How we score foods
Every Food Index score comes from 19 evidence-weighted factors applied to USDA nutrition data. This page sets out the data we use, each factor and its weight, a real worked example, and the 24 studies and guidelines the weights come from.
1,528 foods scored · Methodology version 1.1
How a score is built
From data to score
Data sources
USDA FNDDS food and nutrient tables, plus purine values from the research literature where they have been measured directly.
Purine estimation
Each food gets a purine figure. Where a food has been measured in a laboratory we use that value; otherwise we use the typical value for foods like it. How we got the figure sets the confidence rating.
Evidence-weighted scoring
19 factors apply as penalties and bonuses, each weighted by the strength of the clinical evidence behind it.
The finished score
A 0–100 score with its band, separate flare-risk and long-term figures, a confidence rating, and the full factor breakdown.
Factor groups
What we measure
The 19 factors fall into five groups. The weight shown is the most any group can move a score.
Purine load
The purine content a food delivers, adjusted for its source. Animal and seafood purines raise urate far more than plant purines, and the effect is sharper when purines arrive alongside alcohol.
Alcohol and fructose
Alcohol slows the clearance of urate, and fructose produces urate directly when the body breaks it down. These are the two strongest routes to gout that do not involve purines.
Food category and density
Some categories carry direct epidemiological evidence of their own, over and above their nutrients. Energy-dense foods with few protective nutrients are marked down.
Fats, sodium and iron
Saturated fat and sodium both affect insulin resistance and how well the kidneys clear urate. Heme iron, found only in animal foods, activates the enzyme that produces uric acid.
Protective nutrients
Low-fat dairy protein, vitamin C, fiber, coffee, omega-3, cherries, hydration, folate and magnesium all add points back. Together they are capped at +18, so no food can score as risk-free on protective nutrients alone.
Worked example
Scoring chicken fillet, grilled
Each row is the real arithmetic behind this food's score. Step through it from the top.
Every food starts at 100
The score is top-down: a food begins at a perfect 100 and only moves when a factor with published evidence behind it applies.
Every food page shows this same breakdown for its own score. See it on Chicken fillet, grilled.
Research foundation
The evidence base
All 24 studies and guidelines behind the factor weights, newest first.
24
Studies and guidelines
14
Rated strong evidence
2004–2021
Publication span
31
Links between a factor and a source
The role of diet in hyperuricemia and gout
Yokose C, McCormick N, Choi HK · 2021 · Curr Opin Rheumatol
Dietary patterns (DASH, Mediterranean) more important than individual foods. Alcohol and fructose strongest dietary risk factors.
2020 American College of Rheumatology Guideline for Management of Gout
FitzGerald JD, Dalbeth N, Mikuls T, et al. · 2020 · Arthritis Care Res
ACR conditionally recommends limiting alcohol (especially beer), organ meats, and high-fructose corn syrup.
Effect of dietary and supplemental omega-3 polyunsaturated fatty acids on risk of recurrent gout flares
Zhang M, Zhang Y, Terkeltaub R, Chen C, Neogi T · 2019 · Arthritis Rheumatol
Higher omega-3 intake reduces gout flare risk; protective effect offsets purine content in fatty fish.
Dietary factors and risk of gout and hyperuricemia: a meta-analysis and systematic review
Li R, Yu K, Li C · 2018 · Asia Pac J Clin Nutr
Confirms meat, seafood, and alcohol as risk factors; dairy protective. Largest pooled estimate to date.
Evaluation of the diet wide contribution to serum urate levels
Major TJ, Topless RK, Dalbeth N, Merriman TR · 2018 · BMJ
Diet explains very small proportion of SUA variance; genetics dominates. But acute triggers still matter for flares.
The British Society for Rheumatology Guideline for the Management of Gout
Hui M, Carr A, Cameron S, et al. · 2017 · Rheumatology
BSR advises limiting purine-rich foods, alcohol, and fructose; emphasizes dairy and vitamin C as protective.
A case-control study of the association of diet and obesity with gout in Taiwan
Lyu LC, Hsu CY, Yeh CY, Lee MS, Huang SH, Chen CL · 2017 · Am J Clin Nutr
Higher dietary folate intake significantly associated with lower serum uric acid levels.
2016 updated EULAR evidence-based recommendations for the management of gout
Richette P, Doherty M, Pascual E, et al. · 2017 · Ann Rheum Dis
EULAR advises avoiding alcohol (especially beer), sugar-sweetened beverages, and excessive meat/seafood.
