● Food Intelligence · Vegetable

Zucchini Glycemic Index and Calculate Your Own Glucose Response

Across 19,935 zucchini meals from 6,046 Signos members, the average glucose peak was +28.2 mg/dL — but zucchini itself is essentially glucose-flat. The signal is almost entirely the meal context: light-carb meals (0–40g) hold at +25.2 mg/dL while very-heavy-carb meals (110g+) escalate to +42.0 mg/dL, a 67% jump driven by the pasta, rice, or grain bowl alongside it.

GS
Reviewed by Grace Shryack
Signos Proprietary Data·Updated May 02, 2026·10 min read

● Powered by Signos cohort dataHigh confidence · n=19,935
The swap calculator below draws on 19,935 matched-pair logs — a broader cohort than the page's single-item primary, used to give every ingredient swap statistical power. Welch's t-test on matched pairs, not third-party glycemic-index tables. Each swap shows its sample size and confidence tier inline.
● FREE SIGNOS TOOL

Build Your Own Low GI Recipe

Powered by 19,935
Signos food logs

Tap any ingredient below to swap it for a glucose-friendlier alternative. Your Signos Glucose Score, predicted curve, and nutrition update in real-time. Every swap is data-backed by real CGM response measurements.

Ingredients — Tap to Swap
Meal Context
Pre-meal sequence
Activity after meal
Time of day
38
of 100
Signos Glucose Score
Moderate Spike Risk
75% of members fall between +23 and +33 mg/dL
Predicted Curve · 3-hr window
1401001201401601800m30m60m90m120m150m180m+28
Peak
+28
mg/dL
Time in Range
100%
3hr window
Above 140
0m
danger zone
Swaps
0
applied
Want your real response?
Predictions are cohort averages. Wear a CGM to see your actual response.
Get a Signos CGM →
● Key Findings · Does zucchini spike blood sugar?

No — not on its own. Zucchini is glucose-flat (GI 15, GL 0); the +28.2 mg/dL cohort average across 19,935 logs is driven by what's on the plate alongside it. Across 19,935 logged zucchini meals from 6,046 Signos members, the average glucose peak was +28.2 mg/dL (median +24 mg/dL). But the carb load of the surrounding meal is the dominant driver: meals with ≥60g of carbs spiked 51% higher than the lower-carb baseline (+13 mg/dL, n=2,418, p<0.001), and the carb-bucket analysis shows a clean escalation from +25.2 mg/dL in light meals (0–40g, n=14,336) to +42.0 mg/dL in very-heavy meals (110g+, n=353) — a 67% jump. Rice and grain pairings added +9 mg/dL; stir-fries added +8 mg/dL. Cheese pairings (parmesan, gratin) added effectively zero (+0 mg/dL, n=4,248).

  • ▸The carb-load effect dominates: meals with 110g+ carbs averaged +42.0 mg/dL — 67% above the light-carb baseline of +25.2 mg/dL (n=353 vs n=14,336).
  • ▸Rice and grain bowls add the biggest carb-pair penalty: zucchini with rice or in a grain bowl averaged +36.2 mg/dL vs +27.4 mg/dL alone (+9 mg/dL across 1,945 logs, high confidence).
  • ▸Cheese pairings are a wash: parmesan, gratin, and other cheese pairings averaged +27.2 mg/dL — a flat zero delta from the zucchini-alone baseline (n=4,248, high confidence).
  • ▸Morning timing lowers the spike: zucchini meals before 10am averaged 22% lower peaks than the rest of the day (CI: −7.13 to −5.7 mg/dL, n=2,095, p<0.001).
● Signos Rules

