Here are the nutrients in a small (100-gram) raw tomato (1Trusted Source):
- Calories: 18
- Water: 95%
- Protein: 0.9 grams
- Carbs: 3.9 grams
- Sugar: 2.6 grams
- Fiber: 1.2 grams
- Fat: 0.2 grams
Carbs comprise 4% of raw tomatoes, which amounts to fewer than 5 grams of carbs for a medium specimen (123 grams).
Simple sugars, such as glucose and fructose, make up almost 70% of the carb content.
Tomatoes are a good source of fiber, providing about 1.5 grams per average-sized tomato.
Most of the fibers (87%) in tomatoes are insoluble, in the form of hemicellulose, cellulose, and lignin (2).