How the Clean Score works
Version 1 · 19 October 2026 · This page is the whole method. Nothing is hidden or weighted behind the scenes.
Every product starts at 100. Points come off for how processed it is, the additives in it, its sugar, fat and salt, and anything on your personal avoid list. The score cannot go below 0. Each deduction is listed on the product page under "How this score is worked out".
What the score means
75 to 100
Clean
Clean
50 to 74
Okay
Okay
25 to 49
Poor
Poor
0 to 24
Avoid
Avoid
The four bands follow the convention used by Yuka, so the numbers read the same way people already expect.
The rules
| Rule | Points | Why |
|---|---|---|
| Ultra-processed (NOVA group 4) | −40 | The largest umbrella review to date found convincing evidence linking higher ultra-processed food intake to cardiovascular death and type 2 diabetes [1]. In a controlled trial, people ate about 500 kcal a day more on an ultra-processed diet [2]. |
| Processed (NOVA 3) | −15 | Foods made by adding salt, sugar or oil to whole foods, e.g. cheese, tinned fish, simple bread [3]. |
| Lightly processed (NOVA 2) | −5 | Culinary ingredients such as oils, butter and sugar [3]. |
| No NOVA group published, but the ingredients contain an ultra-processing marker | treated as −40 | NOVA's own identification rule: one marker is enough, such as a sweetener, colour, flavouring, emulsifier, thickener, glucose syrup, maltodextrin, hydrogenated oil or protein isolate [3]. |
| High-risk additive, each | −25 | Additives classed as probably or possibly carcinogenic, or withdrawn in the EU. Examples: nitrites in cured meat (processed meat is IARC Group 1), titanium dioxide (E171, banned in the EU since 2022), BHA (E320). |
| Moderate-risk additive, each | −15 | Additives with credible human or animal evidence of harm, or official advice against routine use. Examples: artificial sweeteners (WHO advises against using them for weight control [4]; aspartame is IARC Group 2B [5]; a cohort of 102,865 adults linked aspartame and acesulfame K with higher cancer risk [6]), caramel colours E150c and E150d, phosphoric acid, and emulsifiers linked to cardiovascular disease in a large cohort [7]. |
| Low-risk additive, each | −3 | Approved additives with little evidence of harm at normal intake, e.g. xanthan gum, lecithin. |
| Additive with no known risk | 0 | E.g. citric acid, vitamin C, natural colours from vegetables. |
| High sugar, saturated fat, salt or fat, each | −10 | UK front-of-pack "red" thresholds per 100g: sugar over 22.5g, saturates over 5g, salt over 1.5g, fat over 17.5g. Drinks use half these values per 100ml [8]. |
| Medium sugar, saturated fat, salt or fat, each | −3 | UK "amber" thresholds [8]. |
| Added sugar in the ingredients | −10 | WHO advises keeping free sugars below 10% of energy, ideally 5% [9]. |
| High fibre (6g or more per 100g) | +5 | Meets the UK "high fibre" claim threshold. Fibre is consistently linked with lower disease risk [10]. |
| On your personal avoid list, each | −15 | Your choice, shown separately in purple. Not an evidence rule. |
| Contains one of your allergens | score 0 | Safety comes first. |
| No ingredient list available | no score | We never call a product clean when we cannot see what is in it. The app asks you to photograph the label instead. |
Worked example: Diet Coke
Start100
Ultra-processed (NOVA 4)−40
Sulphite ammonia caramel (E150d), moderate−15
Phosphoric acid (E338), moderate−15
Aspartame (E951), moderate−15
Acesulfame K (E950), moderate−15
Citric acid (E330), no known risk0
Sugar, fat and salt all low0
Clean Score (floor 0)0 · Avoid
For comparison, plain organic porridge oats lose nothing and score 100.
What we deliberately do not count
- Seed oils. Some apps penalise sunflower, rapeseed and other seed oils. Current evidence does not support this: higher linoleic acid intake is linked with lower, not higher, heart disease risk. The app shows when a product contains seed oils, and you can add them to your avoid list, but they do not come off the score by default.
- Calories. Energy is tracked separately in your food log. A low-calorie product is not automatically a clean one.
- Organic status. It changes pesticide exposure, which is shown separately as an estimate, not in the score.
Limits, honestly
- Product data comes from Open Food Facts, which is crowd-sourced. Some listings are incomplete or wrong. When a listing is empty we use a complete listing of the same product, or read a photo of the label, and say so on the page.
- Additive risk tiers are our reading of public assessments by EFSA, IARC, WHO and the UK FSA. They are not medical advice. The tiers will be reviewed and this page versioned when they change.
- Pesticide, microplastic and heavy metal levels are estimated from product category, packaging and labels. They are not lab tests and are not part of the score.
- The score is about the product, not your whole diet. A low score means "worth swapping where you can", not "dangerous".
Sources
- Lane MM et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ 2024;384:e077310. bmj.com
- Hall KD et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial. Cell Metabolism 2019;30:67–77. pubmed
- Monteiro CA et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutrition 2019;22(5):936–941. pubmed
- World Health Organization. Use of non-sugar sweeteners: WHO guideline. 2023. who.int
- IARC and JECFA. Aspartame hazard and risk assessment results released. 14 July 2023. who.int
- Debras C et al. Artificial sweeteners and cancer risk: results from the NutriNet-Santé population-based cohort study. PLOS Medicine 2022;19(3):e1003950. plos.org
- Sellem L et al. Food additive emulsifiers and risk of cardiovascular disease in the NutriNet-Santé cohort. BMJ 2023;382:e076058. bmj.com
- Department of Health and Social Care and Food Standards Agency. Guide to creating a front of pack nutrition label for pre-packed products sold through retail outlets. 2016. gov.uk
- World Health Organization. Guideline: sugars intake for adults and children. 2015. who.int
- Reynolds A et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet 2019;393:434–445. pubmed
Clean Calorie gives general information, not medical advice. Questions or corrections: use the contact form on cleancalorie.app.