Three citable insights from this recipe's data

Rule 1
"The Carb-Load Penalty"
+51% peak
When zucchini appears in a meal with ≥60g of carbs, the glucose peak runs 51% above the lower-carb baseline (n=2,418, p<0.001). Zucchini itself contributes near-zero digestible carbs; every point of that 51% comes from the rice, pasta, or grain bowl on the plate alongside it. The very-heavy-carb bucket (110g+) reaches +42.0 mg/dL — a 67% escalation over light-carb meals.
Rule 2
"The Cheese Wash"
+0 mg/dL vs. zucchini alone
Pairing zucchini with cheese — parmesan, gratin, or melted on top — produced a flat zero delta against the zucchini-alone baseline across 4,248 matched meals. Cheese contributes fat and protein but almost no carbs, so the meal's glucose curve looks identical to plain zucchini. This is the rare carb-pair option that's truly neutral.
Rule 3
"The Morning Edge"
−22% peak
Zucchini logged before 10am averages 22% lower peaks than the same food logged later in the day (n=2,095 morning vs. n=15,880 non-morning, p<0.001). Breakfast meals containing zucchini averaged just +23.4 mg/dL — the lowest of any meal-time slot — versus +29.5 mg/dL at dinner. Earlier insulin sensitivity likely drives the gap, though the effect is observational.
● Curious about your own?

Curious how your body responds to zucchini specifically?

Across 19,935 logged zucchini meals, the average glucose peak was +28.2 mg/dL — but the IQR spans 23 mg/dL (p25: +15, p75: +38), meaning individual responses vary enormously. Your own result depends on meal context, carb pairing, and metabolic state. A CGM tells you which side of that range you actually land on.

Learn how Signos works
Why this meal spikes

This meal stacks 3 independent spike drivers — together they account for +27 mg/dL.

Driver 1
Meal-level carbohydrates (rice, pasta, grain bowls)
+13 mg/dL
The dominant lever: meals with ≥60g carbs ran 51% higher than the lower-carb baseline (p<0.001, n=2,418). Zucchini is glucose-flat (GI 15, GL 0), so this effect is entirely from what it's eaten with.
Driver 2
Meal composition and caloric load (avg 329 kcal alone vs 473 kcal paired)
+6 mg/dL
Single-item logs averaged +28.1 mg/dL vs +28.2 mg/dL in multi-item meals — the carb composition matters more than calorie count, but larger plates still tend to deliver more digestible carbs alongside the vegetable.
Driver 3
Individual glucose variability (IQR 23 mg/dL)
+5 mg/dL
The interquartile range spans 23 mg/dL (p25: +15, p75: +38), meaning personal metabolic state — insulin sensitivity, microbiome, stress — accounts for a substantial portion of any given reading.
● Which bucket are you in?

Some members spike +25.2 mg/dL. Others spike +42. The only way to know how you'll spike is to measure with a Signos CGM.

See Signos Plans
S
● What surprised us
What surprised us about zucchini is how cleanly it functions as a carb amplifier — not a carb itself. Across 19,935 logs, zucchini eaten alone averaged +27.4 mg/dL. Pair it with rice or a grain bowl and the peak climbs to +36.2 mg/dL. Drop it into a stir-fry and you're at +35.7 mg/dL. But pair it with cheese — parmesan on top, baked into a gratin — and the response is flat: +27.2 mg/dL. Zucchini's editorial story is the swap: zoodles instead of spaghetti, sautéed slices instead of rice. The vegetable itself is glucose-flat; what surrounds it is the entire signal.
— Signos Data Science Team

Why this happens, physiologically

Zucchini is a near-zero-carb vegetable — a published GI of 15, a glycemic load of 0, and roughly 3g of net carbs per cup raw — so its modest baseline peak of +28.2 mg/dL across 19,935 logs is driven almost entirely by meal context. The single biggest lever measured in the cohort is total meal carb load: meals with ≥60g of carbs ran 51% higher than the lower-carb baseline (p<0.001), and the carb-bucket analysis shows a clean escalation from +25.2 mg/dL in light (0–40g) meals to +42.0 mg/dL in very-heavy (110g+) meals — a 67% jump. Two secondary levers pull in the opposite direction: protein pairings (≥15g) trimmed the response by ~6% and fat pairings (≥15g) by ~4%, both significant. The mechanism is observational, not yet causal, but the pattern is consistent with carb load being the primary driver and fat/protein co-ingestion blunting the excursion.

