With a crisp texture and a mildly sweet, grassy flavor, string beans, also called snap beans, make a healthful addition to your diet. According to the USDA guidelines, string beans fall into the "other vegetables" category, as opposed to beans and peas, starchy vegetables or dark green, red or orange veggies. Each cup of string beans provides one-quarter of the weekly "other vegetable" intake for women and one-fifth for men. String beans boast an impressive nutritional profile, and they offer nutrients ranging from dietary fiber to essential minerals.

String beans make a great addition to a calorie-controlled diet, because each cup contains just 31 calories, or 2 percent of the daily calorie intake in a 2,000-calorie diet. Each serving of string beans offers 7 grams of carbohydrates, including 2.7 grams of dietary fiber, as well as 2 grams of protein and less than half a gram of fat. The carbohydrates in beans provide energy while their fiber content promotes digestive health, and the beans' protein content maintains the health of your hair, muscles and skin.

Add string beans to your diet as a source of vitamins, particularly vitamins A and C. Your body uses vitamin A to support your immune system, as well as to maintain healthy skin and eyes, while vitamin C maintains the strength of your blood vessels, bones and teeth. A cup of string beans offers 12 milligrams of vitamin C and 690 international units of vitamin A. This provides 16 percent of the vitamin C and 30 percent of the vitamin A requirements for women, as well as 14 and 23 percent of the recommended daily vitamin C and A intakes for men, respectively, according to the Institute of Medicine.

String beans also provide a considerable amount of iron, as well as small amounts of other minerals. Iron plays a central role in your body's ability to use oxygen -- it allows your muscles to store oxygen for future use, and helps your red blood cells circulate oxygen in your bloodstream. Each serving of string beans contains 1 milligram of iron -- 6 and 13 percent of the Institute of Medicine-recommended daily intakes for women and men, respectively. String beans also serve as modest sources of magnesium, calcium and phosphorus.

String beans are a convenient snack served raw -- eat them on their own, or pair them with hummus, guacamole or fresh salsa. Use string beans as a healthful side dish -- they work well lightly coated in toasted sesame oil and then roasted, or sauteed with minced garlic and olive oil. Alternatively, steam string beans and season with lemon juice and black pepper. Eat the steamed beans as a side dish, and use any leftovers as a topping for leafy green salad or as a filling for wraps.