At a restaurant, a whole tuna sandwich on wheat may contain up to 600 calories, depending on the recipe and size. However, homemade versions can be far lighter. Using two slices of (45 calories per slice Sara Lee) whole-wheat bread, 3 ounces of water-packed tuna (70 calories) and 1 tablespoon of light mayo (30 calories), and you’ll create a sandwich of about 200 calories. Mixing chopped celery, lettuce or shredded carrots into the tuna won’t add significant calories. Add some brown spicy mustard. We don’t need the chips. A glass of iced tea or diet cranberry juice (Cran-mango!) is a refreshing summertime drink.