Depending on where you are coming from, but making home made food, listening to when you are full, varied foods including vegtable/fruit, and reduce sugar goes a long way.
Processed meat and beef can also be good to reduce, appears in a lot of studies in the wrong column. Incorporating som lentils, peas, and/or beans are good. Olive oil also. I am a fan of the milder taste of canola oil for cooking.