I (try at this point) do a 'no flour/no sugar' diet. When I was totally serious about this I lost about 65 lbs in just over a year. No refined flour; no refined sugar. Natural starches/sugars are fine. So...potatoes; rice; other natural carbs are fine. Fruit also fine. It is a challenge initially reading lots of labels but it's very doable. I also never worried about portion size. It worked for me.