● Food Intelligence · Vegetable

Squash Glycemic Index and Calculate Your Own Glucose Response

Across 17,226 squash logs from 5,762 Signos members, the average glucose peak was +30.7 mg/dL — but squash is really two foods. Spaghetti squash (the pasta substitute) holds at +26 mg/dL, while butternut squash soup runs to +40.2 mg/dL once the bread and bowl join the plate.

GS
Reviewed by Grace Shryack
Signos Proprietary Data·Updated May 20, 2026·10 min read

● Powered by Signos cohort dataHigh confidence · n=17,226
The swap calculator below draws on 17,226 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.
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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.

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Meal Context
Pre-meal sequence
Activity after meal
Time of day
46
of 100
Signos Glucose Score
High Spike Risk
75% of members fall between +28 and +40 mg/dL
Predicted Curve · 3-hr window
1401001201401601800m30m60m90m120m150m180m+34
Peak
+34
mg/dL
Time in Range
100%
3hr window
Above 140
0m
danger zone
Swaps
0
applied
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● Key Findings · Does squash spike blood sugar?

Sometimes — and the form is the lever. Across 17,226 squash logs the average peak was +30.7 mg/dL; spaghetti squash anchors at +26 mg/dL, butternut soup at +40.2 mg/dL. Across 17,226 logged squash meals from 5,762 Signos members, the mean glucose peak was +30.7 mg/dL (median +27 mg/dL). But squash is really two foods in one cohort: summer and spaghetti varieties are mostly water and behave like low-GI vegetables, while butternut, acorn, and kabocha carry more starch. Spaghetti squash averaged +26.2 mg/dL across 3,155 logs — the lowest form. Butternut squash soup climbed to +40.2 mg/dL across 1,202 logs — the highest. Total meal carb load is the other dominant lever: meals with ≥60g carbs ran 46.7% above the lower-carb baseline (CI: +11.88 to +13.61 mg/dL, n=2,655, p<0.001), and the carb-bucket analysis shows a clean escalation from +27.3 mg/dL in light-carb meals (0–40g, n=11,375) to +44.6 mg/dL in very-heavy meals (110g+, n=375) — a 63% jump.

  • ▸Form moves the curve by ~9 mg/dL: spaghetti squash averaged +26.2 mg/dL (n=3,155, high confidence) while butternut anchored at +32.8 mg/dL (n=2,372) — the cleanest within-food swap in the cohort.
  • ▸Butternut squash soup is the highest-spike build measured: averaging +40.2 mg/dL across 1,202 logs versus +29.9 mg/dL for roasted squash alone — a +10 mg/dL jump (high confidence).
  • ▸Carb load dominates everything else: meals with 110g+ carbs averaged +44.6 mg/dL — 63% above the light-carb baseline of +27.3 mg/dL (n=375 vs n=11,375).
  • ▸Morning timing trims the peak: squash meals before 10 am averaged 16.4% lower peaks than later in the day (CI: −6.05 to −4.24 mg/dL, n=1,362, p<0.001).
● Signos Rules

Three citable insights from this recipe's data

Rule 1
"The Spaghetti-Squash Discount"
−6.6 mg/dL vs. butternut
Across 3,155 logs of spaghetti squash, the average peak was +26.2 mg/dL — 6.6 mg/dL below the butternut anchor of +32.8 mg/dL (n=2,372). Spaghetti squash is the lowest-impact form in the cohort and the cleanest pasta substitute we measured; it contributes near-zero digestible carbs versus the ~40g per cup that cooked spaghetti delivers. Yellow / summer squash sits in between at +29.1 mg/dL across 6,050 logs.
Rule 2
"The Soup Penalty"
+10 mg/dL vs. roasted
Butternut squash soup averaged +40.2 mg/dL across 1,202 logs versus +29.9 mg/dL for roasted squash alone — the largest pairing penalty we measured (high confidence). Two mechanisms: blending the squash into a near-purée gelatinizes the starch and accelerates glucose release, and soup is almost always served with bread or crackers that pile onto the meal carb load. Treat butternut soup as a starchy meal, not a vegetable.
Rule 3
"The Carb-Load Penalty"
+63% peak escalation
When squash appears in meals carrying ≥60g of total carbs, the glucose peak runs 46.7% above the lower-carb baseline (n=2,655, p<0.001, CI: +11.88 to +13.61 mg/dL). The very-heavy-carb bucket (110g+, n=375) reaches +44.6 mg/dL — a 63% escalation over light-carb plates (+27.3 mg/dL, n=11,375). Most of that comes from rice, pasta, or bread on the plate alongside the squash, not the vegetable itself.
● Curious about your own?

Curious how your body responds to squash specifically?

Across 17,226 logged squash meals, the average glucose peak was +30.7 mg/dL — but the IQR spans 28 mg/dL (p25: +17, p75: +41), meaning individual responses vary widely. Your own result depends on form (spaghetti vs. butternut), preparation (roasted vs. soup), and meal context. 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 +33 mg/dL.

