I would suggest incorporating protein in with each meal or snack. If you are going to have oatmeal for breakfast, have some eggs or chicken or nuts or something else to make your breakfast stay with you longer.

Also, I know a lot of people will disagree with me on this one. But I think soy is bad food, unless it is properly prepared or fermented. It definently should only be a sometimes food if consumed. Because soy has substances that can act like hormones for women, I think women with PCOS especially should avoid it like the plague. PCOSers already have major hormonal issues anyway.

For your fast metabolism, adding natural fats and proteins should help you out. One of the probs with foods like museli is that it is mostly carb so your body burns through it very quickly. I know you are avoiding dairy, but maybe you can incorporate eggs, fish, nuts (almonds, macadamias, walnuts, pecans), fowl, and red meat.