Are Tomatoes Keto-Friendly?

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Written by Bridget Nalwoga, Certified Nutritionist and medically reviewed by Abby Courtenay

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Starting out on keto can be challenging, especially when it comes to determining what foods you can or cannot have on the diet

Foods like bread, pasta, and potatoes are easy to eliminate as they are obviously carb-based. However, some foods like tomatoes may not be as easy to figure out. 

With the tomato being the one of the most popular vegetables in the world, it is no surprise that one would want to have it on keto. However, does it qualify? Read on to find out if it is keto-approved, how much you can have, and whether tomato products make the cut.


What is a tomato?

A tomato is an edible red berry-like fruit. It has its origins in South America, but starting in the 16th century, it was spread across the world and has since become popular among most cultures worldwide. 

There is an old saying that goes, ‘knowledge is knowing that a tomato is a fruit and wisdom is knowing not to put it in a fruit salad.’ 

The tomato has been used as a vegetable for hundreds of years, but is in fact botanically a fruit. If you are surprised by the fact that the tomato is a fruit, just remember that the rule of thumb is anything with a seed or seeds is a fruit. Yes, eggplant as well! 

You might already know that fruits are not the most keto-friendly food category, but there are fruits low enough in sugar to suit the keto lifestyle, and the tomato is one of them. 

Other fruits that are suitable for a low-carb diet include zucchini, eggplant, and avocado.


Tomato nutrition facts

Tomatoes have a nutrition profile typical of vegetables: 

  • high in vitamins, and minerals.
  • low in simple carbohydrates (sugars), protein, and fat.

Serving size: 100 g fresh. Equal to about 1.5 small-sized fruit (Roma variety).

  • Calories: 22 KCal
  • Fat: 0.42 g
  • Total carbohydrates: 3.8 g
  • Dietary fiber: 1 g
  • Net carbs (total-fiber): 2.8 g
  • Protein: 0.7 g

Serving size: 1/2 cup grape tomatoes

  • Calories: 20 KCal
  • Fat: 0.5 g
  • Total carbohydrates: 4.2 g
  • Dietary fiber: 1.6 g
  • Net carbs (total-fiber): 2.6 g
  • Protein: 0.7 g
  • Vitamin C: 20.65 mg, 34% DV*

*% DV = Percentage of the total daily recommendation

From the information above, you can see that eating 1.5 small Roma tomato and ½ cup grape tomatoes would give you only 5.4 g of net carbs.

Are tomatoes high in sugar?

No, from the carb count we can see that the amount of sugar in a tomato is also low. It may surprise you, but onions actually have more sugar than tomatoes! 

Remember that the nutrition profile above is only for the fresh raw fruit. Tomato dishes and products have different nutrition profiles that may not be keto-friendly.




Are tomatoes ok on keto?

Yes, tomatoes are very safe to eat on a ketogenic diet. 
One whole fruit contains less than 7% of your daily net carbs (if your limit is 50 g per day). You would need to eat more than 15 fruits to reach or exceed your limit. That is very unlikely.

The low net carb content is not the only reason the tomato is wonderful for keto. 

The fruit has a rich micronutrient profile, particularly beta carotene, and vitamin C, and the mineral potassium. The vegetable, or fruit if you prefer, is also rich in phytonutrient lycopene. 

Beta carotene/ v A is important for maintaining eye health and strengthening immunity, while C is great for skin health, heart health, and immunity too. 

The antioxidant lycopene has disease-protective properties particularly for prostate cancer in men. 

While a tomato’s fiber content cannot match up to that of other vegetables like kale, it is still good to have. Any amount of dietary fiber is appreciated on keto because of the absence of whole grains on the diet.


How many tomatoes can you have on a ketogenic diet?

The amount of tomatoes you can eat in a day depends on your individual carb limits. 3 small Roma tomatoes / 1 cup grape tomatoes contains about 5-6 g carbs, so factor this in when you are choosing how much to have. Including a variety of foods in your diet is important for your health, so try not to use all your carbs on one type of food.


What type of tomatoes can you eat on keto?

We have established that the tomato is keto-approved, but one might wonder, “does this apply to all varieties?”

There are over 10,000 tomato types, but the most popular are Roma (plum), beefsteak, cherry, and grape. 

The good news is all the varieties have a similar nutrient composition, so you do not have to worry about what kind you are eating. 

Larger varieties like Roma and beefsteak are rarely eaten in very large amounts, but some people might enjoy snacking on the smaller kinds.

Are tomato products safe to eat on a ketogenic diet?

