Bread vs pasta: pasta sits lower on blood sugar, bread carries the salt

In a meta-analysis of 32 randomized comparisons in 2,448 adults, low glycemic index diets that included pasta reduced body weight by 1.4 lb (95% CI -1.9 to -0.93; metric: 0.63 kg, -0.84 to -0.42) against higher glycemic index diets, with moderate certainty. The same search found no trial that tested pasta on its own, so that 1.4 lb (0.63 kg) belongs to the whole diet. On blood sugar the two foods do differ. A systematic review with meta-analysis found pasta meals gave a lower glucose response after eating than bread or potato meals. Its abstract does not give the size, these were short tests after single meals, and it found no long-term evidence on heart or metabolic disease. International glycemic index tables list pasta as usually low, at 55 or below, while breads come in high, medium and low versions depending on how they are made. Another everyday difference is salt. White bread averaged 420 mg sodium per 3.5 oz (100 g) across 6 USDA samples (range 264 to 516), and dry spaghetti about 2 mg, a figure that leaves out salt added to the cooking water.

How much is actually in it

• International glycemic index tables list pasta as usually low GI, while breads come in high, medium and low GI versions depending on how they are made. — Over 4,000 GI test values from published and unpublished sources worldwide (n = 4000+ items) Evidence C source
  Pasta usually GI 55 or less; bread GI varies widely by manufacture
• In USDA Foundation samples, white bread averaged 420 mg sodium per 3.5 oz (100 g) while dry enriched spaghetti had about 2 mg. — USDA Foundation Foods: Bread, white, commercial (6 samples); Pasta, dry, enriched, spaghetti (7 samples) (n = 6 and 7 samples) Evidence E source
  Sodium: bread 419.7 mg/100 g (range 264-516); dry spaghetti 2.4 mg/100 g (range 0-4.84)

What a real portion looks like

• In the US dietary survey a regular slice of white bread weighs 0.99 oz (28 g) and a cup of cooked pasta 140 g. — FNDDS portion weights for Bread, white (51101000) and Pasta, cooked (56130000) (n = -) Evidence E source
  1 medium slice white bread 28 g; 1 cup cooked pasta 140 g; 1 oz dry pasta yields 80 g cooked
• The 2025-2030 US Dietary Guidelines set a whole grains goal of 2 to 4 servings a day, adjusted to individual calorie needs, without defining the serving size. — United States general population, Dietary Guidelines for Americans 2025-2030 Evidence E source
  2–4 servings of whole grains per day

What your body absorbs

• In a randomized crossover trial, plain spaghetti had a GI of 44 versus 63 for plain rice. — Healthy adults eating spaghetti or rice plain, with tomato sauce and olive oil, or with pesto (n = -) Evidence B source
  GI spaghetti 44 +/- 7 vs rice 63 +/- 3 (p = 0.003)
• In short-term human studies, low-phytate white bread raised serum iron more in 2 hours than high-phytate whole wheat bread (59 vs 30 ug per 3.4 fl oz (100 mL)). — 8 human intervention studies in healthy or iron-deficient participants (n = 8 studies) Evidence C source
  2 h serum iron rise 59 vs 30 ug Fe/100 mL; long-term trials showed no gain in ferritin

What cooking and storage change

• For pasta boiled and drained, USDA retention factors give 65% thiamin, 70% folate and 75% iron retained. — USDA R6 group Cereal Grains and Pasta, PASTA,BOILED,DRAINED (n = -) Evidence E source
  Thiamin 65%, niacin 65%, folate 70%, iron 75%, riboflavin 75%, potassium 30% retained

What it does to your health

• Observational data from 17 cohorts with over 875,000 people found refined grain intake not associated with cardiovascular disease (HR 1.08, 95% CI 0.99 to 1.18). — >875,000 participants in 17 prospective cohort studies (n = 875000) Evidence C source
  CVD HR 1.08 (95% CI 0.99 to 1.18), I2 = 70%
• Observational data link each extra 30 g a day of whole grains with a 6% lower risk of coronary heart disease (RR 0.94). — 1,624,407 participants in 68 prospective cohort studies (n = 1624407) Evidence C source
  Per 30 g/day whole grain: CHD RR 0.94 (0.92 to 0.97), CVD RR 0.92 (0.88 to 0.96), all-cause mortality RR 0.94 (0.92 to 0.97)
• The 2025-2030 US Dietary Guidelines tell Americans to prioritize fiber-rich whole grains and significantly reduce highly processed refined carbohydrates, naming white bread, flour tortillas and crackers. Pasta is not named. — United States general population, Dietary Guidelines for Americans 2025-2030 Evidence E source
  Federal advice to significantly reduce refined carbohydrates, white bread named

Safety, limits and interactions

• A meta-analysis of bread contamination studies found benzo[a]pyrene above permitted limits in 26.47% of the studies and PAH4 in 20.28%. — 1,057 bread samples from 34 studies worldwide (n = 1057 samples) Evidence C source
  BaP above limit in 26.47% of studies, PAH4 in 20.28% (share of studies, not of loaves)
• Since 1998 the FDA has required 140 mcg folic acid per 3.5 oz (100 g) in enriched breads and pastas to reduce neural tube defects. — US enriched grain products (n = -) Evidence E source
  140 mcg folic acid/100 g mandatory in enriched grains since January 1998

