Methodology: How Every Food Gets Rated

Every verdict on this site is produced by one fixed rule set applied to one public dataset. The dataset: USDA FoodData Central (SR Legacy), 6,689 foods with per-serving sodium and potassium values computed from standard serving sizes. The rule set: the two-number thresholds below, the potassium pairing rule, and five processing vetoes. Nothing on the site is rated by opinion, and no food gets a different rule than its neighbor.

Thresholds. GREEN — blood-pressure-friendly: under 140 mg sodium per serving (the FDA "low sodium" line), or an amber sodium level lifted by the potassium pairing rule below. AMBER — moderation: 140–340 mg sodium per serving; portion and frequency discipline apply. RED — limit: above 340 mg sodium per serving, or any veto trigger. These are the only three bands, and the red line is a hard one: a food above 340 mg of sodium per serving is red and stays red.

Veto triggers. Five processing categories carry sodium structurally and override the raw number. Brine-cured and salt-pickled products qualify once they sit at or above the low-sodium line, so the pickle paradox holds for a 283 mg spear, while a reduced-sodium pickle under 140 mg is rated on its number like anything else. Cured and processed meats are vetoed as a category. So are ultra-processed carriers — foods whose sodium arrives in the formulation rather than the ingredient list, which is how a snack cracker can read low per unit and still fail. Very-high-sodium items at or above 800 mg per serving are vetoed outright (see the canned soup case file), and hard liquor joins them. These five are the only category-level overrides in the system.

The potassium pairing rule. Potassium lifts an amber food (140–340 mg sodium per serving) to green only when the same serving carries at least 350 mg of potassium. Below that level the food stays amber. The rule runs in one direction only: it can improve an amber verdict, and it can never rescue a red one — a red food with a strong potassium column is still red. This asymmetry follows the clinical logic: potassium is a supporting lever, sodium is the ceiling.

What does not move a verdict. Saturated fat, total sugar, fiber and calorie columns appear as context where the database carries them, but a verdict is produced only by sodium, potassium and the five veto triggers. We state this explicitly because it is a deliberate scope decision: this site scores the two numbers that drive blood pressure, and a food is not downgraded for a nutrient outside that scope. Hard liquor is the single exception, and it enters through a veto trigger rather than a nutrient threshold.

Versioning. The rule library is versioned (current: v1.36). Rule changes are versioned in place, never silently; past versions are archived. v1.35 restricted the verdict to the two-number scope above and stated the potassium pairing threshold exactly at 350 mg per serving in place of earlier approximate wording. v1.36 closed two gaps that wording left open: the veto list is five categories rather than four, because ultra-processed carriers were always vetoed in the rule library and the published list now says so out loud; and the salt-pickled veto was stated too broadly — it now applies at or above 140 mg per serving, so a genuinely low-sodium pickle is rated on its number, the same way the dill-pickle page already showed it. The same pass re-rated three rows of the seaweed verdict that had been coloured on a per-100 g basis while printing per-serving figures. Every change, and its effect on published pages, is logged on the corrections page. Ratings shown on the site always reflect the current library.