While any kind of tomato in its raw form is suitable for keto, tomato products do not get the same pass. Some of the tomato products you should watch out for on keto include:

  • Tomato paste: Tomato paste on its own has a moderately high amount of carbs, but it is very unlikely that you would eat it alone. You can afford to use a few tablespoons in your dishes as every serving will have only a fraction of the total carbs.   
  • Tomato sauce: Be wary of store-bought brands and check the nutrition label for added ingredients. You can make your own keto-approved version from scratch.
  • Ketchup: Ketchup has so much sugar added to it that it could be candy. 2 tablespoons of Heinz ketchup contain 8 g of sugar. Low-sugar ketchup is available on the market, but always read the nutrition label to make sure the carb content supports your goals. 
  • Salsa: If you are a salsa lover, the safest option is to make yours at home. Salsa is naturally low in net carbs, but some brands and restaurants may add sugar to their recipes.
  • Tomato juice: Any type of juice is a concentrated version of the fruit or vegetable it comes from. With tomato juice, 1 cup will cost you about 10 g carbs.
  • Canned tomatoes: These tend to have a nutrition composition similar to that of fresh tomatoes. Unless sugar is added, the carbs in canned tomatoes are comparable to those that are fresh. 
  • Sun-dried tomatoes: Due to low moisture content, the net carb content per gram of a sun-dried tomato is greater than that of a raw one. You should either steer clear of them or carefully portion them out to fit your daily carb goals.




Keto-friendly tomato substitutes

Tomatoes are definitely keto-friendly and do not need to be substituted. However, it helps to have a variety of similar foods you can enjoy on keto. Other fruits you can enjoy on keto include:

  • Avocado
  • Strawberries
  • Watermelon
  • Cantaloupe
  • Raspberries

Sweet fruits like raspberries and strawberries are excellent for snacks between meals. Avocado can be used in place of tomatoes as a side dish. You can also use avocado to make sauces and dips like guacamole.


Questions about tomatoes on a low-carb diet

Still have doubts or questions? No worries. Below we answer some of the confusing questions you might have about eating tomatoes on a ketogenic diet.

For starters, you can eat tomatoes raw as a snack. Cherry and grape tomato varieties make great afternoon snacks. The best part is that when you eat raw tomatoes on their own, you do not have to worry about carbs from other foods and ingredients. 

If plain raw tomatoes are not your ideal snack, you can opt for chopped-up salads or tomato salsa. 

Pro tip: Top your salad or salsa with some goat cheese or your favorite type of cheese to make it even more ketogenic. The cheese will improve the fat and protein content, make the salad more filling, and elevate the taste of your dish. 

Try this low-carb keto-safe recipe for tomatoes in a Caprese salad as a snack or side dish.


  • Ripe tomatoes, thinly sliced (1/4 inch)
  • 12 oz. mozzarella cheese, sliced
  • 3-4 sprigs fresh basil leaves 
  • 2-3 tsp. extra virgin olive oil
  • 1 tbsp. Worcestershire sauce
  • Kosher salt, to taste
  • Cracked black pepper, to taste


  1. Arrange the tomato slices, mozzarella slices, and fresh basil leaves, alternating each ingredient. Feel free to just mix it up.
  2. Drizzle with olive oil and Worcestershire sauce. 
  3. Sprinkle kosher salt and black pepper to taste.
  4. Enjoy!

Yes, you can eat carrots and tomatoes on a low-carb diet. 

Carrots are non-starchy vegetables, which are generally acceptable on low-carb diets. Tomatoes, while fruits, are very low in net carbs making them suitable for low-carb diets. You can pair baby carrots and cherry tomatoes with a keto-safe dip like hummus to enjoy as a snack.

Yes, you can eat Ro-Tel on keto, but you have to watch the portion sizes.

1 cup of original diced Ro-Tel contains about 6 g of net carbs, which is ok if you have a high carb limit, for example, 50 g. If you have a lower limit, you should opt for a smaller serving size. 

Other varieties of Ro-Tel may have more carbs, for example, the Chipotle flavor has 10 g of net carbs per cup.

Both grape and cherry tomatoes are keto-safe foods. There is barely a difference between the nutrition compositions of cherry and grape varieties.

Yes, tomato and cheese is the ideal combination for a keto snack. Cheese provides fats and some protein while tomato provides vitamins, minerals, and fiber. 

You should however watch your portion sizes as the carbs in some cheeses, like ricotta, can add up fast.

Any tomato variety is okay to plant for a ketogenic diet. Some of the popular varieties for planting include beefsteak, grape, cherry, and plum.


More vegetables allowed on the ketogenic diet