Food Intelligence · Vegetable

Radish Glycemic Index and Calculate Your Own Glucose Response

Across 4,935 radish logs from 1,690 Signos members, the average glucose peak was +28.3 mg/dL — radish itself is glucose-flat (GI 15, GL 0). Sliced thin on a salad held at +27.1 mg/dL; daikon as banchan / kimchi ran +38 mg/dL; the French butter-on-baguette snack averaged +29.7 mg/dL.

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

● Powered by Signos cohort dataHigh confidence · n=4,935
The swap calculator below draws on 4,935 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.
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Meal Context
Pre-meal sequence
Activity after meal
Time of day
39
of 100
Signos Glucose Score
Moderate Spike Risk
75% of members fall between +24 and +34 mg/dL
Predicted Curve · 3-hr window
1401001201401601800m30m60m90m120m150m180m+29
Peak
+29
mg/dL
Time in Range
100%
3hr window
Above 140
0m
danger zone
Swaps
0
applied
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● Key Findings · Does radish spike blood sugar?

No — not on its own. Radish is glucose-flat (GI 15, GL 0); the +28.3 mg/dL cohort average across 4,935 logs comes from the butter-and-baguette, the kimchi context, or the taco's corn tortilla. Across 4,935 logged radish meals from 1,690 Signos members, the mean glucose peak was +28.3 mg/dL (median +24 mg/dL). Radish's published GI is 15 and GL is 0 — it's one of the lowest-glycemic vegetables available. The cohort spike tracks meal context: sliced thin on a salad, radishes held at +27.1 mg/dL across 1,062 logs (a −1 mg/dL discount vs. radish alone, high confidence). The butter-on-baguette French snack ran +29.7 mg/dL across 381 logs. Daikon banchan / kimchi climbed to +38 mg/dL across 152 logs — the baseline rice on the side does most of the work. The taco garnish was +33.5 mg/dL across 41 logs (low confidence) — again, the corn tortilla. Carb load is the dominant compounding lever: meals with ≥60g carbs ran 52.3% above the lower-carb baseline (CI: +11.39 to +14.59 mg/dL, n=744, p<0.001), and very-heavy-carb meals reached +42.4 mg/dL — a 71% escalation over light-carb plates.

  • The sliced-on-salad context is essentially flat: radishes on a salad averaged +27.1 mg/dL across 1,062 logs — a −1 mg/dL discount vs. radish alone (high confidence).
  • Daikon runs hotter than red radish: daikon averaged +35.1 mg/dL across 267 logs vs. +27.7 mg/dL for red breakfast radishes — a +7.4 mg/dL gap (medium confidence) likely reflecting Asian-dish carb context.
  • The kimchi-banchan build is the highest pairing measured: radish kimchi averaged +38.0 mg/dL across 152 logs vs. +27.9 mg/dL for radish alone — +10 mg/dL (medium confidence) driven by the rice-on-the-side context.
  • Carb load drives a 71% escalation: very-heavy-carb meals (110g+) averaged +42.4 mg/dL vs. +24.8 mg/dL in light-carb meals (n=143 vs n=3,386).
● Signos Rules

Three citable insights from this recipe's data

Rule 1
"The Salad Discount"
−1 mg/dL vs. radish alone
Across 1,062 logs of radishes sliced thin on a salad, the average peak was +27.1 mg/dL — a small −1 mg/dL discount vs. radish alone (high confidence). The salad context (greens, oil, vinegar, maybe protein) does not add to the radish's already-flat response; if anything it nudges the peak fractionally lower. This is the rare pairing where the build truly is what the vegetable promises.
Rule 2
"The Kimchi-Banchan Tax"
+10 mg/dL vs. radish alone
Radish kimchi or banchan averaged +38.0 mg/dL across 152 logs versus +27.9 mg/dL for radish alone — the largest single carb-pair penalty in the cohort (medium confidence). Fermented radish itself is low-GI; the spike comes from the bowl of rice that almost always rides alongside Korean meals. Treat banchan as a rice meal that includes radish, not a radish meal.
Rule 3
"The Carb-Load Penalty"
+71% peak escalation
When radishes appear in meals carrying ≥60g of total carbs, the glucose peak runs 52.3% above the low-carb baseline (n=744, p<0.001, CI: +11.39 to +14.59 mg/dL). The very-heavy-carb bucket (110g+, n=143) reaches +42.4 mg/dL — a 71% escalation over light-carb plates (+24.8 mg/dL, n=3,386). Radish itself contributes near-zero digestible carbs; every point of that 71% comes from the bread, rice, or tortilla on the plate.
● Curious about your own?

Curious how your body responds to radishes specifically?

Across 4,935 logged radish meals, the average glucose peak was +28.3 mg/dL — but the IQR spans 23 mg/dL (p25: +15, p75: +38), and that range is driven almost entirely by what radishes get eaten with. The salad context holds at +27.1 mg/dL; the kimchi-rice context runs to +38 mg/dL. A CGM tells you which side of that range your biology lands on.