● Three mechanisms explain zucchini's glucose range

Meal carb load, protein co-ingestion, and meal timing each drive measurable shifts in zucchini's glucose response

  1. Mechanism 1
    +51%
    High carb co-load
    Meals logged with ≥60g total carbs showed peaks 51% above the lower-carb baseline (n=2,418, p<0.001). Zucchini itself adds almost no digestible carbs — every point of that 51% comes from the rice, pasta, or grain bowl on the plate alongside it.
  2. Mechanism 2
    −6%
    Protein co-ingestion
    Protein pairings ≥15g cut the response by ~6% across 17,125 matched logs (CI: −2.91 to −0.79 mg/dL, p<0.001). Protein delays gastric emptying, blunting the excursion from any co-ingested carbs.
  3. Mechanism 3
    −22%
    Morning timing
    Zucchini logged before 10am ran 22% below the rest-of-day baseline (n=2,095, p<0.001). Breakfast meals averaged +23.4 mg/dL — the lowest meal-time slot. Earlier insulin sensitivity likely drives the gap.
● Fit Check
Zucchini is a glucose-flat vegetable that works well for blood sugar — until the rice, pasta, or grain bowl alongside it doesn't.
✓ This is for you if
  • ▸You use zucchini as a low-carb pasta swap. Zoodles and pasta-sub builds averaged +30.7 mg/dL — only +3 mg/dL above the zucchini-alone baseline across 955 logs.
  • ▸You pair zucchini with cheese. Parmesan, gratin, and melted-cheese builds averaged +27.2 mg/dL — a flat zero delta from zucchini alone (n=4,248, high confidence).
  • ▸You eat zucchini at breakfast. Morning logs averaged +23.4 mg/dL — the lowest meal-time slot and 22% below the rest-of-day baseline (n=2,095, p<0.001).
  • ▸You keep total meal carbs under 40g. Light-carb zucchini meals averaged just +25.2 mg/dL — the lowest carb bucket in the cohort across 14,336 logs.
✗ Not for you if
  • ▸You build a rice or grain bowl around zucchini. Rice/grain pairings added +9 mg/dL over the alone baseline (treatment mean +36.2 mg/dL, n=1,945, high confidence).
  • ▸You drop zucchini into a stir-fry. Stir-fry meals averaged +35.7 mg/dL — a +8 mg/dL delta over zucchini alone (n=79, low confidence).
  • ▸You serve zucchini alongside a 110g+ carb meal. Very-heavy-carb meals with zucchini averaged +42.0 mg/dL — 67% above the light-carb baseline of +25.2 mg/dL.
  • ▸You go heavy on stuffed zucchini boats with grain or rice fillings. Stuffed builds averaged +35 mg/dL — +7.3 mg/dL above the sautéed default (n=44, low confidence).
● How it fits your day

Calorie band and pairings (member-measured)

