I would also put an example account or dashboard so people can play with it to understand what it does before going through sign up work.

Another thing is the USDA nutrition info for raw ingredients might be actually a bit out of date, with a lot of the measurements taken long time ago. The actual micronutrient content of raw food can vary greatly depending on what kind of soil it was planted in, how unripe it was before harvesting and many other factors, which isn't shown in this kind of stuff unfortunately. And the quality of soil 30 or 40 years ago is probably radically different than it is now.