Nutri-Score: what does that A to E actually tell you?
Nutri-Score compresses several parts of a food’s nutritional composition into one simple letter. Useful – as long as you know what that letter means, and what it does not.
In Europe you increasingly see a Nutri-Score on food packaging: five letters, from a dark green A to an orange-red E.
At first glance it looks like a health grade. A must mean healthy, E must mean unhealthy – right?
Yes, but it is computed within a category: so olive oil and apple can both have a score of “A”, but that does not mean that both are “equally healthy”, or that you can consume both in the same quantities.
Nutri-Score is better understood as a quick comparison tool. It looks at several characteristics of a food together and gives them a combined score. The result can help you compare products of a similar kind without having to study every number on the nutrition label.
That makes it useful. But a single letter can never tell the whole story of a food – let alone your whole diet.
What goes into a Nutri-Score?
The calculation balances nutritional characteristics that generally count against a product with characteristics that count in its favor.
The current Nutri-Score algorithm considers, among other things:
Factors that can lower the rating:
- energy
- sugars
- saturated fat
- salt
Factors that can improve the rating:
- fibre
- protein
- fruit
- vegetables
- legumes
These are combined into a numerical score, which is then translated into a grade from A to E.
So the letter is not based on one nutrient. A food that contains a fair amount of fat, for example, is not automatically given a poor score. Its fibre, protein and ingredients may change the overall result.
Likewise, a product low in fat is not automatically an A.
A does not mean “eat as much as you like”
This is probably the most important thing to understand about Nutri-Score.
An A is not a certificate that a food is healthy in every possible sense, and an E is not a warning that the food must never be eaten.
The Dutch government describes Nutri-Score as a way to identify a product with a better nutritional composition compared with similar products.
That distinction matters.
If you are choosing between several breakfast cereals, pizzas or sauces, their Nutri-Scores can give you a useful shortcut. A cereal rated B has a nutritional composition that scores better under the system than a comparable cereal rated D.
But the letter does not answer every nutritional question you might have.
It does not tell you how much of the food you will eat. It does not know what else you ate today. It does not know whether you particularly need to watch your salt, increase your fibre or manage your carbohydrate intake.
For those questions, the underlying nutrition data still matters.
Compare like with like
Nutri-Score is most useful when you use it to compare foods that could realistically replace one another.
Compare one breakfast cereal with another. One frozen pizza with another. One yoghurt with another.
Comparing a bottle of olive oil with a soft drink simply because one has a different letter from the other does not tell you which belongs in a healthier diet.
This is also why apparently odd scores can sometimes make sense. A product that you would not normally describe as “healthy food” can still receive a relatively good Nutri-Score because, compared with similar products, its nutritional composition is better.
The reverse can happen too. A useful food can receive a C or D because it contains substantial saturated fat, salt or energy.
The score is answering a narrower question than “Is this food healthy?”
It is closer to:
“How does the nutritional composition of this product score within the Nutri-Score system?”
Why are there different Nutri-Score calculations?
There is not actually one identical formula applied blindly to every food.
The updated official algorithm has three main product categories:
- General foods
- Fats, oils, nuts and seeds
- Beverages
There are also specific rules within the general-food calculation, including rules for cheese and red meat.
That exists for a good reason. The nutritional profile of olive oil is fundamentally different from that of breakfast cereal, and a sensible scoring system needs to account for those differences. Drinks also behave differently from solid foods – even plain water has a special position in the beverage calculation.
So two products can contain similar amounts of an individual nutrient and still be treated differently because they belong to different Nutri-Score calculation categories.
This is another reason not to reverse-engineer too much meaning from the letter alone.
Why Log4Health calculates Nutri-Score
Log4Health often knows much more about a food than a single letter can show: its calories, macronutrients, fibre and sometimes micronutrients, ingredients and food groups.
So why show Nutri-Score at all?
Because compression is useful.
Sometimes you want the detail. Sometimes you just want a quick visual signal that says: this food has a more favourable or less favourable nutritional composition according to a recognised scoring method.
In Log4Health, Nutri-Score is therefore one view of the food – not a replacement for the rest of its nutritional information.
A C does not cancel out the fibre number sitting next to it. An A does not make the sugar or salt values irrelevant.
The interesting part is often the combination.
How Log4Health calculates it
Log4Health calculates Nutri-Score from the nutritional information it has for a food rather than relying only on a score supplied by a manufacturer.
The calculation follows the current Nutri-Score rules for the relevant type of food. Depending on the product, different parts of the official algorithm apply – for example the rules for general foods, fats, oils, nuts and seeds, or beverages.
For foods made from several ingredients, Log4Health can also use ingredient composition and food-group information when calculating the proportion of qualifying fruit, vegetables, legumes, nuts and related ingredients.
Alcoholic beverages are excluded from Nutri-Score calculation rather than being given a Nutri-Score.
There is one practical limitation worth remembering: a score can only be as good as the data behind it. If important nutritional information is missing, the calculated result may be incomplete. Log4Health keeps track of this where possible rather than pretending that missing data is the same thing as zero.
Use the letter, then look underneath it
Nutri-Score works best as a first glance rather than a final verdict.
If two similar products have very different grades, that is useful information. You can then look at why. Is one much saltier? Is the other higher in fibre? Does one contain considerably more sugar or saturated fat?
That is much more informative than turning A through E into five buckets labelled good through bad.
Food rarely works that way.
And neither does a diet.
Featured image attributed to: https://fr.openfoodfacts.org/ Public Domain, https://commons.wikimedia.org/w/index.php?curid=61695331
References
- Dutch Government – Questions and answers about Nutri-Score
- Dutch Government – Nutri-Score: comparing and choosing products
- Albert Heijn – Nutri-Score: kijk, vergelijk en kies
- Santé publique France – Nutri-Score
- Nutri-Score Wikipedia
- Open Food Facts’ Nutri-Score Implementation (github)
- Nutri-Score Algorithm for beverages (March 2022)
- Nutri-Score Algorithm Specification (July 2022)
