In moderation, prunes are a good addition to a balanced diet. According to ChooseMyPlate.gov, the average adult should consume 1 1/2 to 2 cups of fruit each day. A 1/2-cup serving of dried fruit is equivalent to 1 cup of fresh fruit. Prunes, which are dried plums, contain more calories per serving than fresh plums -- 209 calories compared to 76 -- but they are a richer source of essential nutrients than their fresh counterparts. Avoid eating prunes between meals, since their high sugar content may contribute to tooth decay.
Low in Fat
Each 1/2-cup serving of pitted prunes contains 0.33 grams of fat, only 0.07 grams of which are saturated fat. This amount would provide a healthy adult on a 2,000-calorie diet with less than 1 percent of her recommended daily limit of saturated fat. Prunes have trace amounts of mono- and polyunsaturated fats and no cholesterol.
High in Carbohydrates
The majority of the caloric content of prunes is supplied by carbohydrates. There are approximately 55.6 grams of total carbohydrates in each 1/2 cup, with 33.2 grams provided by simple sugars such as fructose and glucose. Prunes are also a good source of dietary fiber, with 6.2 grams per 1/2-cup serving, or 18 percent and 22 percent, respectively, of the daily fiber recommendation for men and women.
Excellent Source of Vitamin K
Vitamin K helps strengthen your bones, and it's needed for blood to coagulate properly. Women should have 90 micrograms of vitamin K every day, while men need about 120 micrograms. With nearly 52 micrograms in every 1/2 cup, a serving of prunes fulfills over 50 percent of a woman's recommended daily allowance and around 43 percent of what a man needs every day. Prunes also contain a high amount of vitamin A, and small concentrations of the B vitamins, including vitamin B-6, riboflavin and niacin.
Dense with Potassium
Consuming a 1/2-cup serving of prunes provides you with 637 milligrams of potassium, which is more than you get from a medium-sized banana, a cup of fresh orange juice, or a 1/2 cup of cooked winter squash, spinach or lima beans. Each 1/2 cup of prunes contains 13 percent of the 4,700 milligrams of potassium an adult should have daily. According to the Linus Pauling Institute, a diet featuring a variety of high-potassium foods such as prunes may lower your risk of high blood pressure, osteoporosis and stroke. Prunes also contain iron, copper and manganese.