● Food Intelligence · Vegetable

Spinach Glycemic Index and Calculate Your Own Glucose Response

Across 64,980 spinach-containing meals, members averaged +27.3 mg/dL — a number that says almost nothing about the leaves themselves. Spinach has a published GI of 15 and a glycemic load of 0; the cohort signal traces almost entirely to the wrap (+9 mg/dL), rice bowl (+11 mg/dL), or pasta (+8 mg/dL) it's eaten with.

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

● Powered by Signos cohort dataHigh confidence · n=64,980
The swap calculator below draws on 64,980 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.

Ingredients — Tap to Swap
Meal Context
Pre-meal sequence
Activity after meal
Time of day
36
of 100
Signos Glucose Score
Moderate Spike Risk
75% of members fall between +22 and +32 mg/dL
Predicted Curve · 3-hr window
1401001201401601800m30m60m90m120m150m180m+27
Peak
+27
mg/dL
Time in Range
100%
3hr window
Above 140
0m
danger zone
Swaps
0
applied
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● Key Findings · Does spinach spike blood sugar?

Barely — spinach itself has a GI of 15 and GL of 0, and the +27.3 mg/dL cohort mean across 64,980 logs is driven almost entirely by what's served with the leaves. Spinach is the lowest-glycemic vegetable in the atlas, and across 64,980 spinach-containing meals from 11,751 unique members, the median glucose peak was just +23 mg/dL with 42.5% of responses landing in the low-spike range. The numbers move when carbs enter the picture: a wrap or quesadilla pushes the peak to +34.8 mg/dL (+9 mg/dL above the spinach-alone baseline), a rice bowl reaches +36.4 mg/dL (+11 mg/dL), and pasta lands at +33.8 mg/dL (+8 mg/dL). A spinach smoothie, by contrast, adds just +1 mg/dL — observational, not yet causal.

  • ▸The carb-load effect dwarfs every other modifier: meals with ≥60g of carbs alongside spinach run 60.5% higher than the low-carb baseline (n=7,564 vs n=46,389, p<0.001).
  • ▸Rice and grain bowls drive the largest single carb-pairing penalty: spinach in a rice bowl averages +36.4 mg/dL vs +25.5 mg/dL alone — a +11 mg/dL jump across 3,417 logs.
  • ▸Morning timing meaningfully lowers the spike: spinach-containing meals logged before 10 am averaged 19.6% lower peaks than the rest of the day (CI: −6.06 to −5.45 mg/dL, n=17,361, p<0.001).
  • ▸Baby spinach reads slightly cleaner than fresh/raw on the slot anchor: +23.8 mg/dL vs +26.1 mg/dL across 13,671 baby-spinach logs (delta −2.3 mg/dL, high confidence).
● Signos Rules

Three citable insights from this recipe's data

Rule 1
"The Carb-Load Penalty"
+60.5% peak
When spinach appears in a meal with ≥60g of carbs, the glucose peak runs 60.5% above the low-carb baseline (n=7,564, p<0.001). Spinach itself is GI=15 with a glycemic load of 0 — every point of that 60.5% comes from the bread, rice, or pasta on the plate. Rice/grain bowls (+11 mg/dL) and wraps (+9 mg/dL) are the heaviest pairings in the modifier table.
Rule 2
"The Morning Edge"
−19.6% peak
Spinach-containing meals logged before 10 am average 19.6% lower glucose peaks than the same food logged later in the day (n=17,361 morning logs vs. n=37,531 non-morning, p<0.001). Breakfast meals with spinach averaged +24.0 mg/dL — the lowest of any meal-time slot — compared to +30.3 mg/dL at dinner. Earlier insulin sensitivity likely drives the gap, though the effect is observational.
Rule 3
"The Smoothie Pass"
+1 mg/dL vs. alone
Adding spinach to a smoothie or green juice barely moves the peak: +26.2 mg/dL versus +25.5 mg/dL for spinach alone (n=543, high confidence). That's well below the +9 to +11 mg/dL penalty for wraps and rice bowls. The smoothie's typical ingredient mix — fruit, yogurt, nut butter — drives most of any spike that does occur, and the spinach itself contributes almost none of it.
● Curious about your own?

Curious how your body responds to spinach specifically?

Across 64,980 logged meals where members ate spinach in some form, the average glucose peak was +27.3 mg/dL — but the IQR spans 22 mg/dL (p25: +14, p75: +37), 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.

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Why this meal spikes

This meal stacks 3 independent spike drivers — together they account for +26 mg/dL.

