Food Intelligence · Legume

Tofu Glycemic Index and Calculate Your Own Glucose Response

Across 15,450 logged tofu meals, Signos members averaged +32.9 mg/dL — but tofu itself has a glycemic index of 0. That cohort signal is the carb tofu sits next to: pad-thai builds ran +16 mg/dL above the plain-tofu baseline, curry-and-rice +10, stir-fry +6, miso soup +2. Tofu is a protein-vehicle story — the carb it rides on is the entire glucose response.

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

● Powered by Signos cohort dataHigh confidence · n=15,450
The swap calculator below draws on 15,450 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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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
11
of 100
Signos Glucose Score
Low Spike Risk
75% of members fall between +7 and +9 mg/dL
Predicted Curve · 3-hr window
1401001201401601800m30m60m90m120m150m180m+8
Peak
+8
mg/dL
Time in Range
100%
3hr window
Above 140
0m
danger zone
Swaps
0
applied
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● Key Findings · Does tofu spike blood sugar?

No — tofu alone is glycemically inert (GI=0, zero net carbs). The +32.9 mg/dL cohort average across 15,450 logs is driven entirely by the carb underneath the tofu. Tofu contributes essentially zero carbohydrate, which is why every form anchor in our recipe builder — firm/extra-firm, silken, fried, smoked/marinated — is set to 0 mg/dL. The cohort mean of +32.9 mg/dL exists because members log tofu alongside rice, noodles, curry sauce, and stir-fry vegetables. The pairing table makes the structure visible: pad-thai builds averaged +46.2 mg/dL (+16 mg/dL delta, n=386), curry-with-rice +40.7 mg/dL (+10, n=563), stir-fry over rice +35.9 mg/dL (+6, n=562), miso soup +32.4 mg/dL (+2, n=507), Asian sesame salad +31.5 mg/dL (+1, n=1,703). At the meal level, ≥60g total carbs drove a 59.7% peak increase across 3,329 matched logs (p<0.001) — the single largest effect measured. Tofu is a protein-vehicle; whatever it sits next to is the actual glucose driver.

  • Pad-thai pairings drove the highest spikes: +46.2 mg/dL average, a +16 mg/dL delta over plain tofu across 386 matched logs (medium confidence).
  • Curry-and-rice builds added +10 mg/dL: tofu curry meals averaged +40.7 mg/dL vs. +30.2 mg/dL plain-tofu baseline (n=563, high confidence).
  • Asian sesame salad and miso soup pairings barely moved the curve: +1 to +2 mg/dL above plain tofu across 2,210 matched logs.
  • Morning timing cut peaks 22%: tofu meals logged at breakfast averaged +26.7 mg/dL vs. +34.4 mg/dL at dinner (n=2,223 vs. n=6,284).
● Signos Rules

Three citable insights from this recipe's data

Rule 1
"The Carb-Vehicle Effect"
+16 mg/dL on pad thai
Tofu has no glycemic signal of its own — published GI is 0 and the recipe-builder anchor is 0. The entire +32.9 mg/dL cohort mean reflects the carb tofu rides on. Pad-thai pairings averaged +46.2 mg/dL (n=386) — a +16 mg/dL delta over plain tofu. Curry with rice +10, stir-fry +6, miso soup +2, sesame salad +1. Every degree of spike comes from the noodle, the rice, or the sauce — not the soybean curd.
Rule 2
"Form Doesn't Matter"
0 mg/dL across all four forms
Firm, silken, fried/agedashi, and smoked/marinated — none of them contain digestible carbs, so all four form anchors sit at 0 mg/dL in the recipe builder. The cohort means (silken +32.0, smoked +30.1, firm +30.0, fried +37.7) reflect what members ate alongside each form, not the tofu itself. Fried tofu trends highest because it's most often logged in noodle bowls; smoked/marinated runs lowest because it's most often a snack.
Rule 3
"The Carb-Load Penalty"
+59.7% peak
When tofu appears in a meal carrying ≥60g of total carbs, the average glucose peak jumps 59.7% vs. the low-carb baseline (CI: +15.52 to +17.19 mg/dL, n=3,329 vs. n=8,729, p<0.001). The effect is cumulative — at 110g+ carbs, peaks reach +47.7 mg/dL vs. +27.4 mg/dL in the 0–40g bucket. Keeping total meal carbs under 40g is the single most impactful lever in the dataset for tofu.
● Curious about your own?

Curious how your body responds to tofu specifically?

Tofu has a glycemic index of 0 — but the carb it rides on isn't 0. Across 15,450 logged tofu meals, the average peak landed at +32.9 mg/dL, with pad-thai builds hitting +46.2 and miso-soup pairings barely moving from baseline. Your own response depends entirely on what's underneath. A CGM tells you which builds work for your biology.

