Add: 8 small olives, chopped
Gain: 30 calories, 4 grams of healthful monounsaturated fat, a gram of iron, nearly a gram of fiber, and some calcium (23 milligrams)

Add: 1 1⁄2 ounces grilled chicken breast
Gain: 47 calories, 10 grams of lean protein, plus more than 10 percent (nearly 4 milligrams) of your daily niacin requirements and some zinc and iron

Add: 1⁄4 cup green bell pepper strips
Gain: 5 calories, 25 percent (25 milligrams) of the daily requirement for vitamin C, along with small amounts of vitamin A and potassium