Calories and Nutritions in Tomato

According to the USDA FoodData Central, a 100g serving of tomatoes contains 18 calories.

Based on the data from USDA's FoodData Central, 1 kilogram of tomatoes contains 180 calories.

The calorie content of 1 tomato varies depending on the size and variety of the tomato. A plum tomato, which has a weight of 62g has 11 calories. A cherry tomato which typically weighs 17g contains 3 calories. A small tomato with a weight of 91g contains 16 calories, while a large tomato weighing 182g has 33 calories.

Tomatoes are low in calories and high in nutrients. The health benefits of tomato are listed below:

• Prevents heart disease: Tomato contains lycopene and beta carotene, which have been found in studies to lower the risk of heart attack and stroke. One particular study on tomatoes found that consuming it regularly reduces inflammation, prevents oxidative stress, protects the blood vessels inner layer and reduces risk of clotting.
• Boosts skin health: The lycopene in tomatoes protects against sun damage and sunburn.
• Helps prevent cancer: Observational studies on tomato and tomato-based products found that regular consumption leads to lower risk of lung cancer, stomach cancer and prostate cancer.
• Strengthens the immune system: Lycopene is an antioxidant, which fights free radicals that affect the immune system. 
• Maintains eye health: Plant compounds like lutein and zeaxanthin which are abundant in tomatoes protect your eyes from blue light and prevent eye strain. Some research also shows that eating tomatoes regularly may also prevent macular degeneration. 

Eating tomatoes come with some disadvantages as listed below:

• May cause heartburn and acid reflux: The acid in tomatoes irritates the esophageal lining, which may further increase the acid level in the stomach.
• May lead to kidney problems: Tomatoes contain potassium which offers many health benefits. However, consuming too much could impair kidney function, especially for individuals with existing kidney problems. Moreover, tomatoes contain oxalate which can lead to kidney stones.
• May trigger allergic reactions: Tomatoes contain natural allergy compounds which may trigger a reaction in some people, producing symptoms like skin rashes and even anaphylactic shock in worst cases. 

Yes, tomatoes are good for you because they're abundant in vitamins, minerals, and plant compounds that provide plenty of health benefits. Tomatoes boost the immune system, protect the eyes and skin, prevent heart disease, lowers the risk of cancer, and reduces inflammation in the body.

No, tomatoes are generally not considered bad, however, consuming it may pose a risk for some people. Individuals with existing kidney problems are advised against consuming a lot of tomatoes and tomato-based products due to their potassium content. People with tomato sensitivity may experience itching, swelling, shortness of breath, diarrhea, and nausea. 

There is no recommended number of tomatoes to eat per day, but it's always best to take anything in moderation. One medium-sized tomato can provide about 19% of the Vitamin C requirement and 11% of Potassium requirement based on recommendations from the National Institutes of Health.

Tomatoes are generally safe to eat unless a person has acid reflux, Chronic Kidney Disease, or an allergy to tomatoes. There is also no upper limit to the amount of tomatoes one can safely consume. However, eating too many tomatoes can cause a condition called lycopenodermia, a condition that makes the skin appear washed out and may also lead to gastrointestinal issues.

Calorie content in tomatoes changes based on size, water content, and variety. Smaller tomatoes like grape and cherry contain fewer calories, with one grape tomato having about 1 calorie and one cherry tomato containing 3 calories. Medium-sized varieties such as Roma and heirloom have slightly more calories. One Roma tomato contains 11 calories and one heirloom tomato has approximately 22 calories. Larger tomatoes like beefsteak have the highest calorie content at 33 calories. 

Tomatoes first grew in the wild in the Andes of South America where indigenous people began cultivating them. They carried the plant north through Central America and into Mexico where the native people called it "tomatl." When Spanish explorers arrived in the early 1500s they discovered tomatoes being grown as a food crop and took seeds back to Spain. The plant spread to Italy by the mid-1500s and later across Europe, though it was mostly used as decoration rather than food.

Many Europeans believed tomatoes were poisonous because they belonged to the nightshade family. Some called them "poison apples" after wealthy people became ill or died from eating them. The real cause was lead poisoning from pewter plates reacting with the acid in tomatoes. Despite the early fears, tomatoes gained popularity and by the 1700s they returned to the Americas with European settlers. Northern colonies first grew them as ornamental plants while southern regions cultivated them for food. Their popularity kept growing and by the early 1900s tomatoes became a staple in the United States.