Add: 1 cup fresh spinach leaves, cooked
Gain: 7 calories, plenty of beta-carotene (1,688 milligrams) and 15 percent of your daily requirement of folate (58 micrograms), and a little potassium, calcium, and iron

Add: 2 tablespoons shredded reduced-fat cheddar cheese
Gain: 45 calories, 4 grams of protein, and 10 percent (100 milligrams) of your daily calcium requirement

Add: 2 tablespoons chopped sun-dried tomatoes in oil
Gain: 30 calories, the cancer-fighting antioxidant lycopene, nearly a gram of fiber, 14 milligrams of vitamin C, and a bit of potassium and magnesium