Zucchini Glycemic Index
Low GI · The honest verdict
Gentle on blood sugar
Glycemic index
15
per source
Glycemic load
1
Low GL
This food's glycemic index is 15, which is Low GI.
Zucchini is one of the most diabetes-friendly vegetables. With only about 2.7 g of net carbs per cup and a glycemic load of 1, it has virtually no effect on blood sugar. It can be eaten freely as part of a diabetes meal plan. This is general nutrition information, not medical advice — people with diabetes should confirm 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
Zucchini has a glycemic index of about 15 — among the lowest GI values of any vegetable.
One cup of raw sliced zucchini contains only 21 calories and 2.7 g of net carbs.
Zucchini provides 22 mg of vitamin C per cup — about 24% of the daily value.
What's actually inside
Per 100 g, with your typical serving noted as 1 cup (124 g), sliced, raw. The carb family is what moves blood sugar — fiber is the number that softens the spike.
- Total carbs
- 3.9g
- Net carbs
- 2.7g
- total carbs minus fiber
- Fiber
- 1.2g
- slows the glucose rise
- Sugars
- 1.9g
- Protein
- 1.5g
- Calories
- 21kcal
Notable nutrients
- Vitamin C22 mg
- Potassium295 mg
- Manganese0.2 mg
- Vitamin B60.1 mg
- Magnesium22 mg
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, minimal blood sugar impact
Zucchini is one of the most diabetes-friendly vegetables. With only about 2.7 g of net carbs per cup and a glycemic load of 1, it has virtually no effect on blood sugar. It can be eaten freely as part of a diabetes meal plan. This is general nutrition information, not medical advice — people with diabetes should confirm with their care team.
Portion guidance
Portion size is not a meaningful concern with zucchini due to its very low carb content. A full cup of raw sliced zucchini contains less than 3 g of net carbs. Even larger portions — such as an entire medium zucchini (about 2 cups sliced) — provide only about 5–6 g of net carbs, well within any diabetes-friendly eating plan.
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.
Raw consumption
Little effectRaw zucchini has the lowest possible GI because its cell structure is intact and starches are minimal. It provides maximum fiber benefit and requires more chewing, slowing digestion.
Steaming or sautéing
Little effectLight cooking softens zucchini slightly but does not meaningfully raise its GI because it contains very little starch. The glycemic impact remains negligible.
Frying or roasting with oil
Little effectAdding fat does not raise GI. However, if zucchini is breaded or battered before frying, the coating adds significant carbs and raises the overall glycemic impact of the dish.
Zucchini noodles (zoodles)
Little effectSpiralized zucchini retains the same low GI as whole zucchini. It serves as an excellent low-carb pasta substitute, with negligible blood sugar impact compared to wheat pasta.
Pairing tip
Zucchini pairs well with nearly any protein or fat without raising the glycemic impact of the meal. Use it as a base for pasta sauces, add to stir-fries with chicken or tofu, or stuff with ground meat and cheese. Avoid breading or battering zucchini if glycemic control is a priority.
Why GI numbers vary
Zucchini GI is consistently reported around 15 across sources, making it one of the most reliably low-GI foods. The minimal variation comes from differences in cooking method and variety, but all forms of zucchini — raw, steamed, sautéed — remain firmly in the low-GI category. We report a single value of 15 because the data is consistent and well-established.
Not medical advice. This page is general nutrition information about Zucchini. 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
Zucchini has a glycemic index of about 15, which is very low. This means it causes a minimal and slow rise in blood sugar. Because zucchini is mostly water and fiber with very few carbohydrates, its GI is among the lowest of any vegetable. Even cooked zucchini remains in the very low GI range.
Yes, zucchini is excellent for people with diabetes. With only about 2.7 g of net carbs per cup and a glycemic load of 1, it has virtually no effect on blood sugar. It provides vitamin C, potassium, and fiber while being very low in calories. Zucchini can be eaten freely without significantly impacting glucose levels. This is general nutrition information, not medical advice.
Cooking zucchini does not meaningfully raise its GI because it contains very little starch to gelatinize. Raw, steamed, sautéed, or roasted zucchini all remain in the very low GI range. The only way cooking could raise the glycemic impact is if you add high-carb ingredients like breading, batter, or sugary sauces.
Absolutely. Zucchini is a staple vegetable on keto and low-carb diets. One cup contains only about 2.7 g of net carbs, making it easy to fit into even strict keto plans (under 20 g net carbs per day). Zucchini noodles are a popular low-carb substitute for pasta, and zucchini can be used in baking as a low-carb ingredient.
Zucchini is very similar to other summer squash varieties like yellow squash and pattypan squash — all have very low GI values (around 15) and minimal carb content. They are interchangeable for blood sugar management. The key difference is that winter squash (like butternut or acorn) are starchy and have moderate GI, while summer squash are non-starchy and very low GI.
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Reviewed by
Curex Editorial TeamReviewed for accuracy
Last reviewed July 2026