Princeton's WordNet(4.60 / 5 votes)Rate this definition: 1  operation(noun) the state of being in effect or being operative. 2  operation(noun) a business especially one run on a large scale. 3  operation(noun) a planned activity involving many people performing various actions.
Tomatoes are a nutrient-dense food, meaning they are jam-packed with nutrients, but don't have a lot of calories. Lipids, carbs and protein are the three types of macronutrients your body breaks down for energy. The primary macronutrient in tomatoes is carbohydrates, although they do have trace amounts of fat and protein.
Between 10 and 35 percent of your caloric intake needs to come from protein. Similar to carbs, protein also offers 4 calories per gram. A 1,600-calorie diet requires 40 to 140 grams of protein. Since tomatoes contain mainly carbs, your 1/2-cup portion contains a minimal 1 gram of protein, or 4 calories from protein.