Driver 1
Form-level starch (butternut/kabocha vs. spaghetti)
+6.6 mg/dL
Butternut anchored at +32.8 mg/dL (n=2,372) vs. spaghetti squash at +26.2 mg/dL (n=3,155) — a 6.6 mg/dL spread from the same vegetable family. Winter squash carries more starch; summer and spaghetti varieties are mostly water.
Driver 2
Meal-level carbohydrates (rice, bread, pasta alongside)
+12.7 mg/dL
The dominant lever: meals with ≥60g carbs ran 46.7% higher than the lower-carb baseline (CI: +11.88 to +13.61 mg/dL, p<0.001, n=2,655). Very-heavy-carb meals (110g+) reached +44.6 mg/dL — a 63% escalation.
Driver 3
Added sugar in glaze, soup, or pie filling (≥20g)
+10 mg/dL
High-sugar squash meals (≥20g added sugar) averaged 34.9% above the low-sugar baseline (CI: +9.1 to +10.97 mg/dL, n=2,245, p<0.001). The Thanksgiving brown-sugar-maple build and squash-pie filling are the failure modes.
● Which bucket are you in?

Some members spike +26.2 mg/dL. Others spike +44.6. The only way to know how you'll spike is to measure with a Signos CGM.

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● What surprised us
What surprised us about squash is how cleanly the cohort splits into two foods. Across 17,226 logs, spaghetti squash held at +26.2 mg/dL — the marquee pasta-substitute story, confirmed in 3,155 matched logs. Butternut soup climbed to +40.2 mg/dL across 1,202 logs — the bread bowl and the gelatinized starch doing the work. Yellow / summer squash sits between at +29.1 mg/dL. Squash isn't one editorial story; it's two. Pick the form that matches your goal, watch the soup, and the response is usually moderate.
— Signos Data Science Team

Why this happens, physiologically

Squash is a wide cohort that spans two physiologic profiles. Summer and spaghetti varieties are ~95% water with minimal starch, behaving like low-GI vegetables; winter varieties (butternut, acorn, kabocha) carry more digestible starch and behave more like a starchy side. Across 17,226 logs the mean glucose peak was +30.7 mg/dL with an IQR of 28 mg/dL (p25: +17, p75: +41). Total meal carb load is the single biggest lever: meals with ≥60g of carbs ran 46.7% above the lower-carb baseline (CI: +11.88 to +13.61 mg/dL, p<0.001), and the carb-bucket escalation reached 63% from light (0–40g, +27.3 mg/dL) to very-heavy (110g+, +44.6 mg/dL). Two secondary modifiers blunt the response: protein pairings ≥15g trimmed peaks by 11.5% (n=13,730, p<0.001) and fat pairings ≥15g by 8.7% (n=10,916, p<0.001). The mechanism for soup specifically is starch gelatinization — pureeing accelerates glucose release — and the effects throughout are observational, not yet causal.

● Three mechanisms explain squash's glucose range

Form, meal carb load, and added sugar each drive measurable shifts in squash's glucose response

  1. Mechanism 1
    −6.6 mg/dL
    Form effect
    Spaghetti squash averaged +26.2 mg/dL across 3,155 logs versus butternut at +32.8 mg/dL (n=2,372) — a 6.6 mg/dL within-food gap. Summer varieties are mostly water; winter varieties carry more starch.
  2. Mechanism 2
    +46.7%
    High meal carb load
    Meals with ≥60g total carbs alongside squash ran 46.7% above the lower-carb baseline (n=2,655, CI: +11.88 to +13.61 mg/dL, p<0.001). The very-heavy-carb bucket (110g+) reached +44.6 mg/dL — a 63% escalation.
  3. Mechanism 3
    +34.9%
    Added sugar (glaze, pie, soup)
    High-sugar squash meals (≥20g) ran 34.9% above the low-sugar baseline (n=2,245, CI: +9.1 to +10.97 mg/dL, p<0.001). The maple-glaze and brown-sugar Thanksgiving builds are the failure modes — and butternut soup's blended starch compounds it.
● Fit Check
Squash is low-to-moderate for blood sugar — until you puree it into soup or top it with maple glaze.
✓ This is for you if
  • ▸You use spaghetti squash as a pasta substitute. The spaghetti form averaged +26.2 mg/dL across 3,155 logs — 6.6 mg/dL below butternut, the lowest-spike form in the cohort.
  • ▸You favor yellow or summer squash. Summer varieties averaged +29.1 mg/dL across 6,050 logs — 3.7 mg/dL below the butternut anchor.
  • ▸You eat squash at breakfast. Morning logs averaged 16.4% below the rest-of-day baseline (CI: −6.05 to −4.24 mg/dL, n=1,362, p<0.001).
  • ▸You keep total meal carbs under 40g. Light-carb squash meals averaged +27.3 mg/dL across 11,375 logs — the lowest carb-bucket in the cohort.
✗ Not for you if
  • ▸You build the meal around butternut squash soup. Soup builds averaged +40.2 mg/dL across 1,202 logs — +10 mg/dL above the roasted-alone baseline, the highest pairing penalty in the cohort.
  • ▸You glaze squash with brown sugar or maple syrup. Glazed builds averaged +33.6 mg/dL across 103 logs (medium confidence); the high-sugar cohort overall ran +34.9% above the low-sugar baseline.
  • ▸You stack squash onto a 110g+ carb plate. Very-heavy-carb meals containing squash averaged +44.6 mg/dL — 63% above the light-carb baseline of +27.3 mg/dL.
  • ▸You default to kabocha over other forms. Kabocha averaged +34.2 mg/dL across 260 logs (medium confidence) — the highest of the form options at +1.4 mg/dL over the butternut anchor.
● How it fits your day