Effects of the Dietary Approaches to Stop Hypertension (DASH) Diet on serum uric acid
Juraschek SP, Gelber AC, Choi HK, Appel LJ, Miller ER · 2016 · Arthritis Rheumatol
DASH diet significantly lowers uric acid, especially in those with hyperuricemia. Fiber, dairy, and plant-focus contribute.
Serum uric acid levels and multiple health outcomes: umbrella review of evidence from observational studies, randomised controlled trials, and Mendelian randomisation studies
Li X, Meng X, Timofeeva M, et al. · 2015 · BMJ
Genetically predicted higher magnesium levels associated with lower gout risk via MR analysis.
Body mass index and the risk of gout: a systematic review and dose-response meta-analysis
Aune D, Norat T, Vatten LJ · 2014 · Eur J Nutr
Obesity is an independent gout risk factor; calorie-dense foods contribute indirectly through weight gain.
Total purine and purine base content of common foodstuffs for facilitating nutritional therapy for gout and hyperuricemia
Kaneko K, Aoyagi Y, Fukuuchi T, Inazawa K, Yamaoka N · 2014 · Biol Pharm Bull
Comprehensive purine profiling of 270 foods; organ meats and certain seafood highest; dairy and eggs negligible.
Relation of temperature and humidity to the risk of recurrent gout attacks
Neogi T, Chen C, Niu J, Chaisson C, Hunter DJ, Zhang Y · 2014 · Am J Epidemiol
Adequate water intake (8+ glasses) reduces gout flare risk by nearly half.
Effects of dairy intake on hyperuricemia and gout
Dalbeth N, Palmano K · 2012 · Curr Rheumatol Rep
Orotic acid and casein/lactalbumin in dairy promote uric acid excretion; multiple mechanisms confirmed.
Cherry consumption and decreased risk of recurrent gout attacks
Zhang Y, Neogi T, Chen C, Chaisson C, Hunter DJ, Choi HK · 2012 · Arthritis Rheum
Cherry consumption over 2 days reduced gout flare risk by 35%; effect additive with allopurinol.
Purine-rich foods intake and recurrent gout attacks
Zhang Y, Chen C, Choi H, et al. · 2012 · Ann Rheum Dis
Acute purine intake triggers flares in a dose-response manner within 2 days.
Effect of oral vitamin C supplementation on serum uric acid: a meta-analysis of randomized controlled trials
Juraschek SP, Miller ER, Gelber AC · 2011 · Arthritis Care Res
Vitamin C supplementation modestly but significantly reduces serum uric acid levels.
Fructose-rich beverages and risk of gout in women
Choi HK, Willett W, Curhan G · 2010 · JAMA
Fructose-rich beverages increase gout risk in women; effect confirmed across sexes.
Acute effect of milk on serum urate concentrations: a randomised controlled crossover trial
Dalbeth N, Wong S, Gamble GD, et al. · 2010 · Ann Rheum Dis
Dairy protein (especially skim milk) acutely lowers serum uric acid via uricosuric effect.
Vitamin C intake and the risk of gout in men: a prospective study
Choi HK, Gao X, Curhan G · 2009 · Arch Intern Med
Higher vitamin C intake strongly associated with lower gout risk, likely via uricosuric effect.
Soft drinks, fructose consumption, and the risk of gout in men
Choi HK, Curhan G · 2008 · BMJ
Sugar-sweetened soft drink consumption strongly associated with gout risk; diet drinks showed no association.
Coffee, tea, and caffeine consumption and serum uric acid level
Choi HK, Curhan G · 2007 · Arthritis Rheum
Coffee consumption inversely associated with uric acid and gout risk; effect independent of caffeine.
Alcohol consumption as a trigger of recurrent gout attacks
Zhang Y, Woods R, Chaisson CE, et al. · 2006 · Am J Med
Beer and spirits significantly trigger gout flares; wine shows no significant association in moderate amounts.
Purine-rich foods, dairy and protein intake, and the risk of gout in men
Choi HK, Atkinson K, Karlson EW, Willett W, Curhan G · 2004 · N Engl J Med
Higher meat and seafood intake significantly increases gout risk; dairy intake is strongly protective.
Our promise
Transparency commitment
Open methodology
Every factor, its weight and its rationale is published on this page. The score is a documented formula, not a proprietary rating.
Traceable data
Nutrition values come from the USDA database, and each factor links to the studies behind its weight. Every food page shows the working for its own score.
No outside influence
No company has paid to influence a score or a factor weight, and none will.
Common questions
Frequently asked questions
Reference
Factors and sources in full
All 19 factors with their exact weights, and the 24 sources in citation form.
