Table 3 Assessment of the updated Nutri-Score and its accordance with the Norwegian food-based dietary guidelines (FBDGs) [29, 31, 32]

Eat at least five portions of vegetables, fruit and berries every day.

Not including potatoes and legumes and nuts.

Vary between different fruit and vegetables.

Choose boiled and baked potatoes over fried.

Eat a handful of unsalted nuts every day.

One glass of juice can be one of the daily fruit and vegetable portions.

Over 80% of products in the fruit, vegetables and legumes category were classified with Nutri-Score A or B (Additional file 6). Comparing the distribution of Nutri-Score for the fruit, vegetables and legumes category to the other food categories, most products were clustered in Nutri-Score class A (Fig. 1 and Additional file 7). The fruit, vegetables and legumes component mainly allocated points within the fruit, vegetables and legumes category (Additional file 9).

In general, potato fries and potato products were classified with Nutri-Score C or D, whereas raw or boiled potatoes were classified with Nutri-Score A or B (Additional file 8).

Unsalted nuts were mainly classified with Nutri-Score A (82%) and most salted/coated nuts were classified with Nutri-Score C (46%) (Fig. 2 and Additional file 6).

Approximately half of juices (48%) were classified with Nutri-Score C (Additional files 6 and 8).

Eat whole grain foods every day.

Whole grain cereals/grains should provide 70–90 g wholegrain wheat or whole grain every day.

Choose grain products with a high content of fiber and whole grain, and low content of fat, sugar and salt.

Examples of food that can contribute with whole grain are breads, breakfast cereals, oat porridge, whole grain pasta or rice.

Cereals, grains and products thereof were distributed across all Nutri-Score classes (Additional files 5 and 7). A total of 51% of grains, pasta, rice and noodles were classified with Nutri-Score A (Additional file 6), but the Nutri-Score classes did not differentiate between whole grain and refined pasta or rice as both got Nutri-Score A (Additional file 8). Close to 60% of breads were classified with Nutri-Score A or B (Additional file 6).

Fiber was the component allocating the most favorable points, and variation in points, in the updated Nutri-Score for flour, flour mixes, breads and breakfast cereals (Additional file 9). Salt contributed with unfavorable points in breads, while sugars was influential among breakfast cereals.

There was a significant association between Nutri-Score and the Bread Scale, and more than 90% of the breads with 75–100% coarseness were classified with Nutri-Score A (Fig. 4 and Additional file 10).

Half of breakfast cereals were classified with Nutri-Score A or B (Additional file 6). Two out of 20 breakfast cereals with more than 10 g of sugars per 100 g were classified with Nutri-Score A (Additional file 8).

Sugary grain products, such as sweet biscuits/pastries, were mostly (85%) classified with D or E (Additional file 6), and sugars and saturated fat were the most influential components (Additional file 9).

Eat fish two to three times a week. You can also use fish as a sandwich topping.

Approximately 50% should be fatty fish (such as salmon, trout, mackerel, herring, eel, halibut, sardine).

Most (54%) fish products were classified with Nutri-Score A (Additional file 6). Both lean and fatty fish could be classified with Nutri-Score A (Additional file 8).

Choose lean meat and lean meat products. Limit the amount of processed meat and red meat.

Limit the amount of red meat and processed red meat to less than 500 g per week.

Choose poultry, lean meat and lean meat products that are low in salt.

Limit the amount of processed meat that are smoked, salted or preserved using nitrate or nitrite, such as bacon or cured sausage.

Overall, red meat products were classified with less favorable Nutri-Scores than poultry (Fig. 1), and 53% of red meat and 38% of poultry products were classified with Nutri-Score D or E (Additional file 6). However, lean red meat products could achieve Nutri-Score classes A and B. For red meat and poultry, saturated fat and salt were the components allocating the most unfavorable points, and variation in points, in the updated Nutri-Score (Additional file 9).

