HealthKit Nutrition: 39 Dietary Types

HealthKit's Nutrition group is 39 type identifiers, every one a quantity type and every one cumulative. No discrete types. None with the aggregation style left blank. It is the one group in the API where the sum-or-average question has a single answer for every member, and the answer is sum. The list comes from this site's HealthKit identifier dataset, parsed from Apple's developer documentation on 2026-08-28.

Three unit families cover all 39. dietaryEnergyConsumed is the only energy type. dietaryWater is the only volume type. Everything else is mass. Note that the dataset records a unit family rather than a specific unit, so the family tells you the shape of a value and nothing about its magnitude.

The group is also finished. 38 of the 39 shipped with iOS 8.0, and dietaryWater followed in 9.0. Nothing in this group has a later availability than that, so the nutrition side of HealthKit you write against today is the one Apple shipped alongside the original framework.

Five identifiers carry most products. dietaryEnergyConsumed is the calorie total. dietaryProtein, dietaryCarbohydrates and dietaryFatTotal are the macros, and dietaryFatTotal is the only identifier in the group whose documentation runs past the standard one-line abstract, because it sits above three breakdown types: dietaryFatSaturated, dietaryFatMonounsaturated and dietaryFatPolyunsaturated. dietaryWater completes the set, and being volume rather than mass, it will not share a code path with the other four.

Past those five, the group is a long micronutrient list. Minerals get dietaryCalcium, dietaryIron, dietaryPotassium, dietarySodium, dietaryZinc, dietarySelenium, dietaryChromium, dietaryMolybdenum and more. The vitamins are where the naming gets awkward, because Apple documents several of them under two names at once. dietaryThiamin is vitamin B1, dietaryRiboflavin is B2, dietaryNiacin is B3, dietaryPantothenicAcid is B5, dietaryBiotin is B7, dietaryVitaminB6 is pyridoxine, dietaryVitaminB12 is cyanocobalamin, and dietaryFolate is folic acid. Build your mapping table from Apple's identifier names alone and it will silently miss whichever synonym your food source happens to use.

Which brings up the thing that actually decides how much of this group you can fill. Your food database does, not HealthKit. The API defines 39 fields, and if the item your user searched for resolves to four nutrient values, four is what you write. Coverage per item is the number to test when you pick a source, not the headline item count, and the only honest test is running a sample of foods your own users eat through the API. Our notes on nutrition APIs and the USDA FoodData Central and Open Food Facts comparison cover what each source returns per food, and nutrition tracking apps covers the rest of the build.

None of the 39 has a verified Android counterpart in our cross-platform matrix, which tracks ten metrics and does not currently reach into food. Treat the whole group as Apple-only until verified, and if you ship on both platforms, budget the nutrition mapping as real work rather than a rename.

One last consequence of everything being cumulative. The number a user sees is a daily total, and a daily total is only as good as your definition of a day. A snack logged at 00:20 belongs to a different date depending on whether you roll up in the device's timezone, the user's home timezone or UTC, and users notice when yesterday's total changes. Day boundaries and timezones covers the rollup that survives travel.