I’m working on one but haven’t had enough time lately. Fundamentally, I believe it’s a convex optimization problem, with each ingredient represented as a vector with values for each nutrient. I was making some progress with the macronutrient side of the equation, but micronutrients get really frustrating because there is so little standardization regarding quantity measuring (International Units vary significantly from vitamin to vitamin).
Another frustrating came from data entry, good luck getting accurate data for each ingredient in any reliable form. The FDA is terrible about this. As an example, compare the nutrition information of Creatine Powder with that of a T-Bone Steak. Surprised to see that creatine is completely absent from the latter? I was. Most nutrition labels are stored in image form too! So you have to manually convert the data to CSV or JSON. I hope to use mechanical turk for this soon, but haven’t gotten around to it.
Does anyone know any good nutritional supplement data APIs? Wolfram is good for data about general things like “one apple” but bad for a specific brand of protein powder, etc.
If you would like to keep in touch as this project develops, please keep this thread going or email me at email@example.com