves, so a trial that shifts one and not the other reports something neither of the other two nodes can express. Self-reported height and mass bias this downward and the source of the values is recorded on the edge.

Findings

5 findings from 3 compounds, strongest first.

• melatonin — no detected effect on

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.FindingNull result

  “The results of random-effect meta-analysis indicated that melatonin intake has no effect on weight (SMD: −0.03, 95% CI: −0.30, 0.25, I2 = 00.00%) and BMI (SMD: −0.03, 95% CI: −0.30, 0.25, I2 = 00.00%) in patients with PCOS (Fig..).”

  Study

  meta-analysis

  Dose

  3-10 mg/day oral

  Population

  women with polycystic ovary syndrome; 6 double-blind RCTs

  Effect -0.03 standardised mean difference, 95% CI -0.3 to 0.25

  Effect of melatonin supplementation on cardiometabolic risk factors, oxidative stress and hormonal profile in PCOS patients: a systematic review and meta-analysis of randomized clinical trials.2024PMID:38965577

• curcumin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×2

  “Thirteen studies assessed reduction of BMI indicating curcumin supplementation was effective in lowering BMI with MD (95% CI) of −0.34 (−0.62, −0.05) kg/m2; I2 = 62.7%, see Supplementary Appendix Q.”

  Study

  meta-analysis

  Dose

  80–3000 mg/day pooled across bioavailability-enhanced forms (80–1000 mg/day), curcumin extracts (1500 mg/day) and turmeric powder (2000–3000 mg/day)

  Population

  Adults with MAFLD (NAFLD/NASH); 13 RCTs; BMI was an additional (secondary) outcome of this review

  Effect -0.34 mean difference, 95% CI -0.62 to -0.05

  An updated meta-analysis of effects of curcumin on metabolic dysfunction-associated fatty liver disease based on available evidence from Iran and Thailand.2023PMID:37037891

• nitrate — no detected effect on

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.FindingNull result

  “No significant effects of nitrate supplementation were observed on body weight, BMI, or diastolic blood pressure (DBP).”

  Study

  meta-analysis

  Population

  adults with obesity

  The effect of dietary nitrate on weight management: a systematic review and meta-analysis.2026PMID:42130877

• curcumin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×2

  “The results showed that curcumin reduced BMI compared with placebo [weighted mean difference (WMD) = -0.49, 95% CI (-0.81, -0.18), P = 0.002].”

  Study

  meta-analysis

  Participants

  462

  Population

  adults with non-alcoholic fatty liver disease

  Effect -0.49 mean difference, 95% CI -0.81 to -0.18

  Efficacy and safety of dietary polyphenol supplementation in the treatment of non-alcoholic fatty liver disease: A systematic review and meta-analysis.2022PMID:36159792

• curcumin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×2

  “Anthropometric measurements, including BMI and WC, were significantly lower in the curcumin group compared to the placebo group at 3, 6, 9, and 12 months ( Table 4; B).”

  Study

  RCT

  Duration

  12 months

  Dose

  Oral ethanolic Curcuma longa rhizome extract standardised to 75-85% total curcuminoids, 250 mg curcuminoids per capsule, three capsules twice daily (1500 mg curcuminoids/day) for 12 months

  Population

  Obese adults with type 2 diabetes mellitus managed on metformin (age >=35 y, BMI >=23 kg/m2, HbA1c <6.5%), Nakhon Nayok, Thailand; 227 randomised, per-protocol analysis and the analysed count is not reported in the paper; this outcome is named in neither the declared primary nor the declared secondary endpoint list (declared primary outcome: liver steatosis by controlled attenuation parameter); BMI by bioelectrical impedance analyser (Omron HBF-362)

  Curcumin Attenuates Liver Steatosis via Antioxidant and Anti-Inflammatory Pathways in Obese Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial.2025PMID:41096556Industry funded