Substituting basmatti rice for potates and using canned beef or chicken broth for gravy are two hints I gave my DB. He was a potato and gravy eater...
Having a bit of broiled, grilled or boiled meat with each meal helps to fill you up when you are increasing the veggies. Spread the meat out over all 4-5 meals... I cook up meat and freeze it in broth or gravy. I can pull out small portions then for each meal.
Substitute olive oil whenever possible, it is heart healthy. It does not work well with deep frying, but sauteing herbs, garlic, onions in it and then cooking your meat or veggies give them a wonderful flavor.