Driver 1
Meal-level carbohydrates (≥60g when paired)
+14.6 mg/dL
The dominant lever: meals with ≥60g carbs ran 60.5% higher than low-carb logs (p<0.001, n=7,564 vs n=46,389). Spinach itself is GI=15 with a glycemic load of 0, so this effect is entirely from what it's eaten with.
Driver 2
High-sugar pairings (≥20g sugar)
+10.1 mg/dL
Meals containing ≥20g sugar alongside spinach spiked 39.8% higher than the low-sugar baseline (n=7,088, CI: 9.59 to 10.56 mg/dL, p<0.001). Smoothies, juices, and sweetened sides drive most of this effect.
Driver 3
Individual glucose variability (IQR 22 mg/dL)
+11 mg/dL
The interquartile range spans 22 mg/dL (p25: +14, p75: +37 mg/dL), meaning personal metabolic state — insulin sensitivity, microbiome, sleep, stress — accounts for a substantial portion of any single reading.
● Which bucket are you in?

Some members spike +24.1 mg/dL. Others spike +42.3. 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 spinach is how cleanly the data separated the leaves from everything around them. Spinach has a published GI of 15 and GL of 0 — basically a glucose passenger. But the cohort mean of +27.3 mg/dL across 64,980 meals tells a different-sounding story until you split it: spinach in a rice bowl runs +36.4 mg/dL, in a wrap +34.8, and in a smoothie just +26.2. The leaves don't do the work; the rice, tortilla, or banana underneath does. Spinach is the cleanest example we have of a food whose published GI and cohort behavior agree — once you control for the carbs around it.
— Signos Data Science Team

Why this happens, physiologically

Spinach has a published glycemic index of 15 and a glycemic load of 0 — a 30g serving contains roughly 1g of net carbs alongside ~0.7g of fiber. The +27.3 mg/dL cohort mean across 64,980 logs is therefore not a measurement of the spinach itself; it's a measurement of the meals spinach tends to live in. The cohort data confirms this directly: meals with ≥60g of carbs alongside spinach ran 60.5% higher than the low-carb baseline (p<0.001, n=7,564), and the carb-bucket analysis shows a near-linear escalation from +24.1 mg/dL in light (0–40g carb) meals all the way to +42.3 mg/dL in very-heavy (110g+) meals — a 75.5% jump. Two secondary levers pull in the opposite direction: high protein pairings (≥15g) trimmed the response by ~7.5% and high-fat pairings (≥15g) by ~4.6%, both highly significant. The mechanism is observational, not yet causal, but the pattern is consistent with protein and fat slowing gastric emptying and blunting the glycemic excursion from any co-ingested carbs.

● Three mechanisms explain spinach's glucose range

Meal carb load, time of day, and protein co-ingestion each drive measurable shifts in spinach's glucose response

  1. Mechanism 1
    +60.5%
    High carb co-load
    Meals logged with ≥60g total carbs showed peaks 60.5% above the low-carb baseline (n=7,564, p<0.001). Spinach itself contributes near-zero digestible carbs — every point of that 60.5% comes from what it's eaten with.
  2. Mechanism 2
    −19.6%
    Morning timing
    Spinach-containing meals before 10 am ran 19.6% lower than later-in-day logs (n=17,361, CI: −6.06 to −5.45 mg/dL, p<0.001). Earlier insulin sensitivity likely drives the gap, consistent with the broader chronobiology literature on first-meal-of-the-day responses.
  3. Mechanism 3
    −7.5%
    Protein co-ingestion
    Protein pairings ≥15g cut the response by ~7.5% (n=55,002 vs 4,307, p<0.001). The mechanism is delayed gastric emptying — a spinach omelette runs cleaner than a spinach wrap by a measurable margin.
● Fit Check
Spinach is the lowest-glycemic vegetable in the atlas — a food whose own glucose impact is essentially zero, until what's served with it changes the math.
✓ This is for you if
  • ▸You eat spinach as a salad base or in eggs. Spinach alone averaged +25.5 mg/dL, and 42.5% of all spinach logs landed in the low-spike range.
  • ▸You blend spinach into smoothies. That pairing added just +1 mg/dL over the spinach-alone baseline across 543 logs — the cleanest carb pairing measured.
  • ▸You keep total meal carbs under 40g. Light-carb spinach meals averaged just +24.1 mg/dL — the lowest carb bucket in the cohort (n=46,389).
  • ▸You reach for baby spinach. Baby spinach averaged +23.8 mg/dL vs. +26.1 mg/dL for fresh/raw — a meaningful −2.3 mg/dL edge across 13,671 logs.
✗ Not for you if
  • ▸You build spinach into a wrap, tortilla, or quesadilla. That pairing added +9 mg/dL over the spinach-alone baseline across 4,200 logs.
  • ▸You serve spinach over a rice or grain bowl. That combination averaged +36.4 mg/dL — a +11 mg/dL delta over the spinach-alone baseline (n=3,417).
  • ▸You expect creamed spinach to behave like fresh. Creamed spinach averaged +28.3 mg/dL — +2.2 mg/dL above the fresh anchor across 536 logs.
  • ▸You pair spinach with pasta dishes. Spinach-with-pasta averaged +33.8 mg/dL across 1,822 logs — a +8 mg/dL pairing penalty.
● How it fits your day

