A 1-ounce serving of pistachios, or about 49 kernels, contains 160 calories, 6 grams of protein, 13 grams of fat, 8 grams of carbs and 3 grams of fiber.
While most of the calories in the pistachio nut come from its fat content, it's primarily in the form of monounsaturated and polyunsaturated fats. The Centers for Disease Control and Prevention says most of the fat in your diet should come from these unsaturated fats. The CDC even suggests snacking on 1 ounce of nuts a day to increase your intake of healthy fats. When these fats are eaten in place of saturated fat, they may help reduce risk of heart disease and improve cholesterol levels, according to the Dietitians Association of Australia.