Per serving
30–470 kcal
Ranges from a small sautéed side (~30 kcal) to a stuffed-zucchini main (~470 kcal); single-item logs averaged 329 kcal.
● Pair before
  • ▸Swap zoodles for spaghetti when the goal is a lower-carb pasta meal: pasta-sub builds added only +3 mg/dL over the zucchini-alone baseline (n=955, high confidence).
  • ▸Keep total meal carbs under 40g: light-carb zucchini meals averaged +25.2 mg/dL vs. +42 mg/dL in the 110g+ carb bucket — a 67% escalation.
● Pair after
  • ▸Time a 15–20 min walk after rice or grain-bowl meals with zucchini, which averaged +36.2 mg/dL — the highest carb-pair spike in the cohort.
  • ▸Favor morning timing when possible: zucchini at breakfast averaged +23.4 mg/dL vs. +29.5 mg/dL at dinner.
● Avoid pairing
  • ▸Avoid pairing zucchini with rice or grain bowls when targeting a flat response: that combination added +9 mg/dL over the alone baseline (treatment mean +36.2 mg/dL, n=1,945).
  • ▸Avoid stuffed zucchini built on a grain or rice filling — stuffed builds averaged +35 mg/dL, +7.3 mg/dL above the sautéed default (n=44, low confidence).
● Quick definitions (click to expand)
mg/dL — milligrams per deciliter. The unit blood glucose is measured in. A rise of "+30 mg/dL above baseline" means blood sugar went up 30 units after the meal.
Glycemic Index (GI) — a 0–100 score for how fast a food raises blood sugar in lab tests. Under 55 = low, 56–69 = medium, 70+ = high.
Glycemic Load (GL) — GI adjusted for portion size. Under 10 = low, 10–19 = medium, 20+ = high.
CGM — Continuous Glucose Monitor. A wearable sensor that tracks blood glucose every few minutes. Signos members wear CGMs while eating meals they log.
● Related Foods: How zucchini's glucose response compares to other low-glycemic vegetables and the carbs it gets paired with
Cucumber Glycemic Index & Glucose Score
Cucumber and zucchini sit in the same low-GI vegetable tier — both glucose-flat on their own, both amplifiers of the carbs around them.
Broccoli Glycemic Index & Glucose Score
Broccoli is another GL=0 vegetable that follows the same pattern as zucchini: the cohort signal reflects the rice or grain bowl alongside it.
Cauliflower Glycemic Index & Glucose Score
Cauliflower is the canonical carb-swap vegetable (cauli-rice, cauli-pizza). Compare its low-GI behavior to zucchini's pasta-swap angle.
Spinach Glycemic Index & Glucose Score
Spinach rounds out the low-GI leafy-vegetable tier — useful as a zucchini alternative in stir-fries and salads.
Spaghetti Glycemic Index & Glucose Score
The carb-swap reference: see what spaghetti does to glucose so you can quantify what zoodles save you.
Track Your Zucchini Response with Signos →
See how your glucose reacts to zoodles vs. spaghetti, or zucchini in a grain bowl vs. alone — CGM data, personalized to you.

Frequently Asked Questions

Methodology

This page draws on 19,935 zucchini logs from 6,046 unique Signos members, collected through the Signos production CGM platform. Data were filtered to postprandial glucose responses (PPGR) between 0 and 100 mg/dL to exclude sensor artifacts and implausible readings. Modifier effects were estimated using Welch's t-test on matched pairs against a defined baseline; all reported effects carry p<0.001 unless noted. We report mean glucose peak across a right-skewed distribution — the median spike of +24 mg/dL is a few mg/dL lower than the mean of +28.2 mg/dL, which is typical for this type of data. The food was identified in member logs using a regex matching "zucchini" or "courgette" as a primary ingredient, excluding compound dishes like zucchini bread, zucchini cake, and zucchini muffins where the baked-good carrier dominates the response. Any carb-pair pairing slot requires at least 30 matched meals before it appears in the recipe builder.

Limitations

  • Self-reported portion sizes introduce measurement error — a logged "1 cup" of zucchini may vary significantly in actual weight, affecting the accuracy of per-serving spike estimates.
  • Cohort skews health-motivated; Signos members actively tracking glucose tend to eat more mindfully than the general population, so real-world average spikes may differ.
  • The spiralized-zoodles sub-cohort was too small (n=14) to publish as a standalone form delta, even though zoodles are a marquee zucchini use case. We trust the published GI=15/GL=0 reference for this form.
  • The raw-zucchini sub-cohort returned zero matches in our cohort — a known limitation of self-logged data, where members rarely log raw vegetables as standalone meals.
  • The stuffed-zucchini sub-cohort has low confidence (n=44); treat its +7.3 mg/dL delta vs. sautéed as a directional estimate pending a larger sample.
  • The stir-fry carb-pair sub-cohort has low confidence (n=79); treat its +8 mg/dL delta as directional only.
  • Modifier analyses reflect meal-level correlations, not controlled feeding trials — causality cannot be established from observational CGM data alone.
● Get your own data

See your own zucchini response

Across 19,935 logged zucchini meals from 6,046 members, the average glucose peak was +28.2 mg/dL — but the IQR spans 23 mg/dL, meaning your personal response could land well above or below that. Pairings matter enormously: a rice bowl adds +9 mg/dL, a stir-fry adds +8 mg/dL, while cheese pairings are a flat zero. A CGM shows you exactly where you land and which builds work best for your biology.

Start with Signos
50,000+
Members Measuring