Carbs in Tomatoes: Are Tomatoes Keto?

Often people are mistaken that the keto diet limits vegetable consumption because the daily carbohydrate amount is limited to 20 grams. However, we have already figured out that vegetables on a keto diet are necessary on a daily basis. What’s more, when following a ketogenic diet, people tend to consume more vegetables than during other diets. And usually, these are green vegetables in large quantities. What about tomatoes? Are tomatoes keto?

The answer is positive. Yes, tomatoes are keto. But at the same time, tomatoes are one of the most controversial vegetables for a ketogenic diet, and there are a number of restrictions on their use. You can eat tomatoes in moderation if you are in stable ketosis. However, you should limit the amount during keto-adaptation. But you can still get the health benefits of tomatoes during your low-carb diet.

So how many carbohydrates are in tomatoes? Will tomatoes disrupt your ketosis? How much can you consume without risking ruining your diet? I will answer all your questions and tell you about the health benefits of tomatoes. Keep reading to find out more!

What are Tomatoes?

The tomato is an annual plant in the nightshade family. Solanaceae contain alkaloids (lectin, saponin, and capsaicin) that are produced by plants to protect against insects. Unfortunately, alkaloids can cause a negative reaction in some people, similar to allergies.

Alkaloids can affect the functions of the neuromuscular and digestive systems in animals and humans and negatively affect the health of the joints. Solanaceous vegetables contain fewer alkaloids than nightshade herbs, and cooking reduces the content of questionable substances by 40-50%.

Some researchers believe that the alkaloids in nightshades contribute to excessive bone calcium loss and deposition in soft tissues. For this reason, it is recommended to exclude nightshades from the diet of patients with osteoarthritis, rheumatoid arthritis, and gout. But there are no accurate and evidence-based studies proving the effect of nightshades on joint diseases.

Solanaceae can cause problems for those struggling with autoimmune diseases. And some people just have a sensitivity to them. A simple way to determine if these foods are bad for you is to cut them out of your diet for a few weeks to three months, then add them one at a time and monitor your well-being.

The vast majority of people have no problem with nightshades. All of these vegetables are low in sugar, and high in fiber, and give a lot of imagination to those who love to come up with keto recipes. Is tomato suitable for the keto diet? Let’s figure it out together!

Are Tomatoes Keto?

The easiest way to determine a low-carb vegetable among forbidden high-carb varieties is to find out if it grows above the ground. And most nightshades, especially tomatoes, fit this rule.

So, 100 grams of tomatoes contain:

  • Protein 1.1 g
  • Fat 0.2 g
  • Carbohydrates 3.8 g
  • Fiber 1.4 g
  • Net carbs 2.4 g
  • Water 92 g.

The calorie content of tomatoes is 18-26 calories per 100 grams depending on the type. Given the composition of this vegetable, we can safely say that tomatoes are keto. However, during adaptation, you should limit the amount to fit within 20 grams of carbs per day, taking into account other foods as well.

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Benefits of Tomatoes on the Keto Diet

Tomatoes have a very rich chemical composition. They contain a very low amount of glucose and many organic acids: oxalic, citric, succinic, malic, and tartaric. Tomatoes contain fiber, pectin, and vitamins: C, B1, B2, B3, B6, E, folic acid, and carotene.

The color of the fruit is provided by carotene, lycopene, and xanthophyll. Nitrogenous substances are represented by protein nitrogen. Tomatoes also contain starch, fiber, and minerals:

  • sodium
  • iron
  • calcium
  • iodine
  • phosphorus
  • magnesium
  • chlorine
  • sulfur
  • silicon.

They also contain carotenoids, which make tomatoes suitable not only for healthy nutrition but also for medical purposes. Moreover, tomatoes of red varieties contain more nutrients than yellow ones. Let’s take a closer look at the health benefits of tomatoes.

Weight Loss and Healthy Metabolism

Tomatoes are useful for those who have various metabolic disorders, especially problems with salt metabolism. Tomatoes should be added to the diet of people who have problems with being overweight.

They are low in calories, which is very important for those who want to lose extra pounds. In addition, they contain chromium, which helps a person to quickly satisfy their hunger and feel full. Chromium also prevents feelings of intense hunger.

Strong Immunity and Healthy Organs

Tomatoes are beneficial for people with digestive tract disorders and heart problems. A large amount of vitamin C and provitamin A helps to strengthen the immune system. Malic and citric acids are essential for normal digestion. These substances regulate the acid-base balance in the human body and also fight aging.

Lycopene, found in tomatoes, is a very beneficial substance that can reduce the risk of malignant tumors. It is a very powerful antioxidant, and it even surpasses vitamins such as C and E. This substance can be used to prevent not only cancer but also cardiovascular diseases. Lycopene also inhibits the development of macular degeneration, which is a common cause of blindness in people over the age of 55.

Potassium in tomatoes has a beneficial effect on the heart’s health and helps relieve swelling. Calcium is essential for strong bones, and magnesium helps our bodies to tolerate cold more easily and regulates healthy sleep. Iron relieves anemia, zinc promotes skin regeneration and hair growth, and phosphorus plays a large part in metabolic processes.

Fresh tomatoes and tomato juice are also very useful for gastritis with low acidity, anemia, memory impairment, and general loss of strength. Tomatoes also act as a mild laxative for constipation.

Excellent Mental Health

Tomatoes are good not only for physical but also for mental health. The thing is that they contain ready-made serotonin, which is considered to be the hormone of happiness, as well as thiamine. Thiamine is an organic compound that is converted into serotonin in the human body.

Due to this composition, tomatoes are able to improve mood. And in times of stress, they act as antidepressants – helping fight depression and other negative consequences of prolonged stress.

Useful Tips

You need to know that the highest concentration of lycopene is contained not in fresh but in boiled or baked tomatoes. It is due to the fact that the number of lycopene increases in the case of processing tomatoes at high temperatures. Moreover, the longer you cook, the more lycopene you can get.

Carbs in Cucumbers: Are Cucumbers Good for Keto?

Therefore, I recommend regularly eating various tomato sauces. I do not recommend buying tomato sauces during a keto diet because most of them contain sugar and various preservatives. You can make tomato keto sauces yourself by following my simple recipes.

Tomatoes will bring real benefits to the body only if you eat at least 20 pieces a week. Tomato salad is best seasoned with a healthy fat such as olive or sesame oil. It will allow your body to absorb lycopene even better.


Most types of tomatoes are low-carb, so we can safely conclude that tomatoes are keto. As long as you control your serving size and count all the carbs in your daily diet, you can safely include these vegetables in your keto meal plan.

Tomatoes contain many beneficial elements and have significant health benefits. So feel free to experiment, make keto salads, soups, and sauces, and enjoy delicious tomatoes during your low-carb diet!


Ana Rinkevich is a writer specializing in health, nutrition, fitness, and weight loss. Over the past 10 years, she has used various methods to deal with obesity, metabolic syndrome, and eating disorders. Proud keto follower for 6 years - lost 100 pounds and fought insulin resistance. Ana shares her experience, tips, and motivation to help people use eating habits for better health and harmony with the body.