Great start for a product. I would imagine everything that's currently in your food database had to be manually chosen due to the availability of training data. It doesn't handle very many branded products, but that could be really valuable in keeping users engaged and using your application daily, so I would suggest adding barcode scanning (currently building an application with the Nutritionix API, its got a great dataset). You could even ask your users to take a picture of their barcode entered food so you can start learning on a much wider variety of products. My two cents.