Learn how Signos works
Why this meal spikes

This meal stacks 3 independent spike drivers — together they account for +0 mg/dL.

Driver 1
The carb underneath (rice, noodles, curry sauce)
+16 mg/dL
The dominant — really, the only — driver. Pad-thai pairings ran +16 mg/dL above plain tofu (n=386); curry +10 (n=563); stir-fry +6 (n=562). Tofu contributes zero carbs to any of these meals.
Driver 2
Total meal carb load (≥60g) when tofu is present
+16 mg/dL
Meals tagged with tofu and ≥60g total carbs ran 59.7% higher than the lower-carb baseline (CI: +15.52 to +17.19 mg/dL, n=3,329 vs. n=8,729, p<0.001). Same effect, expressed at meal level: the carbs are doing the work.
Driver 3
Sugar load (≥20g) in the surrounding meal
+12 mg/dL
High-sugar pairings (≥20g) lifted peaks 40.4% (CI: +11.14 to +13.24 mg/dL, n=1,966 vs. n=9,767, p<0.001). Sweet-and-sour sauce, teriyaki glaze, and pad-thai tamarind-sugar dressing all drive this signal — tofu is along for the ride.
● Which bucket are you in?

Some members spike +27.4 mg/dL. Others spike +47.7. 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 tofu is how cleanly the carb-vehicle pattern showed up across 15,450 logs. Tofu has a glycemic index of 0 — it cannot raise blood sugar on its own — yet the cohort mean came in at +32.9 mg/dL. Every point of that signal is the carb the tofu is paired with: pad thai +16, curry-and-rice +10, stir-fry +6, miso soup +2, sesame salad +1. Our recipe-builder form anchors are all set to 0, which means firm, silken, fried, and smoked all read identically at the alone-anchor — exactly as the published GI predicts. Tofu is a protein-vehicle, not a glucose driver.
Signos Data Science Team

Why this happens, physiologically

Tofu contributes essentially zero glucose; the cohort mean of +32.9 mg/dL across 15,450 logs reflects the carb underneath, not the soy protein. Firm tofu carries only about 1–2g net carbs per 100g, which is why the published GI is 0 and our recipe-builder form anchors are overridden to 0 mg/dL. The headline story is the pairing slot: pad thai averaged +46.2 mg/dL (+16 mg/dL delta), curry-with-rice +40.7 (+10), stir-fry +35.9 (+6), miso soup +32.4 (+2), sesame salad +31.5 (+1). Plain tofu cubes anchored at +30.2 mg/dL across 10,200 baseline logs — almost certainly reflecting trace co-logged items rather than the tofu itself. Morning timing layers on a secondary effect: breakfast tofu meals averaged +26.7 mg/dL vs. +34.4 mg/dL at dinner (n=2,223 vs. n=6,284), a 22% gap consistent with diurnal insulin sensitivity. These are observational patterns, not causal claims.

● Three mechanisms explain tofu's glucose range

Zero-carb anchor, carb-vehicle reality, and meal-timing each shape what shows up on the trace

  1. Mechanism 1
    GI = 0
    Zero-carb anchor
    Tofu contains essentially no carbohydrate, which is why the published glycemic index is 0 and every form anchor in our recipe builder is set to 0 mg/dL. Pure tofu cannot raise glucose because there is no substrate to digest into sugar.
  2. Mechanism 2
    +16 mg/dL
    Carb-vehicle reality
    Members rarely eat tofu alone — it sits in pad thai, curry, stir-fry, or miso soup. The pairing table shows the entire glucose response in those builds comes from the carb: pad thai +16 mg/dL above plain-tofu baseline (n=386), curry +10 (n=563), stir-fry +6 (n=562).
  3. Mechanism 3
    −22%
    Morning timing
    Breakfast tofu meals averaged +26.7 mg/dL vs. +34.4 mg/dL at dinner (n=2,223 vs. n=6,284) — a 22% reduction consistent with morning insulin sensitivity advantages across the broader cohort. Observational, not yet established as causal.
● Fit Check
Tofu is a glycemically inert protein — what it rides on is the entire story.
This is for you if
  • You eat tofu in an Asian sesame salad or miso soup. Those pairings averaged +31.5 and +32.4 mg/dL — only +1 to +2 mg/dL above plain tofu across 2,210 matched logs.
  • You keep total meal carbs under 40g. Light-carb tofu meals averaged just +27.4 mg/dL — a 43% lower peak than very-heavy builds (+47.7 mg/dL, n=613).
  • You eat tofu at breakfast. Morning logs averaged +26.7 mg/dL vs. +34.4 mg/dL at dinner — a 22% reduction across 2,223 morning meals.
  • You reach for smoked, marinated, silken, firm, or fried tofu — they all anchor at 0 mg/dL. The form itself doesn't change the glucose response.
Not for you if
  • You order tofu in pad thai or rice noodles. That pairing averaged +46.2 mg/dL — a +16 mg/dL delta, the largest in the pairing table (n=386, medium confidence).
  • You eat tofu in Thai or Indian curry with rice. Curry pairings averaged +40.7 mg/dL, +10 mg/dL above plain tofu across 563 matched logs.
  • Your tofu meal exceeds 110g of total carbs. Very-heavy carb builds averaged +47.7 mg/dL — a 74% jump from light-carb meals (+27.4 mg/dL) across 613 logs.
  • Your sauce is high-sugar (≥20g). The high-sugar modifier raised peaks 40.4% (CI: +11.14 to +13.24 mg/dL, n=1,966, p<0.001) — sweet-and-sour and teriyaki glazes are the usual culprits.
● How it fits your day