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Why this meal spikes

This meal stacks 3 independent spike drivers — together they account for +28 mg/dL.

Driver 1
Meal-level carbohydrates (≥60g when paired)
+13 mg/dL
The dominant lever: meals with ≥60g carbs alongside radishes ran 52.3% higher than the low-carb baseline (CI: +11.39 to +14.59 mg/dL, n=744, p<0.001). Radish is GI 15; this entire effect comes from what the plate is built around.
Driver 2
Refined-starch carriers (baguette, tortilla, rice)
+10 mg/dL
Radish kimchi / banchan averaged +38 mg/dL (n=152) vs. +27.9 mg/dL alone — a +10 mg/dL jump from the rice-on-the-side context. The taco garnish ran +33.5 mg/dL (n=41) on the corn tortilla; butter-on-baguette ran +29.7 mg/dL (n=381) on the bread.
Driver 3
High-sugar meal context (≥20g sugar)
+8.5 mg/dL
Meals with ≥20g total sugar alongside radish ran 33.9% above the low-sugar baseline (CI: +7.23 to +10.47 mg/dL, n=699, p<0.001). Sweet pickles, sweet-chili dressings, and dessert-side builds drive this.
● Which bucket are you in?

Some members spike +24.8 mg/dL. Others spike +42.4. The only way to know how you'll spike is to measure with a Signos CGM.

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What surprised us
What's worth knowing about radishes is how cleanly the cohort confirms the published GI=15. Across 4,935 logs, sliced-on-a-salad radishes averaged +27.1 mg/dL — a small discount versus radishes alone. Radish itself is glucose-flat. What changes the curve is everywhere a radish travels: the buttered baguette under the French snack (+29.7 mg/dL), the kimchi rice-on-the-side (+38.0 mg/dL), the corn tortilla under the Mexican garnish (+33.5 mg/dL). The vegetable is innocent; the carrier is the story.
Signos Data Science Team

Why this happens, physiologically

Radish is one of the lowest-impact foods in the atlas — published GI of 15, glycemic load of 0, and roughly 1g of net carbohydrate per cup sliced. Across 4,935 logs the mean glucose peak was +28.3 mg/dL with 40.6% of meals registering in the low-spike category (under 20 mg/dL). The +28.3 mg/dL average therefore reflects meal context, not the radish itself. The single biggest lever measured is total meal carb load: meals with ≥60g of carbs ran 52.3% above the low-carb baseline (CI: +11.39 to +14.59 mg/dL, p<0.001), and the carb-bucket analysis shows a 71% escalation from light (0–40g, +24.8 mg/dL) all the way to very-heavy (110g+, +42.4 mg/dL). Two secondary modifiers blunt the response: morning timing trimmed the peak by 11.3% (n=317, p<0.01) and elevated baseline glucose (≥110 mg/dL) by 7.8% (n=1,260). The mechanism is observational, not yet causal, but the pattern is clear: radish the vegetable is glucose-flat; the kimchi rice, the baguette, and the corn tortilla do the work.

● Three mechanisms explain radish's glucose range

Meal carb load, the refined-starch carrier, and morning timing each drive measurable shifts in radish's glucose response

  1. Mechanism 1
    +52.3%
    High meal carb load
    Meals with ≥60g total carbs alongside radish peaked 52.3% above the low-carb baseline (n=744, p<0.001). Radish itself adds almost no carbs — every point of that 52.3% comes from what it's eaten with.
  2. Mechanism 2
    +10 mg/dL
    Refined-starch carrier
    Radish kimchi / banchan averaged +38 mg/dL across 152 logs versus +27.9 mg/dL alone — a +10 mg/dL premium from the rice on the side. The taco garnish (+33.5 mg/dL on corn tortilla) and butter-on-baguette (+29.7 mg/dL on bread) tell the same story.
  3. Mechanism 3
    −11.3%
    Morning timing
    Radish meals logged before 10 am ran 11.3% below the rest-of-day baseline (n=317, CI: −5.17 to −1.31 mg/dL, p<0.01), consistent with stronger morning insulin sensitivity. Effect is small but reliable.
● Fit Check
Radish is a glucose-flat vegetable that works for almost every glucose strategy — the lever is the bread, tortilla, or rice that rides along with it.
This is for you if
  • You slice radishes thin onto a salad. That build averaged +27.1 mg/dL across 1,062 logs — a −1 mg/dL discount vs. radish alone (high confidence).
  • You favor red breakfast radishes over daikon. Red radishes averaged +27.7 mg/dL across 3,293 logs vs. +35.1 mg/dL for daikon — a 7.4 mg/dL gap driven by the Asian-dish carb context daikon usually appears in.
  • You eat radishes at breakfast. Morning logs averaged 11.3% below the rest-of-day baseline (CI: −5.17 to −1.31 mg/dL, n=317, p<0.01).
  • You keep total meal carbs under 40g. Light-carb radish meals averaged +24.8 mg/dL across 3,386 logs — the lowest carb bucket in the cohort.
Not for you if
  • You eat radish kimchi or banchan with rice. That pairing averaged +38.0 mg/dL across 152 logs — +10 mg/dL above radish alone (medium confidence), driven by the rice on the side.
  • You expect radish on a taco to keep the meal low-carb. The taco context averaged +33.5 mg/dL across 41 logs (low confidence) — the corn tortilla is the driver, not the radish.
  • You eat the French butter-on-baguette snack daily. That build averaged +29.7 mg/dL across 381 logs — +2 mg/dL above radish alone (medium confidence).
  • You stack radishes onto a 110g+ carb plate. Very-heavy-carb meals containing radish averaged +42.4 mg/dL — 71% above the light-carb baseline of +24.8 mg/dL.
● How it fits your day

