Pineapple juice delivers sweet taste along with a healthy dose of vitamin C and nutrients. Because the juice is concentrated and often sweetened, calorie counts are considerably higher than a single serving of raw pineapple.
The United States Department of Agriculture defines a single serving of fresh pineapple juice as one cup. There are 25 grams of sugar, and 32 grams of carbohydrate in each cup.
One cup of fresh pineapple juice contains 130 calories. By way of comparison, a cup of pineapple chunks contains 82 calories. Pineapple juice also provides 325 milligrams of potassium per serving, and 182 percent of the recommended daily value for vitamin C.
Where the calories come from in a food may be more important than the total number of calories, according to Harvard Nutritionist Walter Willett in his book, "Eat, Drink and Be Healthy." In one serving of pineapple, 126 of the calories come from energy-providing carbohydrates. Of the remaining calories, 3.4 come from protein and only 0.6 from fats.