Tomato Glycemic Index
Low GI · The honest verdict
Gentle on blood sugar
Glycemic index
15–30
reported range
Glycemic load
0
Low GL
This food's glycemic index is 15–30, which is Low GI.
Tomatoes are a top choice for blood sugar management. With only about 3.3 g of net carbs per medium fruit and a GI of 15–30, they have a negligible glycemic load and do not cause meaningful blood sugar spikes. This is general nutrition information, not medical advice — people with diabetes should confirm serving guidance with their care team.
GI numbers vary by source, ripeness, and how a food is prepared. This is general nutrition information — not medical advice. If you manage diabetes, confirm specifics with your care team.
Key facts
Tomatoes have a GI of 15–30 — among the lowest of all fruits and vegetables.
One medium tomato provides 16 mg vitamin C — about 18% of the daily value.
Lycopene in tomatoes is better absorbed when cooked with a little oil — and cooking does not meaningfully raise GI.
What's actually inside
Per 100 g, with your typical serving noted as 1 medium tomato (123 g), raw. The carb family is what moves blood sugar — fiber is the number that softens the spike.
- Total carbs
- 4.8g
- Net carbs
- 3.3g
- total carbs minus fiber
- Fiber
- 1.5g
- slows the glucose rise
- Sugars
- 3.2g
- Protein
- 1.1g
- Calories
- 22kcal
Notable nutrients
- Vitamin C16 mg
- Potassium292 mg
- Vitamin A (as beta-carotene)1025 IU
- Lycopene3.2 mg
- Folate18 mcg
Is it a smart choice for blood sugar?
GI is only half the story — portion (glycemic load) and what you eat it with decide the real-world effect. Here's the honest read.
The verdict
Excellent — very low carb, low GI, diabetes-friendly
Tomatoes are a top choice for blood sugar management. With only about 3.3 g of net carbs per medium fruit and a GI of 15–30, they have a negligible glycemic load and do not cause meaningful blood sugar spikes. This is general nutrition information, not medical advice — people with diabetes should confirm serving guidance with their care team.
Portion guidance
A medium raw tomato (about 123 g) has roughly 3.3 g net carbs and a glycemic load near zero, so portion size is not a concern. Even larger servings — such as two whole tomatoes or a cup of cherry tomatoes — remain very low in carbs and glycemic impact. The greater consideration is what you pair them with: tomato-based sauces and soups often include added sugars, which can raise the glycemic load of the meal.
This is general nutrition information, not personal medical advice. Blood sugar responses are individual — if you have diabetes or prediabetes, your care team can tell you how this fits your plan.
How to keep the spike small
The same food can land differently depending on how it's cooked and what it's eaten with. Use these levers to your advantage.
Cooking (sauces, stews, roasting)
Raises GICooking tomatoes breaks down cell walls and concentrates natural sugars slightly, which can modestly increase GI. However, the effect is small — cooked tomatoes remain low-GI. The bigger risk is added sugar in prepared sauces.
Drying (sun-dried tomatoes)
Raises GISun-dried tomatoes have much higher sugar concentration per gram due to water removal, raising GI and GL significantly. A small handful of sun-dried tomatoes has a noticeably higher carb load than a fresh tomato.
Juicing (tomato juice)
Raises GIJuicing removes fiber and concentrates sugars, increasing GI. Commercial tomato juice often contains added salt and sometimes sugar. It is still low-GI relative to fruit juices but higher than whole tomatoes.
Pairing with fat (olive oil in cooking)
Lowers the spikeAdding fat like olive oil slows gastric emptying and can slightly reduce the glycemic response to the meal, even though the tomato itself remains low-GI.
Pairing tip
Tomatoes pair well with nearly anything and do not require special pairing to manage blood sugar. For a balanced meal, combine tomatoes with protein (eggs, chicken, fish, beans) and healthy fats (avocado, olive oil). Avoid heavy sweetening in tomato sauces — opt for herbs and garlic instead. Tomato and avocado is an excellent low-carb, high-nutrient combination.
Why GI numbers vary
Tomato GI values are consistently reported in the low range (15–30) across sources, with minor variation depending on variety (cherry vs. Roma vs. beefsteak) and ripeness. Riper tomatoes contain slightly more sugar, which can push GI toward the higher end of the range, but they remain low-GI. Cooking and processing have a more meaningful effect than variety differences. We report the honest range (15–30) and classify tomatoes as low because all credible sources place them well below 55.
Not medical advice. This page is general nutrition information about Tomato. It isn't a diagnosis or a treatment plan. If you have diabetes, prediabetes, or another condition affecting blood sugar, confirm any dietary decisions with your doctor or care team.
Frequently Asked Questions
The glycemic index of a raw tomato is approximately 15–30, depending on variety and ripeness. This is classified as low GI (below 55). Tomatoes are very low in carbohydrates — about 3.3 g net carbs per medium fruit — so they have a negligible glycemic load. Even cooked tomatoes remain low-GI as long as no sugar is added. This makes them one of the most blood-sugar-friendly fruits available.
Yes, tomatoes are excellent for people with diabetes. They are very low in carbs (about 3.3 g net carbs per medium tomato), have a low GI (15–30), and provide important nutrients like vitamin C, potassium, and lycopene. They do not cause blood sugar spikes and can be eaten freely as part of a diabetes-friendly diet. The only caveat is to watch for added sugars in processed tomato products like ketchup, pasta sauce, and tomato soup.
Plain tomato sauce (no added sugar) has a GI similar to whole tomatoes — low. However, most commercial pasta sauces and ketchups contain added sugar, which raises their GI and GL significantly. A tablespoon of ketchup contains about 4 g of carbs (mostly sugar), giving it a moderate GI. For blood sugar management, choose no-sugar-added tomato products or make your own.
Yes, cherry tomatoes are low in carbs — about 2.5 g net carbs per half-cup (75 g). They fit easily into low-carb and even keto diets in reasonable portions. A cup of cherry tomatoes contains roughly 5 g net carbs, which is manageable on most low-carb plans. They are a popular choice for salads, snacks, and roasting on low-carb diets.
Yes, ripeness has a modest effect. Riper tomatoes contain more simple sugars (glucose and fructose) and less starch, which can raise GI slightly. However, the difference is small — both unripe green tomatoes and fully ripe red tomatoes remain in the low-GI range. The effect of ripeness on GI is much less significant for tomatoes than for fruits like bananas or mangoes.
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Reviewed by
Curex Editorial TeamReviewed for accuracy
Last reviewed July 2026