Calorie band and pairings (member-measured)

Per serving
60–1,170 kcal
Ranges from a small roasted side (~60 kcal) to a full butternut-soup meal with bread (~1,170 kcal); single-item logs averaged 249 kcal.
● Pair before
  • ▸Pick spaghetti squash when the goal is a pasta substitute: it averaged +26.2 mg/dL across 3,155 logs — 6.6 mg/dL below the butternut anchor.
  • ▸Keep total meal carbs under 40g: light-carb squash meals averaged +27.3 mg/dL vs. +44.6 mg/dL in the 110g+ carb bucket — a 63% escalation.
● Pair after
  • ▸Time a 15–20 min walk after butternut-soup meals, which averaged +40.2 mg/dL — the highest pairing context measured.
  • ▸Favor morning timing when the menu allows: squash before 10 am averaged 16.4% below the rest-of-day baseline (n=1,362).
● Avoid pairing
  • ▸Avoid the brown-sugar / maple-glaze Thanksgiving build: glazed squash averaged +33.6 mg/dL vs. +29.9 mg/dL roasted alone (+4 mg/dL across 103 logs, medium confidence).
  • ▸Avoid treating butternut soup as a vegetable side — it averaged +40.2 mg/dL across 1,202 logs, +10 mg/dL above roasted squash alone (high 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 squash's glucose response compares to other root and starchy vegetables, plus the pasta and bread it gets paired with
Sweet Potato Glycemic Index & Glucose Score
Sweet potato is the higher-GI root cousin — a starchier comparison point to squash's lower form-by-form profile.
Zucchini Glycemic Index & Glucose Score
Zucchini is summer squash's botanical sibling — glucose-flat on its own, an amplifier of whatever rice or pasta sits next to it.
Cauliflower Glycemic Index & Glucose Score
Cauliflower is the canonical carb-swap vegetable; pair it with spaghetti squash to compare pasta-substitute strategies side by side.
Spaghetti Glycemic Index & Glucose Score
The pasta-swap reference: see what spaghetti does to glucose so you can quantify what spaghetti squash saves you.
Carrots Glycemic Index & Glucose Score
Carrots round out the root-vegetable tier — useful when comparing winter squash's starchier profile to other moderate-GI roots.
Track Your Squash Response with Signos →
See how your glucose reacts to spaghetti squash vs. butternut soup, or a maple-glazed roast vs. plain — CGM data, personalized to you.

Frequently Asked Questions

Methodology

This page draws on 17,226 squash logs from 5,762 unique Signos members, collected through the Signos production CGM platform between March 2025 and April 2026. Data were filtered to postprandial glucose responses (PPGR) between 0 and 100 mg/dL to exclude sensor artifacts and implausible readings. The page-primary cohort is 17,226 logs (median +27 mg/dL, IQR 28 mg/dL); a single-item subset of 944 logs (squash eaten alone) averaged +32.5 mg/dL. 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. The food was identified in member logs using a regex matching "squash" as a primary ingredient, excluding the UK "squash drink" cordial term, the racket sport, and commercial canned-soup brand mentions. Any carb-pair pairing slot requires at least 30 matched meals (high-confidence at ≥500) before it appears in the recipe builder.

Limitations

  • Self-reported portion sizes introduce measurement error — a logged "1 cup" of squash may vary significantly in actual weight, affecting 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.
  • Squash is a wide umbrella covering five distinct varieties (butternut, yellow / summer, kabocha, acorn, spaghetti) with meaningfully different starch profiles — the cohort mean of +30.7 mg/dL averages across all of them, and form-level results are the more useful read.
  • The acorn squash sub-cohort returned only n=20 matched logs and is rated fail-confidence; we report it for completeness but it should not drive editorial conclusions.
  • The brown-sugar / maple-glaze pairing slot is modest (n=103, medium confidence); the +4 mg/dL delta is directionally consistent but the precise magnitude could shift with a larger sample.
  • 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 squash response

Across 17,226 logged squash meals from 5,762 members, the average glucose peak was +30.7 mg/dL — but the IQR spans 28 mg/dL, meaning your personal response could land well above or below that. Form matters enormously: spaghetti squash averaged +26.2 mg/dL, butternut +32.8 mg/dL, butternut soup +40.2 mg/dL. A CGM shows you exactly where you land and which builds work best for your biology.

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