Well first off, you do need some carbs. They give your body energy, and if you have no carbs your body will cannibalize the protein in your muscles for energy synthesis. Have a bowl of kellogs of cheerios in the morning, but I wouldn't say you need much more good carbs than that.
Chicken, fish, stay away from fatty foods and sugar. Don't drink ANY soda, just stick to water or fruit juice (but mostly water, fruit juice nowadays is almost as bad as soda) veggies, maybe get a vitamin supplement or something. Otherwise, just run 3-4 days a week and work out 3-4 days a week and you'll be golden. You may or may not get to where you want in 3 months, but if you make it to 3 months, you'll probably feel your life style changing and you'll just keep working out, and eventually you'll hit where you want to be.
Good luck!