Red meat products classified with Nutri-Score A or B, were mainly raw, unprocessed meats (Additional file 8). In general, unprocessed and lean meats were more frequently classified in better Nutri-Score classes than processed and meats with higher fat content. Unprocessed meats from both red meat and poultry were generally classified with better Nutri-Scores than processed meats. Salted and preserved meats from both red meat and poultry, such as bacon and sausages were mainly classified with Nutri-Score D or E.

Include low-fat dairy foods in your daily diet.

Milk and cheese are commonly consumed, so choose the leaner options for everyday use.

Limit the use of dairy products containing high levels of saturated fat, such as whole milk, full-fat cream, full-fat cheese, and butter. Choose dairy products that are low in fat, salt and added sugar.

Choose low-fat milks, such as skimmed or partly skimmed milk (≤ 0.7% fat).

Dairy products (excluding creams and milk) were distributed across all Nutri-Score classes, however most (38%) were classified with Nutri-Score D (Additional files 5 and 7). Approximately 86% of cremes were classified with Nutri-Score D, whereas milk and dairy-based beverages were mainly classified with Nutri-Score B (38%) or C (35%) (Additional file 6). Overall, the updated Nutri-Score does not seem to capture the difference in fat content within certain categories of dairy foods, such as cremes and cheeses (Additional file 8).

A total of 38% of milk and dairy-based beverages were classified with Nutri-Score B (Additional file 6). Products classified with Nutri-Score B were generally low-fat, such as skimmed (0.1% fat) or partly skimmed milk (0.5–1.2% fat) and with no or low added sugar content (Additional file 8).

Approximately 30% of yoghurts were classified with Nutri-Score A (Additional file 6). Sugars and saturated fat were the main unfavorable components allocating points within this category (Additional file 9).

Most cheeses and their plant-based alternatives (58%) were classified with Nutri-Score D (Additional file 6). The updated Nutri-Score did not consistently capture large differences in saturated fat content between cheeses as most cheeses with varying saturated fat content were classified with Nutri-Score D, also indicated by the lack of variation in points from saturated fat in the algorithm, i.e. saturated fat contributed with no variation in unfavorable points among cheeses (Additional file 9).

Approximately 86% and 14% of cremes were classified with Nutri-Score D and C respectively (Additional file 6), and no products got a Nutri-Score A or B. In general, full-fat cremes and their low-fat options were classified with D (Additional file 8).

Choose cooking oils, liquid margarine and soft margarine spreads instead of hard margarines and butter.

Replace foods high in saturated fats with foods containing more unsaturated fats.

Fats and oils were mostly categorized with Nutri-Score D (37%) and 27% with Nutri-Score C (Additional file 5). No products in this category got Nutri-Score A.

For subcategories of fats/oils, 100% of butter, butterblends and hard margarine and oils were classified with either Nutri-Score D or E, whereas most (87%) oils and soft/liquid margarine were classified with Nutri-Score B or C (Additional file 6).

Choose foods that are low in salt and limit the use of salt when preparing food and eating.

Choose foods and ready meals with less salt.

Overall, salt was the component contributing with the largest variation in points for many food categories and was the component providing the most unfavorable points (Table 2 and Additional file 9).

Over 80% of crisps were classified with Nutri-Score D or E (Fig. 1 and Additional file 6).

For ready meals, salt was the component providing the most points and the saturated fat was component providing most variation in points (Additional file 9).

Avoid foods and drinks that are high in sugar.

Limit consumption of squash, soda, nectar, sweet cookies, sweet pastries, chocolate, and candy.

Approximately 90% of chocolate/candy were classified with Nutri-Score E (Additional file 6).

Sweet biscuits/pastries were mostly (89%) classified with D or E (Additional file 6).

Respectively, 66% and 27% of sugar-sweetened beverages were classified with Nutri-Score E and D (Additional file 6).

Choose water as a thirst-quencher.

Choose water when thirsty. Limit sugar-sweetened beverages in everyday life.

Other beverages: Choose low-fat/lean milk (≤ 0.7% fat); avoid a high intake of juice, one glass of juice can be counted as one of the daily recommended portions of fruit and vegetables.

Plain water was the only beverage classified with Nutri-Score A.

Nutri-Scores for other beverages are described above.