Covering over 200,000 foods and dishes, MyNetDiary's API provides two services to integrate right into your application: FindFood ( 0.5 cents a query) and GetFoodDetails. The input format is HTTP request parameters or SOAP. Output format is JSON or XML. Food lookup results are sorted by popularity.
Wall Street Journal included MyNetDiary in its comparison of digital calorie counters:
MyNetDiary.com was the quickest to use because it guesses what users are searching for as they start to type. Many of the specific foods we ate (like Japanese Kani salad) were listed thanks to 300,000 contributions from the site's community. Most of the food on our daily log was from contributors. (The other sites let users contribute as well.) We especially liked that our food diary could track things like caffeine and folate. Charts tracking eating patterns were sometimes difficult to understand and didn't have enough detailed information.
In addition to being a successful iPhone app, the exciting part for developers is its API, which has 3 pricing tiers from free to $9 a month.