The 19 scoring factors
Every food starts at 100. 10 penalties pull the score down for known risk factors, and 9 bonuses add points back for protective ones. Each factor is weighted by the strength of the clinical evidence behind it.
Penalties (risk factors)
- Animal/Seafood Purinesup to −70 ptsFlare risk
Purines from meat and seafood are the strongest dietary driver of gout. The body breaks them down into uric acid, and each additional daily serving raises the risk of a flare.
Meat RR 1.41 and seafood RR 1.51 per serving (Choi 2004). Odds rise to 4.76 in the highest intake quintile (Zhang 2012).
- Category Surchargeup to −45 ptsBoth
A few food categories carry direct evidence of gout risk that their nutrient values alone do not capture, such as organ meats and beer. Those categories take an additional deduction.
- Alcoholup to −35 ptsFlare risk
Alcohol slows the rate at which the kidneys clear uric acid, and every clinical guideline advises limiting it. The penalty is scaled so the first drink counts for more than the fourth.
Beer OR 2.5 and spirits OR 1.60 for triggering a flare (Zhang 2006).
- Fructose (estimated)up to −35 ptsLong-term risk
Fructose is metabolised in a way that produces uric acid directly, so sugar-sweetened drinks raise gout risk despite containing no purines.
Sugar-sweetened drinks RR 1.85 in men (Choi 2008) and RR 2.39 in women (Choi 2010).
- Saturated Fatup to −12 ptsLong-term risk
Saturated fat contributes to insulin resistance, which reduces how much urate the kidneys excrete.
The DASH diet, low in saturated fat, lowers serum urate (Juraschek 2016).
- Synergy Penaltyup to −12 ptsFlare risk
Alcohol impairs the clearance of purines, so a food or drink that delivers both at once carries more short-term risk than either would alone.
- Calorie Densityup to −10 ptsLong-term risk
Obesity is an independent risk factor for gout, and energy-dense foods make weight gain more likely.
Gout risk RR 1.55 per 5 kg/m² of body mass index (Aune 2014).
- Nutrient Gapsup to −10 ptsLong-term risk
A food that supplies none of the protective nutrients (vitamin C, fibre, omega-3, magnesium, folate) offers nothing to offset its risk factors.
- Sodiumup to −8 ptsLong-term risk
Around three-quarters of people with gout also have high blood pressure, and excess sodium worsens both kidney function and urate handling.
- Heme Ironup to −5 ptsLong-term risk
Iron activates xanthine oxidoreductase, the enzyme that produces uric acid. Only the heme iron in animal foods is counted.
Causal link supported by Mendelian randomisation (Li 2018).
Bonuses (protective factors)
- Low-fat Dairy Proteinup to +10 ptsBoth
Low-fat dairy is the most consistently protective food group in gout research. Orotic acid and the milk proteins casein and lactalbumin all help the kidneys pass uric acid out.
RR 0.56 (Choi 2004), confirmed in controlled trials (Dalbeth 2010, 2012).
- Vitamin Cup to +6 ptsLong-term risk
Vitamin C is uricosuric, meaning it increases the amount of uric acid the kidneys excrete.
RR 0.55 at 500 mg or more a day (Choi 2009). Pooled reduction of 0.35 mg/dL across 13 trials (Juraschek 2011).
- Fiberup to +5 ptsLong-term risk
Fibre improves insulin sensitivity, and high-fibre eating patterns lower serum urate.
Serum urate falls by 0.35 to 1.29 mg/dL on the DASH diet (Juraschek 2016).
- Coffeeup to +4 ptsLong-term risk
Regular coffee drinking is associated with lower gout risk, and the effect does not appear to come from caffeine.
RR 0.41 to 0.60 at four or more cups a day (Choi 2007).
- Omega-3 (EPA+DHA)up to +4 ptsFlare risk
EPA and DHA are anti-inflammatory and appear to offset part of the purine load in oily fish.
Adjusted OR 0.74 in the highest intake tertile (Zhang 2019).
- Cherry/Berryup to +3 ptsFlare risk
Cherries and berries contain anthocyanins that reduce inflammation, and cherry intake is linked to fewer recurrent flares.
OR 0.65 for flare risk (Zhang 2012).
- Hydrationup to +3 ptsFlare risk
Water dilutes serum urate, and people who drink enough of it report substantially fewer flares.
46% fewer flares with adequate water intake (Neogi 2014).
- Folateup to +2 ptsLong-term risk
Folate may inhibit xanthine oxidase, the enzyme that generates uric acid.
Serum urate 57.6 µmol/L lower in the highest intake tertile (Lyu 2017).
