Nutritional breakdown of tomatoes

One medium tomato (approximately 123 grams) provides 22 calories, 0 grams of fat, 5 grams of carbohydrate (including 1 gram of fiber and 3 grams of sugar) and 1 gram of protein. Tomatoes are a rich source of vitamins A and C and folic acid. Tomatoes contain a wide array of beneficial nutrients and antioxidants, including alpha lipoic acid, lycopene, choline, folic acid, beta carotene and lutein.