Methodology

How NutriDécrypte computes every grade

Every product receives a single A to E grade composed from five weighted axes. No human judgement, no sponsor influence, no black-box AI. The algorithm is deterministic and reproducible: same ingredient list, same grade.

The A to E grade at a glance

A

Excellent85-100

B

Good70-84

C

Average55-69

D

Poor40-54

E

Avoid0-39

The five weighted axes

Each axis is scored from 0 to 100, then multiplied by its weight. The five contributions are summed to produce the final score.

01
25% of final score

Nutri-Score (official)

We use the official Nutri-Score published by Santé publique France as the nutritional backbone. It captures the balance of positive nutrients (fiber, protein, fruits/vegetables) against negative ones (saturated fat, sugar, salt). We map A through E to a 0-100 scale, A = 95, E = 15.

02
25% of final score

NOVA ultra-processing class

The NOVA classification (University of São Paulo) ranks foods from 1 (unprocessed) to 4 (ultra-processed). It is the single strongest predictor of long-term metabolic risk, independent of macronutrients. NOVA 1 scores 95 here; NOVA 4 drops to 20.

03
20% of final score

Additive risk (EFSA)

Every E-number is cross-referenced against the EFSA food additives database and the latest ANSES opinions. Each additive carries a risk score from 0 (neutral) to 3 (to avoid). A product with zero additives starts at 100, with heavy penalties applied by risk bucket.

04
15% of final score

Marketing claims audit

Every front-of-pack claim ('natural', 'source of', 'free from') is audited against the actual ingredient list. Honest claims pass without penalty. Stretched claims (technically true, practically misleading) deduct 12 points. Outright misleading claims deduct 30. This axis is what makes the NutriDécrypte grade different from a nutrition score.

05
15% of final score

Nutritional density

Measures how much real nutrition the product delivers per 100 g: protein and fiber push the score up, excess sugar, saturated fat, and sodium pull it down. When a micronutrient density index is available (iron, calcium, B vitamins), it replaces the formula.

Full formula

Score = 25% · Nutri-Score
      + 25% · NOVA
      + 20% · Additifs EFSA
      + 15% · Allégations
      + 15% · Densité

Weights are public. Any change is versioned and announced in the journal. Same composition = same grade. You can recompute any grade by hand from the sub-scores shown on each product page.

Our official sources

  • Open Food Facts Collaborative database of 3 million European products, ODbL licence.
  • EFSA European Food Safety Authority, additives database, scientific opinions.
  • ANSES French national food safety agency, nutrition reports, risk opinions.
  • NOVA Food classification by degree of processing, University of São Paulo.
  • Nutri-Score Official FR nutrition logo, Santé publique France.
  • data.gouv.fr Nutrition and food safety datasets, INCA 3, CIQUAL.

What we do NOT do

  • No payment to change a grade : brands cannot buy their way up, ever.
  • No opaque scoring : every axis, weight, and penalty is visible on every product page.
  • No moral judgement : we rate a composition against official sources, not a brand, a packaging, or a lifestyle.
  • No medical advice : our grades are informational. For any nutritional condition, consult a registered dietitian or physician.

Updates and revisions

Our product database is synchronized with Open Food Facts every week. When a brand changes its formulation or an EFSA / ANSES opinion revises an additive, affected grades are recomputed automatically. The algorithm revision history is public.