The Nutri-Score is a voluntary label, in use in several European countries, that rates foods on a scale from A to E based on their nutritional composition. The calculation is based, among other things, on energy, sugar, saturated fatty acids and salt, as well as positively rated components such as fibre and protein. Because the calculation refers to 100 g or 100 ml, concentrated products such as powders can sometimes score differently from ready-to-drink beverages.
For high-protein products such as protein powder or protein bars, this means that a high protein content can have a positive effect, but sugar, fat and calorie content also feed into the rating. A good Nutri-Score therefore says nothing about the protein content alone, but about the overall nutritional composition of a product. The Nutri-Score therefore does not replace a look at the full nutrition table and the ingredient list.
How to read an ingredient list in addition to the Nutri-Score is explained in the entry Ingredient list, and more on comparing different powders is offered by the guide Protein powders compared.
