How we score foods

Every food on NutriVerdict carries a Nutrient Density Score from 1 to 100. This page explains precisely how it is calculated, so you can judge whether it measures what you care about.

What the score measures

The Nutrient Density Score measures how many beneficial nutrients a food provides for the calories it costs, relative to the other foods in our catalog. A high score means a lot of nutrition per calorie; a low score means mostly calories with little else. It is built entirely from the food's real per-100-gram values in USDA FoodData Central.

The formula: a published nutrient-density index

We do not invent our own metric. The score is based on the peer-reviewed Nutrient Rich Foods (NRF9.3) index (Drewnowski and colleagues), a widely used measure of nutrient density. For each food we compute, per 100 kilocalories:

• A positive component: the sum of the percentage of the FDA Daily Value supplied by nine nutrients to encourage - protein, fiber, vitamin A, vitamin C, calcium, iron, potassium, magnesium and vitamin E. Each nutrient is capped at 100 percent so a single one cannot dominate.
• A negative component: the sum of the percentage of the maximum reference value for three nutrients to limit - saturated fat, sodium and sugars.

The raw index is the positive component minus the negative component. Because it is measured per 100 kilocalories, it rewards foods that are nutrient-rich for their calorie cost rather than simply calorie-dense.

From raw index to a 1-100 score

The raw NRF index is heavily skewed - leafy greens sit far above everything else, while pure fats and sugars fall below zero - so a plain rescale would bunch most foods together. Instead we express the score as a percentile rank across our whole scored catalog: the median food scores 50, a food in the top ten percent scores about 90, and the least dense foods score near 1. The score is therefore an honest relative measure ("more nutrient-dense than X percent of the foods we cover"), not an absolute health grade. The same formula runs on every food, so the ranking that falls out of it is reproducible and carries no editorial thumb on the scale.

What it is NOT, and its honest limits

• It is not a verdict on whether a food is "healthy" for you. Health depends on your whole diet, your needs and how much you eat, none of which a single number can capture.
• Because it is measured per calorie, it favors low-calorie, nutrient-rich foods such as leafy greens and rewards them over calorie-dense whole foods like nuts, oily fish or eggs, which are nutritious in other ways. Read the score alongside the full nutrition panel, not on its own.
• FoodData Central's SR Legacy set reports total sugars, not added sugars. We use total sugars in the "limit" component, which slightly penalizes naturally sweet whole foods such as fruit. We flag this rather than hide it.
• Foods with almost no calories (for example plain water or black coffee) cannot be scored per calorie in a meaningful way, so they are shown without a score.

Goal tags and rankings

Our goal tags (high protein, high fiber, low calorie, low sodium, low sugar, and "rich in" tags for potassium, iron, calcium, vitamin C and vitamin A) are awarded from the food's real numbers against fixed thresholds, aligned with FDA nutrient-content-claim conventions where possible (for example, "low sodium" at 140 milligrams or less, and a "rich in" tag at roughly 20 percent of the Daily Value). A food earns a tag only if its actual values clear the threshold. Our "best for" rankings simply order the foods that earn a tag by their Nutrient Density Score.

Sources and freshness

All values come from USDA FoodData Central, SR Legacy release (public domain). Every food page links to its official FoodData Central record, which is always the authority. Found a figure that looks wrong? Let us know.