Categorized list?

I'm trying to create a system to store virtual "objects". Each object will be in a category, and the categories may be in other categories. The categorie list might look something like: Food Candy Healthy Food

       Vegeterian food
       Organic food

Gross food I'm thinking of a datbase structure for the categorys something like: id (int, auto_inc, primary) name (text) insideof(int, id of other catrgory which this one is inside of) The problem is, I need to generate an indented list such as I showed before. I know how to do this with a lot of colors (selecting what each category contains, etc.), but is there a more effieient way? I use mysql. Thanks for any ideas.