there isn't one "diet" out there that works for absolutely everyone. every person works differently than the next. it takes a lot of trial and error to find out exactly what works best for you. I would recomend by starting by having your diet consist of all whole foods. this means nothing processed, only things that occur naturally. a lot of the time the chemicals that are put in "low fat" foods are far worse for you than the actual fat itself!
to find out what foods best work for you, you could try a rotational diet for a few weeks. this is where you would eat foods from specific groups and rotate the foods while keeping a journal about how you feel each day. this will help pin point if you have any intolerances and what foods you function best on.
if you are really serious about this it may help to set up an appointment with a holistic nutritionist that can help you determine what would work best for your body