FatSecret, a social network focused on nutrition and weight loss that we covered back in 2007, is launching a new API tonight that allows third party sites and services to tap into its database of nutritional data, excercise information, and other health stats. You can access the new FatSecret Platform here.

CEO Rodney Moses says that FatSecret is allowing developers to access the API for free, in the hopes of turning FatSecret into the reliable and accurate resource for nutritional information. He points out the fact that while there are plenty of diet sites on the web that contain nutrition info for various foods, much of the data is disjointed — there’s no established comprehensive source that people turn to first. FatSecret hopes to become the authoritative hub for this kind of information. The site has gathered its data from a number of publicly available resources like the USDA, and also has many user-submitted entries from users on its social network. Moses says that all of the data has been curated to ensure accuracy.

The other component to the new API is a brand utility, which invites food and beverage brand owners to submit their nutrition facts into the system so that they can be retrieved using the FatSecret API.

Moses says that the site itself is still growing steadily, with half a million monthly visitors and around double that number when including users who access the site through other means, like its mobile applications.