I am working on a diet app project.
I went through different diet apps available on play store like myfitnesspal. In the case of myfitnesspal, the app has a primary database of food for the Calorie and nutritional information of different kind of foods. It has also got features like Diary. This feature stores all the food entries being made everyday. In the recipes section where user can make custom foods, dishes(combination of foods), meals(combination if dishes).
Now my question is...
should I create three databases differently( for primary food database, for keeping all the daily food entries made by user(DIARY) and for the customized food/dishes/meals user create.
or
create a single database and make different tables for three of those(primary, diary, custom).
Please suggest me which one should i choose for best results and suggest a reference for doing that. Please try to answer in detail and clearly.
Thanks in advance.