1. Vegetables. Packed with powerhouse nutrients, vegetables are naturally low in calories, and they're full of fiber, so they're plenty filling. Loading your plate with vegetables will automatically mean you're eating fewer simple carbs (which raise blood sugar) and saturated fats (which increase insulin resistance). Aim to get four or five servings a day. (A serving is 1/2 cup canned or cooked vegetables or 1 cup raw vegetables.) Go easier on starchy vegetables -- including potatoes, corn, and peas -- which are higher in calories than other vegetables.