- Magnesiumup to +2 ptsLong-term risk
Magnesium supports the kidneys in excreting uric acid.
OR 0.630 per standard deviation in Mendelian randomisation (Li 2015).
Reference list
All 24 sources in citation form: cohort studies, trials, meta-analyses and the ACR, EULAR and BSR gout guidelines.
Risk factors
- Purine-rich foods, dairy and protein intake, and the risk of gout in menChoi HK, Atkinson K, Karlson EW, Willett W, Curhan G, 2004, N Engl J Medstrong
- Alcohol consumption as a trigger of recurrent gout attacksZhang Y, Woods R, Chaisson CE, et al., 2006, Am J Medstrong
- Soft drinks, fructose consumption, and the risk of gout in menChoi HK, Curhan G, 2008, BMJstrong
- Fructose-rich beverages and risk of gout in womenChoi HK, Willett W, Curhan G, 2010, JAMAstrong
- Purine-rich foods intake and recurrent gout attacksZhang Y, Chen C, Choi H, et al., 2012, Ann Rheum Disstrong
- Body mass index and the risk of gout: a systematic review and dose-response meta-analysisAune D, Norat T, Vatten LJ, 2014, Eur J Nutrstrong
- Dietary factors and risk of gout and hyperuricemia: a meta-analysis and systematic reviewLi R, Yu K, Li C, 2018, Asia Pac J Clin Nutrstrong
Protective factors
- Coffee, tea, and caffeine consumption and serum uric acid levelChoi HK, Curhan G, 2007, Arthritis Rheummoderate
- Vitamin C intake and the risk of gout in men: a prospective studyChoi HK, Gao X, Curhan G, 2009, Arch Intern Medstrong
- Acute effect of milk on serum urate concentrations: a randomised controlled crossover trialDalbeth N, Wong S, Gamble GD, et al., 2010, Ann Rheum Dismoderate
- Effect of oral vitamin C supplementation on serum uric acid: a meta-analysis of randomized controlled trialsJuraschek SP, Miller ER, Gelber AC, 2011, Arthritis Care Resmoderate
- Effects of dairy intake on hyperuricemia and goutDalbeth N, Palmano K, 2012, Curr Rheumatol Repmoderate
- Cherry consumption and decreased risk of recurrent gout attacksZhang Y, Neogi T, Chen C, Chaisson C, Hunter DJ, Choi HK, 2012, Arthritis Rheummoderate
- Relation of temperature and humidity to the risk of recurrent gout attacksNeogi T, Chen C, Niu J, Chaisson C, Hunter DJ, Zhang Y, 2014, Am J Epidemiolmoderate
- Serum uric acid levels and multiple health outcomes: umbrella review of evidence from observational studies, randomised controlled trials, and Mendelian randomisation studiesLi X, Meng X, Timofeeva M, et al., 2015, BMJmoderate
- Effects of the Dietary Approaches to Stop Hypertension (DASH) Diet on serum uric acidJuraschek SP, Gelber AC, Choi HK, Appel LJ, Miller ER, 2016, Arthritis Rheumatolstrong
- A case-control study of the association of diet and obesity with gout in TaiwanLyu LC, Hsu CY, Yeh CY, Lee MS, Huang SH, Chen CL, 2017, Am J Clin Nutrweak
- Effect of dietary and supplemental omega-3 polyunsaturated fatty acids on risk of recurrent gout flaresZhang M, Zhang Y, Terkeltaub R, Chen C, Neogi T, 2019, Arthritis Rheumatolmoderate
Guidelines and reviews
- Total purine and purine base content of common foodstuffs for facilitating nutritional therapy for gout and hyperuricemiaKaneko K, Aoyagi Y, Fukuuchi T, Inazawa K, Yamaoka N, 2014, Biol Pharm Bullstrong
- The British Society for Rheumatology Guideline for the Management of GoutHui M, Carr A, Cameron S, et al., 2017, Rheumatologystrong
- 2016 updated EULAR evidence-based recommendations for the management of goutRichette P, Doherty M, Pascual E, et al., 2017, Ann Rheum Disstrong
- Evaluation of the diet wide contribution to serum urate levelsMajor TJ, Topless RK, Dalbeth N, Merriman TR, 2018, BMJstrong
- 2020 American College of Rheumatology Guideline for Management of GoutFitzGerald JD, Dalbeth N, Mikuls T, et al., 2020, Arthritis Care Resstrong
- The role of diet in hyperuricemia and goutYokose C, McCormick N, Choi HK, 2021, Curr Opin Rheumatolmoderate