Calorie band and pairings (member-measured)

Per serving
10–520 kcal
Ranges from a 30g raw spinach side (~7 kcal) to a full spinach-and-pasta plate (~520 kcal); single-item logs averaged 310 kcal.
● Pair before
  • ▸Pair spinach with eggs or another high-protein anchor: protein ≥15g cut peaks 7.5% (n=55,002, p<0.001).
  • ▸Keep total meal carbs under 40g: light-carb spinach meals averaged +24.1 mg/dL vs. +42.3 mg/dL in the 110g+ carb bucket — a 75.5% escalation.
● Pair after
  • ▸Time a 15–20 min walk after high-carb spinach meals (e.g. spinach pasta or rice bowls), which averaged +33.8 to +36.4 mg/dL — the highest pairing spikes in the cohort.
  • ▸If dinner is spinach-heavy, note that breakfast spinach logs averaged +24.0 mg/dL vs. dinner at +30.3 mg/dL — favor morning timing when possible.
● Avoid pairing
  • ▸Avoid spinach in a wrap, tortilla, or quesadilla as a primary lunch: that pairing added +9 mg/dL over baseline (treatment mean +34.8 mg/dL, n=4,200).
  • ▸Avoid stacking spinach onto rice/grain bowls without a protein anchor — that combination averaged +36.4 mg/dL versus +25.5 mg/dL alone (n=3,417).
● 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 spinach's glucose response compares to other low-glycemic vegetables and the proteins it pairs with
Kale Glycemic Index & Glucose Score
Kale, like spinach, is a near-zero-carb leafy green — see how the cohort response compares head-to-head across the salad-bowl context.
Lettuce Glycemic Index & Glucose Score
Lettuce is the other major salad base in the atlas — useful for understanding how the leaves vs. dressings split applies across greens.
Broccoli Glycemic Index & Glucose Score
Broccoli is the other low-GI vegetable cohort — a comparison point for how cooked vs. raw cruciferous greens behave alongside carbs.
Cucumber Glycemic Index & Glucose Score
Cucumber sits in the same near-zero-GL band as spinach — useful for benchmarking what 'noise-floor' vegetable response looks like.
Eggs Glycemic Index & Glucose Score
A spinach omelette is one of the cleanest spinach pairings — see how eggs behave on their own and why protein anchors lower the meal-level peak.
Track Your Spinach Response with Signos →
See how your glucose reacts to spinach in a salad vs. a wrap vs. a smoothie — CGM data, personalized to you.

Frequently Asked Questions

Methodology

This page draws on 64,980 spinach-containing logs from 11,751 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 +23 mg/dL is a few mg/dL lower than the mean of +27.3 mg/dL, which is typical for this type of data. The food was identified in member logs using a regex matching "spinach" as a primary ingredient, excluding compound dishes (spinach dip, spinach pie, spinach lasagna, spinach ravioli, spinach quiche) where spinach was a minor or labeled-out component. Any carb-pair pairing slot requires at least 100 matched meals before it appears in the recipe builder.

Limitations

  • Self-reported portion sizes introduce measurement error — a logged "handful" of spinach 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 salad-with-bread/croutons sub-cohort is small (n=220) and carries medium confidence — its reported delta of +3 mg/dL versus spinach alone should be treated as directional only.
  • The sautéed and frozen sub-cohorts are small (n=130 and n=270 in the recipe-form slot); their −1 to −2 mg/dL deltas vs. fresh are directional pending larger samples.
  • Modifier analyses reflect meal-level correlations, not controlled feeding trials — causality cannot be established from observational CGM data alone.
  • Because spinach's own glycemic load is 0, all carb-pair deltas are functionally measurements of the paired carb (rice, tortilla, pasta) — not of the spinach itself.
● Get your own data

See your own spinach response

Across 64,980 logged meals containing spinach, the average glucose peak was +27.3 mg/dL — but the IQR spans 22 mg/dL, meaning your personal response could land well above or below that. What you pair with spinach matters too: a rice bowl adds +11 mg/dL, while a smoothie adds just +1 mg/dL. A CGM shows you exactly where you land and which builds work best for your biology.

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