This bugs me
When clicking on "Add a Food" we are always taken to the "All" category. Over time I have developed a long list of "Favorites" and will always find the food I want there, many times listed in the first number of entries. But when I select a food and then go to add a second food, I am taken back to "All" again and have to go looking for the entry I want or click on "Favorites" again.
My suggestion: when the user clicks on a category of "Add Foods", that selection becomes the default until the user selects another category. In other words, the last category selected by the user is the default category for that user.