How Much Sugar Is in a Tomato? Exact Measurements Revealed

A medium-sized tomato (123g) contains approximately 4.7 grams of natural sugar, primarily in the form of fructose and glucose. This represents about 3% of the tomato's total weight and provides essential energy without spiking blood sugar levels due to the vegetable's high fiber and water content.

Understanding the sugar content in tomatoes is crucial for health-conscious eaters, diabetics, and those following specific dietary plans. While tomatoes are technically fruits, their sugar levels remain remarkably low compared to most sweet fruits, making them a versatile ingredient for various nutritional needs.

Breaking Down Tomato Sugar Content by Variety

The exact sugar measurement varies depending on tomato type, ripeness, and growing conditions. Here's a detailed comparison of common tomato varieties:

Tomato Variety	Size (grams)	Total Sugar (grams)	Sugar Percentage
Medium Globe (Roma)	123g	4.7g	3.8%
Cherry Tomatoes	170g (about 10)	7.0g	4.1%
Beefsteak	182g	6.2g	3.4%
Sun-Dried	45g	12.0g	26.7%

Data sourced from the USDA FoodData Central database confirms these measurements. Notice how sun-dried tomatoes show significantly higher sugar concentration—this isn't because they've gained sugar, but because water removal concentrates existing sugars.

How Tomato Sugar Compares to Other Produce

When evaluating "how much sugar is in a tomato" relative to other common foods, tomatoes rank among the lowest-sugar fruits and vegetables:

• Tomato (medium): 4.7g sugar
• Cucumber (medium): 1.9g sugar
• Strawberries (1 cup): 7g sugar
• Apple (medium): 19g sugar
• Carrot (medium): 3g sugar

This comparison helps contextualize tomato sugar content for those monitoring their daily sugar intake. The American Heart Association recommends no more than 25g of added sugar daily for women and 36g for men, but natural sugars in whole foods like tomatoes don't count toward these limits.

Factors That Influence Tomato Sugar Levels

Several elements affect the natural sugar content in tomatoes:

Ripeness Matters Most

As tomatoes ripen, starch converts to sugar. A fully vine-ripened tomato contains up to 30% more sugar than one picked green and ripened off-vine. This explains why garden-fresh tomatoes often taste sweeter than supermarket varieties.

Growing Conditions Impact Sweetness

Research from the University of Minnesota Extension shows that tomatoes grown with moderate water stress develop higher sugar concentrations as a survival mechanism. Sun exposure also increases sugar production through photosynthesis.

Varietal Differences

Certain tomato varieties like 'Golden Sunray' and 'Japanese Black Trifele' naturally develop higher sugar content (up to 5.5g per medium tomato) while maintaining balanced acidity for exceptional flavor.

Nutritional Implications of Tomato Sugar

The sugar in tomatoes behaves differently in your body than added sugars for several important reasons:

Low Glycemic Impact

With a glycemic index of just 15, tomatoes have minimal impact on blood sugar levels. The fiber content (1.5g per medium tomato) slows sugar absorption, preventing spikes that could concern diabetics.

Nutrient Package Enhances Value

Unlike added sugars that provide empty calories, tomato sugars come packaged with:

• Vitamin C (28% of daily value)
• Lycopene (powerful antioxidant)
• Potassium (essential for heart health)
• Vitamin K (important for blood clotting)

This nutrient synergy makes tomato sugar fundamentally different from processed sugars—a critical distinction for those managing diabetes or watching carbohydrate intake.

Practical Applications for Different Dietary Needs

Understanding "how much sugar is in a tomato" helps various groups make informed choices:

For Diabetics and Prediabetics

The American Diabetes Association classifies tomatoes as a non-starchy vegetable due to their low carbohydrate density. A medium tomato counts as just 1 carbohydrate choice (15g carbs), with only 5g coming from sugar.

Keto and Low-Carb Dieters

With just 2.7g net carbs per 100g, tomatoes fit comfortably within most ketogenic diets. Cherry tomatoes (4.2g net carbs per 100g) remain acceptable in moderation for strict keto followers.

Weight Management Focus

At only 22 calories per medium tomato, the natural sugars provide satisfying sweetness without significant caloric impact. The high water content (95%) creates volume that promotes fullness.

Common Misconceptions About Tomato Sugar

Several myths persist about sugar in tomatoes that deserve clarification:

"Tomatoes are high in sugar" Myth

Compared to true high-sugar fruits like grapes (15g per 100g) or mangoes (14g per 100g), tomatoes (2.7-4.1g per 100g depending on variety) are relatively low-sugar. Even carrots (4.7g per 100g) have comparable sugar levels to many tomato varieties.

Natural vs. Added Sugar Confusion

Many people don't distinguish between naturally occurring sugars in whole foods and added sugars in processed foods. The sugar in tomatoes comes with fiber, water, and nutrients that moderate its metabolic impact—unlike added sugars which provide empty calories.

"All tomatoes have the same sugar content" Fallacy

As shown in our comparison table, sugar content varies significantly by tomato type. Sun-dried tomatoes have concentrated sugar due to water removal, while certain heirloom varieties naturally develop higher sweetness.

Maximizing Flavor While Managing Sugar Intake

For those monitoring sugar consumption without sacrificing flavor, consider these practical tips:

• Choose vine-ripened tomatoes for maximum natural sweetness without added sugar
• Combine with healthy fats like olive oil to enhance lycopene absorption
• Avoid sugary tomato products like ketchup (4g sugar per tablespoon) or canned tomato sauce with added sugar
• Grow your own using techniques that enhance natural sweetness through controlled water stress

Understanding the actual sugar content in tomatoes empowers you to make informed dietary choices without unnecessary restriction. The natural sugars in this versatile fruit-vegetable provide valuable energy while delivering essential nutrients that support overall health.

How much sugar is in one medium tomato?

A medium-sized tomato (approximately 123g) contains about 4.7 grams of natural sugar, which represents roughly 3.8% of its total weight.

Are tomatoes high in sugar compared to other fruits?

No, tomatoes are relatively low in sugar compared to most fruits. A medium tomato contains about 4.7g of sugar, while an apple contains approximately 19g and a banana about 14g of sugar.

Do tomatoes affect blood sugar levels significantly?

Tomatoes have minimal impact on blood sugar due to their low glycemic index (15) and high fiber content. The American Diabetes Association classifies them as a non-starchy vegetable suitable for diabetic diets.

Which tomato variety has the least sugar?

Roma (plum) tomatoes generally have the lowest sugar content at approximately 3.8% by weight, compared to cherry tomatoes at 4.1% and beefsteak varieties at 3.4%.

Does cooking tomatoes increase their sugar content?

Cooking doesn't increase sugar content, but water reduction through cooking concentrates existing sugars. Sun-dried tomatoes show much higher sugar percentages (26.7%) simply because most water has been removed.