Can You Eat Tomato Soup on a Keto Diet?

November 28, 2025 •

3 min read

According to nutrition data, a typical serving of canned tomato soup can contain over 20 grams of net carbs, potentially derailing ketosis. This raises the question: can you eat tomato soup on a keto diet, or should you avoid it entirely?

Quick Summary

This article explores the carb content of tomato soups, revealing why store-bought versions are often problematic for keto dieters and how easy homemade alternatives can satisfy cravings without the carb load. It covers essential ingredients, recipe adjustments, and tips for staying in ketosis.

Key Points

Canned is generally a 'no': Most commercial tomato soups are high in added sugars and carbs, which can quickly disrupt ketosis.
Homemade is the way to go: Making your own tomato soup from scratch allows for full control over ingredients and carbohydrate count.
Swap for high-fat ingredients: Use heavy cream, cream cheese, or coconut milk instead of low-fat options to increase fat and creaminess.
Avoid starchy thickeners: Skip flour or cornstarch and use an immersion blender or xanthan gum for a smooth, thick consistency.
Read labels carefully: If buying any canned tomato products, always check for hidden sugars and other high-carb ingredients.
Boost flavor with keto additions: Enhance taste with fresh herbs, bone broth, and high-fat toppings like cheese or bacon.
Fresh tomatoes are low in carbs: Although a fruit, fresh tomatoes are low in net carbs and perfectly fine in moderation on keto.

Store-Bought vs. Homemade: The Keto Challenge

While fresh, raw tomatoes are surprisingly low in net carbs and generally considered keto-friendly, the picture changes significantly with tomato soup. The key difference lies in how the soup is prepared. Store-bought, canned, and condensed tomato soups are typically loaded with added sugars and thickened with starches or flour, dramatically increasing their carbohydrate count. A single serving of condensed tomato soup can easily consume a significant portion of your daily carbohydrate allowance, making it a poor choice for maintaining ketosis.

The Hidden Carbs in Commercial Soups

Traditional canning processes and recipes often rely on high-carb ingredients. For example, Campbell's Condensed Tomato Soup contains around 20g of net carbs per serving, primarily from added sugar and high-fructose corn syrup used to balance the tomato's acidity. Even 'healthy' or 'organic' store-bought versions can contain hidden sugars, so reading nutrition labels is crucial.

The Benefits of Homemade Keto Tomato Soup

The best way to enjoy tomato soup on a ketogenic diet is to make it yourself. This allows for complete control over ingredients, ensuring you use low-carb alternatives and avoid added sugars. A homemade keto tomato soup can be rich, creamy, and flavorful while keeping net carbs well within your daily limit. By swapping high-carb thickeners and sugars for keto-friendly options like heavy cream or cream cheese, you can create a satisfying meal.

Creating Your Own Keto-Friendly Tomato Soup

Making your own low-carb tomato soup is surprisingly simple. The foundation is a base of low-carb, high-fat ingredients, building flavor without excess carbohydrates. Here is a basic recipe to get you started:

Ingredients: 2 tbsp olive oil or butter, 1 small chopped onion, 2 cloves minced garlic, 28-ounce can crushed or diced tomatoes (no added sugar), 2 cups chicken or vegetable broth, 1 cup heavy cream or cream cheese, fresh basil, salt, and pepper to taste.
Instructions: Sauté onion and garlic in butter/oil until soft. Add canned tomatoes, broth, and seasonings. Simmer for 15-20 minutes. Use an immersion blender to blend until smooth. Stir in heavy cream or cream cheese and heat gently. Garnish with fresh basil. Note: Some recipes use a small amount of xanthan gum for thickening, but it's optional.

Ingredient Comparisons for Keto Tomato Soup


Ingredient Category	Keto-Friendly Option	Avoid This Option
Tomatoes	Canned crushed/diced (no added sugar), fresh roma or cherry tomatoes	Canned condensed soup, pre-made sauce with sugar
Creaminess	Heavy cream, cream cheese, coconut cream, almond milk	Cow's milk, low-fat milk, traditional dairy
Thickeners	Xanthan gum, immersion blender, cooking down	Flour, cornstarch
Flavor	Fresh basil, garlic, onion, bone broth, Italian seasoning	High-sugar ketchup, sugary tomato pastes
Toppings	Shredded parmesan, crushed pork rinds, grilled halloumi	High-carb croutons, crackers, regular bread

Advanced Flavor Techniques and Pairings

For those looking to enhance their homemade keto tomato soup, consider these techniques and pairings:

Roast your tomatoes: Roasting fresh tomatoes before blending caramelizes their natural sugars, adding a deeper, richer flavor profile to the soup. Add high-fat elements: Incorporate bacon, pancetta, or olive oil to boost fat content and satiety. Pair with keto-friendly sides: Enjoy your soup with a keto grilled cheese made with almond flour bread or cheese crisps for a complete meal.

For more detailed keto recipes and cooking techniques, a resource like Healthline can be invaluable: https://www.healthline.com/nutrition/foods/tomatoes

Conclusion: Mindful Choices for Keto Success

In summary, while store-bought tomato soup is generally off-limits for a ketogenic diet due to its high sugar and starch content, homemade keto tomato soup is not only possible but can be a delicious and comforting low-carb meal. By being mindful of your ingredients and utilizing high-fat, low-carb alternatives, you can enjoy a classic comfort food while staying in ketosis. The key is in preparation and careful ingredient selection to ensure your soup aligns with your dietary goals. Starting with fresh or unsweetened canned tomatoes and enriching the base with heavy cream or cheese are the best ways to create a satisfying and keto-compliant dish.

Optional Outbound Link to an authoritative site

For additional guidance on which foods fit into a keto diet, resources like the USDA's food database can provide detailed nutritional information: https://fdc.nal.usda.gov/

Frequently Asked Questions

Canned tomato soup often contains a significant amount of added sugar and high-fructose corn syrup to balance the tomatoes' acidity and to thicken the consistency with starch, making it too high in carbohydrates for a ketogenic diet.

Yes, using canned crushed or diced tomatoes with no added sugar is a great base for a homemade keto tomato soup. Always check the nutrition label to ensure there are no hidden carbohydrates.

For a dairy-free or lighter version, you can use full-fat coconut cream or cashew cream to achieve a rich, creamy texture without the high carbs from milk. Avocado is another keto-friendly, high-fat option for thickening.

You can thicken your soup by using an immersion blender to create a smoother, thicker consistency, or by adding a small amount of a keto-friendly thickener like xanthan gum. Alternatively, simply simmering longer can help it reduce naturally.

Yes, fresh tomatoes are keto-friendly in moderation. They contain relatively few net carbs compared to other fruits. A medium tomato has only around 2-3 grams of net carbs, which is well within a typical daily keto allowance.

Great keto toppings include shredded parmesan cheese, crispy bacon bits or pancetta, fried halloumi cheese cubes, a swirl of heavy cream, or chopped fresh basil.

Tomato paste is more concentrated in carbs than fresh tomatoes, so it should be used sparingly on a keto diet. Always check the label for added sugars, which are common in many store-bought varieties.