When I finally sift through the multiple entries for an item that I am looking for and find one that I trust I don't want to have to repeat that effort.
There are 3 things that I think you should add to the database.
1 - let me mark a food as a Favorite. That means that I use it and I trust the data. I then want to be able to do a search on just my favorites. I know that some people may use the recent foods tab to approximate this feature but what if I want to find something I know I used 3 months ago? It would be so far down on the recent foods list I would never find it.
2 - let me mark a foods as untrusted. I've determined that an entry in the database has bogus data so don't ever show it to me in search results again. You might be able to use this to weed the database. When a high level of users mark an entry this way you might consider deleting it.
3 - let me search my recent foods list. I know I found a good entry for portobello mushrooms a few weeks ago after searching through many incomplete entries. Make it easy for me to find it again.
I think the interface could be improved, On the web version you could show the nutritional info coincident with selecting the item. No need to have to click a button to see it. You have the space.