Every item gets a letter from A to E. Here is exactly how, and where the numbers come from.
The score answers one question: how much nutrition does this give you for the calories it costs? An item packed with protein, fibre, and vitamins scores well. An item that is mostly salt, saturated fat, and sugar scores badly. Size is taken out of it, so a large item cannot win just by being large.
Unusually nutrient-dense for fast food.
More nutrition per calorie than most of the menu.
About typical for fast food.
Little nutrition for the calories.
Its salt, saturated fat and sugar outweigh what it provides.
The letter comes from NRF9.3, a nutrient profiling model published in the peer-reviewed nutrition literature and validated against the US government's Healthy Eating Index. It adds up nine nutrients worth encouraging — protein, fibre, vitamins A, C and E, calcium, iron, magnesium, and potassium — each as a share of its daily value and capped at 100%%, then subtracts three worth limiting: salt, saturated fat, and sugar. Everything is measured per 100 calories.
The cap matters. Without it, one heavily fortified nutrient would outweigh everything else, and a vitamin-sprayed snack would beat real food. With it, an item has to be broadly nourishing rather than spiked.
Nutrition comes from USDA FoodData Central, the US Department of Agriculture's public food composition database. It is public domain and anyone can check it. We use its SR Legacy and FNDDS datasets, which between them carry named restaurant items with full nutrient panels — 168 of them across the chains on this site.
Prices are read from each chain's own ordering system and vary by restaurant, so we say which store and when.
Total sugar, not added sugar. The published model uses added sugar. USDA's older records often do not separate it out, so we use total sugar. For fast food the difference is small — there is little natural sugar in a burger — but it would unfairly mark down anything fruit-based.
A 250-calorie floor on what counts as a meal. Scoring per calorie structurally favours small, light things. Without a floor, “the healthiest thing at McDonald’s” comes back as a yogurt parfait or a salad with the chicken left out. Neither is lunch. The floor is our judgement, not part of the published model, and we would rather say so than hide it.
Sauces, sides, and family packs are labelled and filtered. A 15-calorie sauce packet is not the lowest calorie meal on a menu, and a party pack for twelve is not a healthy choice for one person. Ranking pages only consider items you would order and eat yourself.