# Nutrition Intelligence API — USDA FoodData Central for AI Agents

Search 400K+ foods, get detailed nutrient profiles, and compare nutrition side by side. All data from USDA FoodData Central (CC0 public domain). Values per 100g with % daily value.

## API Base URL

https://nutrition.hugen.tokyo

## Endpoints

- GET /nutrition/search?q=chicken+breast — Search foods by name ($0.01)
- GET /nutrition/food?id=171077 — Full nutrient profile for a food ($0.01)
- GET /nutrition/compare?ids=171077,175167 — Compare 2-5 foods side by side ($0.01)

## Parameters

### /nutrition/search
- q (required): Food name to search
- limit (optional): Max results, 1-25 (default: 10)
- source (optional): Filter by data source — sr_legacy, foundation, branded, survey (default: all)

### /nutrition/food
- id (required): USDA FoodData Central ID (fdcId from search results)

### /nutrition/compare
- ids (required): Comma-separated FDC IDs, 2-5 foods (e.g. 171077,175167)

## Response Structure

### Search results include
- fdc_id, description, source, category, serving_size
- macros: calories, protein_g, fat_g, carbs_g, fiber_g, sugar_g

### Food detail includes
- Organized nutrient categories: macronutrients, vitamins, minerals
- Each nutrient: name, amount, unit, daily_value_pct (% of recommended daily intake)

### Compare includes
- Side-by-side comparison table (all values per 100g)
- Macros, vitamins, minerals with % daily value for each food

## Attribution

U.S. Department of Agriculture, Agricultural Research Service. FoodData Central