Sliced Turkey Sandwich

3 ounces turkey breast + two slices of whole wheat bread + a dollop of light mayo = 315 calories

Add: 1⁄3 cup roasted bell pepper slices
Gain: 35 calories, more than half of your daily requirement (55 milligrams) for vitamin C, along with generous doses of vitamin A and beta-carotene

Add: 2 tablespoons hummus
Gain: 51 calories, another 2 grams of fiber, 2 grams of protein, and nearly a gram of iron

Add: 2 thin slices avocado
Gain: 30 calories, about 3 grams of healthy monounsaturated fat, plus disease-fighting lutein and beta-sitosterol, as well as portions of folate, magnesium, and potassium