Calorie band and pairings (member-measured)

Per serving
20–1,290 kcal
Ranges from a small radish-only side (~20 kcal) to a full radish-containing meal with bread or rice (~1,290 kcal); single-item logs averaged 87 kcal.
Pair before
  • Slice radishes thin onto a salad: that build averaged +27.1 mg/dL across 1,062 logs — a small discount vs. radish alone (high confidence).
  • Keep total meal carbs under 40g: light-carb radish meals averaged +24.8 mg/dL vs. +42.4 mg/dL in the 110g+ carb bucket — a 71% escalation.
Pair after
  • Time a 15–20 min walk after kimchi-banchan or taco meals containing radish — those averaged +38.0 mg/dL and +33.5 mg/dL respectively.
  • Favor morning timing when the menu allows: radish before 10 am averaged 11.3% below the rest-of-day baseline (n=317).
Avoid pairing
  • Avoid pairing radishes with kimchi-rice as a low-carb meal — the rice carrier pushed the average to +38 mg/dL across 152 logs (+10 mg/dL above alone).
  • Avoid stacking radish onto a 110g+ carb plate — that load drove the largest peak escalation in the cohort, reaching +42.4 mg/dL.
● 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 radish compares to other glucose-flat vegetables and the breads, tortillas, and rices that pair with it
Cucumber Glycemic Index & Glucose Score
Cucumber sits alongside radish in the GI 15 vegetable tier — both glucose-flat, both amplifiers of whatever carrier rides along.
Lettuce Glycemic Index & Glucose Score
Lettuce is the other low-GI salad-base vegetable — see how it behaves when stacked with the same dressings and toppings as radish.
Sauerkraut Glycemic Index & Glucose Score
Sauerkraut is the European fermented analogue to radish kimchi — explore how fermentation interacts with glucose response.
Baguette Glycemic Index & Glucose Score
The baguette under the French butter-and-radish snack is the actual spike driver — see what baguette does to glucose on its own.
White Rice Glycemic Index & Glucose Score
The rice served alongside radish banchan is the actual spike driver — see how rice behaves across the broader cohort.
Track Your Radish Response with Signos
See how your glucose reacts to radish on a salad vs. radish kimchi vs. the buttered-baguette snack — CGM data, personalized to you.

Frequently Asked Questions

Methodology

This page draws on 4,935 radish logs from 1,690 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 4,935 logs (median +24 mg/dL, IQR 23 mg/dL); a single-item subset of 69 logs (radishes eaten alone) averaged +26.0 mg/dL — small enough that we lean on the broader cohort for headline figures. 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 "radish", "radishes", or "daikon" as a primary ingredient. 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 — radish is calorically light but the bread, tortilla, or rice it travels with carries the carb load that varies most.
  • 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 single-item radish sub-cohort is very small (n=69) — radish is rarely logged as a standalone meal — so we rely on the broader 4,935-log cohort for headline statistics.
  • The watermelon-radish sub-cohort returned only n=22 matched logs and is rated fail-confidence; we omit it as an editorial driver.
  • The taco-garnish pairing slot is small (n=41, low confidence); the +6 mg/dL delta is directionally consistent with the corn-tortilla mechanism but the precise magnitude could shift.
  • The kimchi/banchan (n=152) and butter-on-baguette (n=381) pairing slots are both medium confidence; deltas are directionally robust but precise magnitudes could shift with larger samples.
  • 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 radish response

Across 4,935 logged radish meals from 1,690 members, the average glucose peak was +28.3 mg/dL — but radish itself is glucose-flat (GI 15, GL 0). The pairing does the work: salad context −1 mg/dL, butter-on-baguette +2 mg/dL, the taco garnish +6 mg/dL, kimchi-banchan +10 mg/dL. A CGM shows you exactly where you land and which builds work best for your biology.

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