{"name":"body_fat","title":"Body-Fat Percentage (U.S. Navy)","category":"fitness","description":"Body-fat % via the U.S. Navy circumference method (height/neck/waist, plus hip for women), the ACE category, and fat/lean mass if a body weight is given.","price_usd":0.001,"input_schema":{"type":"object","properties":{"sex":{"type":"string","description":"'male' or 'female' (default male)"},"height_cm":{"type":"number","description":"Height in centimetres"},"neck_cm":{"type":"number","description":"Neck circumference in centimetres"},"waist_cm":{"type":"number","description":"Waist circumference in centimetres"},"hip_cm":{"type":"number","description":"Hip circumference in cm (required for the female estimate)"},"weight_kg":{"type":"number","description":"Body weight in kg (optional; enables fat/lean mass)"}},"additionalProperties":false,"required":["height_cm","neck_cm","waist_cm"]}}