Calorie band and pairings (member-measured)

Per serving
351–1,124 kcal
Light tofu meals (0–40g carbs) average 351 kcal; very-heavy carb builds (110g+ carbs) average 1,124 kcal. Noodle and rice pairings drive most of the upper-end calorie load.
Pair before
  • Keep total meal carbs under 40g: light-carb builds averaged +27.4 mg/dL vs. +47.7 mg/dL for very heavy (110g+) carb loads — a 43% reduction across 8,729 vs. 613 logs.
  • Choose a sesame-salad or miso-soup build over a noodle bowl: those pairings averaged only +1 to +2 mg/dL above plain tofu in 2,210 matched logs.
Pair after
  • A 10–15 min walk after a pad-thai or curry-with-rice meal helps clear circulating glucose — relevant given those builds averaged +46.2 and +40.7 mg/dL respectively.
  • Note that morning tofu logs (before 10am) ran 23.4% lower than later-day meals (CI: −8.9 to −7.0 mg/dL, n=1,573) — earlier insulin sensitivity helps.
Avoid pairing
  • Avoid pad-thai tofu builds with sweet tamarind sauce: that pairing averaged +46.2 mg/dL, the highest in the dataset (+16 mg/dL delta).
  • Avoid stacking sweet sauces on a tofu-and-rice plate (≥20g sugar): the high-sugar modifier drove a 40.4% spike increase (+11–13 mg/dL, p<0.001) across 1,966 matched logs.
● 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 tofu compares to other proteins and legumes in glucose response

Frequently Asked Questions

Methodology

This page is grounded in Signos CGM data collected between March 2025 and April 2026, covering 15,450 tofu-tagged logged meals from 3,303 unique members (the broader cohort that powers the modifier and pairing analysis), with a single-item sub-cohort of 898 meals (521 members) where tofu was logged alone. Because tofu has a published glycemic index of 0 and glycemic load of 0, the recipe-builder form anchors are overridden to 0 mg/dL — the underlying cohort means (preserved in `option_mean_full_cohort`) reflect the carbs members ate alongside each form, not the tofu itself. Modifier effects were estimated using Welch's t-test on matched pairs; all reported effects carry p<0.001 unless noted. Only meals with a measured glucose rise between 0 and 100 mg/dL were included (ppgr_case='regular'). The reported broader-cohort mean is +32.9 mg/dL; the single-item mean is +28.1 mg/dL — the gap reflects the carb context that typically accompanies tofu in real meals. A minimum of 30 matched meals is required for any pairing slot to appear in the recipe builder.

Limitations

  • Self-reported portion sizes introduce measurement noise; logged "tofu" may reflect anywhere from 50g to 300g in practice, which affects pairing-level peak estimates.
  • Cohort means appear non-zero (e.g. firm tofu +30.0 mg/dL) because members underreport sides — "logged: tofu; ate: tofu over rice." The published GI=0 is the editorially correct anchor, which is why our recipe builder reads alone = 0.
  • Cohort skews health-motivated; Signos members actively tracking glucose tend to eat more mindfully than the general population, so real-world average pairings may differ.
  • The pad-thai sub-cohort (n=386) is medium-confidence; the +16 mg/dL delta is directionally consistent with other noodle pairings but absolute estimates carry wider uncertainty.
  • The smoked/marinated form sub-cohort (n=363) is medium-confidence; cohort-mean differences across forms reflect pairing context, not the tofu protein itself.
  • All modifier effects are observational. Matched-pair design reduces but does not eliminate confounding from unmeasured variables such as stress, sleep quality, or prior physical activity.
● Get your own data

See your own tofu response

Tofu alone is glycemically inert (GI=0), but the cohort signal of +32.9 mg/dL across 15,450 logs reflects the rice, noodles, and curry sauces underneath. Pad-thai pairings ran +16 mg/dL over plain tofu; curry-with-rice +10; stir-fry +6. Your personal response depends on the carb pairing — and on your insulin sensitivity, microbiome, and stress. A CGM shows you exactly where each build lands.

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