My kids won't take my advice on anything and certainly don't want to diet with me either so I can relate.

Have your 3 Cambridge servings a day. That is a must. Your added meal of protein and veg (above ground, low starch) should work fine for you. Keeping it to 3 to 4 oz protein and leafy green is ideal. You can use olive oil and lemon or vinegar, salt and pepper as a simple dressing. My husband lost his weight this way.