Which Type of Tomato Has the Least Amount of Sugar?

October 27, 2025 •

4 min read

While often perceived as a vegetable, tomatoes are botanically a fruit, and their sugar content varies significantly across different varieties. Understanding which type of tomato has the least amount of sugar is key for those monitoring their intake, like individuals with diabetes, as some small, sweet varieties can have nearly double the Brix rating of larger, more acidic ones.

Quick Summary

The type of tomato with the least sugar is generally a large, acidic heirloom variety, such as Beefsteak or Purple Calabash. Smaller, sweeter cherry and grape tomatoes typically have a higher sugar concentration. Factors like ripeness and growing conditions also play a role in the final sugar content.

Key Points

Least Sugar Content: Large, acidic varieties like Beefsteak, Purple Calabash, and Rutgers generally have the least amount of sugar.
High vs. Low: Smaller tomatoes, such as cherry and grape varieties, tend to have a higher sugar concentration due to less water content.
Brix Scale: The Brix scale is used to measure the sugar content; look for varieties with a lower Brix rating.
Growing Conditions Matter: Factors like ripeness, sunlight exposure, and water can influence the final sugar concentration in a tomato.
Dietary Impact: Fresh tomatoes have a low glycemic index and are suitable for low-sugar diets, unlike some processed tomato products with added sugars.
Cooking Preference: Low-sugar tomatoes are excellent for savory applications like sauces, soups, and canning, where natural acidity is a desired flavor.

Demystifying Tomato Sugar Content

When considering the sweetness of a tomato, the general rule is to look for larger, more acidic varieties. The naturally occurring sugars in tomatoes are primarily fructose and glucose. The concentration of these sugars is often measured using the Brix scale, where a higher number indicates a sweeter fruit. Counterintuitively for some, the large, meaty beefsteak tomatoes and many acidic heirlooms typically register lower on this scale compared to their smaller, snackable counterparts.

Heirloom varieties, in particular, are prized for their complex, sometimes more acidic flavor profiles, which often correlate with a lower sugar content. Cultivars known for a more tart or savory taste are a great starting point for those looking to minimize their sugar intake. Conversely, the high Brix ratings of many cherry and grape tomatoes are what make them so popular for salads and snacking, but also what places them higher on the sugar scale.

The Impact of Ripeness and Growing Conditions

Beyond just the variety, other factors critically influence a tomato's sugar level. A tomato's sugar content increases as it ripens, so a slightly under-ripe fruit will naturally have less sugar than a perfectly ripe one. Furthermore, environmental factors can dramatically alter the final flavor and sugar profile. Tomatoes grown in hot climates with consistent water often develop more sugars, whereas those from regions with significant day-to-night temperature swings tend to retain more acidity. How the plant is fertilized and the soil composition can also affect the sugar and acid balance.

Low-Sugar Tomato Variety List

Here are some of the best choices for low-sugar tomatoes, often favored for their acidic or robust, non-sweet flavor profiles:

Beefsteak: These large, meaty tomatoes are a classic choice for low-sugar eating. Their size means the sugar is more diluted, and their flavor is typically more savory and acidic.
Purple Calabash: Known for its striking, dark purple color and distinctively strong, acidic, and complex flavor. It is one of the more acidic heirloom varieties and is low in sugar.
Rutgers: This heirloom variety is praised for its high acidity, which lends itself well to cooking and canning. A favorite for those who appreciate a less sweet tomato.
Druzba: An heirloom known for its rich, tangy flavor and relatively low sugar content compared to modern hybrids.
White Potato Leaf: As the name suggests, this heirloom is notable for its foliage and a flavor profile that is more on the acidic side, placing it in the low-sugar category.
Roma (Paste Tomatoes): These tomatoes are valued for their low water content, and while some varieties can be sweet, many, particularly those used for canning and paste, have a more balanced acid-to-sugar ratio.

Comparing High-Sugar and Low-Sugar Tomatoes


Feature	Low-Sugar Tomatoes	High-Sugar Tomatoes
Typical Varieties	Beefsteak, Purple Calabash, Rutgers	Cherry, Grape, Sungold
Flavor Profile	Savory, acidic, less sweet	Very sweet, sometimes milder
Size	Larger, often meaty	Small, bite-sized
Brix Rating	Lower (e.g., 5-6)	Higher (e.g., 8-10+)
Best Use	Sauces, cooking, sandwiches	Snacking, salads
Nutrient Balance	Higher concentration of acids	Higher concentration of sugars

Cooking with Low-Sugar Tomatoes

Cooking with low-sugar tomatoes allows for greater control over the final flavor of a dish, especially for sauces and soups. The natural acidity can be balanced with other ingredients, creating a rich and complex taste without relying on sweetness. For example, a slow-cooked tomato sauce made with Rutgers or Roma tomatoes will have a deep, savory flavor, perfect for pasta or pizza. When making salsas, opting for a larger, more acidic tomato can produce a fresher, less cloying result.

Furthermore, those on a low-sugar diet or managing conditions like diabetes can benefit from incorporating these varieties. Studies show that fresh tomatoes have a low glycemic index, making them a favorable choice for managing blood sugar levels. However, as always, portion control and preparation matter. Using fresh, whole tomatoes is preferable to canned sauces or juices, which can often contain added sugars and sodium.

Conclusion: Choosing Your Tomato Wisely

For those seeking the tomato with the least amount of sugar, the answer lies among the large, heirloom, and acidic varieties. Beefsteak, Purple Calabash, and Rutgers are all excellent candidates that provide a robust, savory flavor profile while keeping sugar content low. While smaller, sweeter varieties like cherry tomatoes have their place, they are not the best choice for those strictly monitoring their sugar intake. By understanding the varietal differences and paying attention to preparation methods, you can enjoy all the nutritional benefits of tomatoes while adhering to a low-sugar diet.

A Resource for Healthy Eating

For more detailed nutritional information and healthy recipe ideas, a great resource is the U.S. Department of Agriculture FoodData Central database. It provides comprehensive data on thousands of foods, including various tomato products, to help inform your dietary choices.

Frequently Asked Questions

Yes, cherry and grape tomatoes typically have a higher sugar concentration per ounce than larger varieties like beefsteak tomatoes. Their smaller size results in a higher sugar density, giving them a sweeter taste.

The Brix rating is a scale that measures the sugar content in a food item. A higher Brix value indicates more sugar. For tomatoes, varieties with a low Brix score are less sweet, while those with a high score are sweeter.

Yes, fresh tomatoes are generally considered safe and beneficial for people with diabetes. They have a low glycemic index and are rich in fiber and antioxidants. However, it's best to avoid processed tomato products with added sugars.

Many heirloom tomato varieties, especially the more acidic types like Purple Calabash, are known for having lower sugar content and a more complex, savory flavor compared to modern hybrids. However, some heirloom varieties can also be sweet.

Yes, as a tomato ripens, its sugar content increases. A slightly under-ripe tomato will have a lower sugar concentration than one that is fully ripe. This is why some under-ripe tomatoes are tarter.

The cooking process itself doesn't add sugar. However, cooking and concentrating tomatoes, such as in a sauce, reduces their water content, which can make the sugar and flavor more concentrated. Adding sugar is a common practice in many commercial sauces, so checking the label is important.

For cooking savory sauces, paste tomatoes like Roma are a great low-sugar option. Their low water content and balanced flavor profile allow for rich, concentrated sauces without excessive sweetness. Rutgers and other acidic heirlooms are also excellent choices.