I agree with SkinCareDiva. Every person's body chemisty is going to be a bit different as we all look, feel, and are built differently. What works for one of us may not work exactly for the other. General principles are fine but you are going to have to fine tune a diet to work for you that will be what keeps down acne break outs.
IN general, avoid greasy, oily, junk foods. Eat chocolate, and things of this nature in moderation. If you notice breakouts after eating certain foods then try removing them from your diet and see if your skin improves. If so then they are probably triggers for your acne and need to be avoided.
The healthier that you are in general, the better off you will be all over, inside and out, now and in the future.