Group 1
Unprocessed
Whole ingredients in roughly the form you'd find them in nature.
eggs · tomatoes · oats · chicken · lentils
The science behind the score
Why processing matters - even when the nutrient numbers look fine.
NOVA does not score nutrients; it scores the degree of industrial processing a food has undergone. It is one of the core reasons Nutrons looks beyond calories and macros when evaluating food quality.
01 /NOVA Classification
Four groups. One clear processing gradient.
Developed at the University of Sao Paulo, NOVA groups foods by how far they have been transformed from their original structure. Group 4 is where health risk signal is most consistent across large population studies.
Group 2
Culinary ingredients
Extracted or refined for cooking. Not really eaten alone.
olive oil · flour · butter · salt · sugar
Group 3
Processed foods
Group 1 ingredients preserved or transformed using Group 2 ingredients.
tinned fish · aged cheese · cured meats · sourdough
Group 4
Ultra-processed
Industrial formulations containing additives with no culinary equivalent.
protein bars · shop-bought bread · flavoured yoghurts
Key finding - Hall et al., NIH 2019
Two diets matched for calories, macros, fibre, and sugar on paper. The ultra-processed arm still consumed around 500 extra calories per day and gained weight.
Same nutrient profile, very different outcomes. The question is not only what is in a food, but what has been done to it.
What researchers think is happening
Food matrix disruption
Whole foods have physical structure - cell walls, fibre networks, water content - that slows absorption and signals fullness. Industrial processing dismantles this.
Additives & the microbiome
Some emulsifiers and preservatives have been shown to disrupt gut bacteria populations and gut lining integrity. The human evidence is still developing, but the pathway is credible.
Hyper-palatability
Foods engineered to hit precise fat, salt, sugar, and texture combinations can override normal satiety feedback loops. Not a willpower failure - a calibration problem.
Eating rate
Ultra-processed foods tend to be softer, pre-broken-down. People eat them faster - outpacing the hormonal signals that register fullness.