What people believe that the data does not support

• In a meta-analysis of 32 randomized trial comparisons in 2,448 adults, pasta within low-glycemic-index diets reduced body weight by 1.4 lb (0.63 kg) versus higher-GI diets. — 2,448 adults in 32 RCT comparisons of at least 3 weeks, pasta within low-GI dietary patterns (n = 2448) Evidence A source
  Body weight MD -1.4 lb (95% CI -1.9 to -0.93; metric: -0.63 kg, -0.84 to -0.42); BMI MD -0.26 kg/m2 (95% CI -0.36 to -0.16)
• In a 16-week RCT in 194 adults at risk of type 2 diabetes, oat beta-glucan bread did not lower HbA1c compared with whole-grain wheat bread (difference -0.01%). — 194 adults aged 58 +/- 8, BMI 32, at risk of type 2 diabetes, at least 3 slices a day, 16 weeks, Germany, Norway, Sweden (n = 194) Evidence B source
  HbA1c difference -0.01% (95% CI -0.03 to 0.06); LDL -4.3 mg/dL (95% CI -10 to 1.9; metric: -0.11 mmol/L, -0.27 to 0.05)
• The EU did not authorize a claim that the carbohydrates in pasta give a low and slow blood sugar response. — EU health claims register (n = -) Evidence E source
  Claim status: non-authorized
• The EU did not authorize a claim that high-fiber sourdough rye bread reduces blood sugar after meals. — EU health claims register (n = -) Evidence E source
  Claim status: non-authorized
• FDA names fortified white bread among products that could be labeled “healthy” under the old rule but no longer can under the rule updated in December 2024. — US food labeling: the voluntary “healthy” nutrient content claim, 21 CFR 101.65(d) as updated by FDA Evidence E source
  Fortified white bread named as no longer eligible under the updated criteria

Who this works differently for

• In a crossover RCT in 30 Chinese and Indian adults, semolina spaghetti had a GI of 53 versus 80 for white rice and 74 for wheat noodles. — 30 healthy Chinese and Indian adults (17 men, 13 women), single test meals, crossover (n = 30) Evidence B source
  GI semolina spaghetti 53, wholegrain spaghetti 54, mee pok noodles 74, white rice 80
• In a crossover RCT in 13 healthy adults, gluten-free rice and corn pasta raised blood glucose 57% higher at 30 minutes than wheat pasta. — 13 healthy adults, macaroni and cheese with wheat pasta or three gluten-free pastas, 4x4 crossover (n = 13) Evidence B source
  Plasma glucose at 30 min 57% higher for rice and corn GF pasta vs wheat pasta (p = 0.011)
• In 46 midlife New Zealand women eating on average 1.6 slices of iodine-fortified bread a day, median urinary iodine was 49 ug/L, indicating iodine deficiency. — 46 women aged 40-63 in Auckland eating 1.6 slices of fortified bread a day on average (n = 46) Evidence C source
  Median urinary iodine 49 ug/L; 32% plasma selenium below 110 ug/L

What is still unknown

• The same meta-analysis found no randomized trial that tested pasta on its own, so any weight effect belongs to the whole low-GI diet. — Search of MEDLINE, Embase, CINAHL and Cochrane through February 2017 (n = 0 trials of pasta alone) Evidence A source
  0 trial comparisons of pasta alone; 32 of pasta within low-GI diets
• A systematic review with meta-analysis found pasta meals raise blood glucose less after eating than bread or potato meals, but long-term evidence on pasta versus bread is lacking. — Postprandial studies comparing pasta with bread or potato meals, plus cohorts and trials on cardio-metabolic risk (n = -) Evidence C source
  Lower postprandial glucose after pasta vs bread or potato (standardized mean difference, size not in abstract)

The bottom line

A regular slice of white bread weighs 0.99 oz (28 g) and a cup of cooked pasta 140 g in the US dietary survey. Head to head tests keep putting pasta low. In 30 healthy Chinese and Indian adults of normal weight eating single test meals, semolina spaghetti had a glycemic index of 53 and wholegrain spaghetti 54, against 74 for wheat noodles and 80 for white rice. In another crossover trial plain spaghetti scored 44 against 63 for plain rice, and that abstract does not say how many people took part. Gluten-free pasta behaves differently. In 13 healthy adults eating macaroni and cheese, rice and corn pasta gave blood glucose 57% higher at 30 minutes than wheat pasta, in one small trial with one dish. Swapping one bread for another made no measurable difference in the one long trial we have. Over 16 weeks in 194 adults at risk of type 2 diabetes, oat beta-glucan bread gave no significant change in HbA1c against whole-grain wheat bread (difference -0.01%, 95% CI -0.03 to 0.06), and white bread was never the comparison. The EU refused a claim that pasta gives a low and slow blood sugar response, and another that high-fiber sourdough rye bread lowers blood sugar after meals, meaning the evidence was judged insufficient. In December 2024 the FDA named fortified white bread among foods that qualified for the voluntary “healthy” label under the old rule and no longer do under the updated one. The 2025-2030 US Dietary Guidelines tell Americans to significantly reduce highly processed refined carbohydrates and name white bread among them. Pasta appears neither in that list nor among whole grains, so the advice does not say where a plate of white spaghetti falls. The same guidelines set a goal of 2 to 4 whole grain servings a day and do not define how big a serving is. Observational data from 17 cohorts with over 875,000 people found refined grain intake not associated with cardiovascular disease (HR 1.08, 95% CI 0.99 to 1.18), and unmeasured confounding is possible. Cohort data on whole grains link each extra 30 g a day with a 6% lower risk of coronary heart disease (RR 0.94, 95% CI 0.92 to 0.97), an association from observation. In short tests, low-phytate white bread raised serum iron more in two hours than high-phytate whole wheat bread, 59 against 30 micrograms per 3.4 fl oz (100 mL). Most of those studies carried a high risk of bias, and longer trials showed no gain in iron stores. Boiling and draining pasta keeps 65% of thiamin, 70% of folate and 75% of iron by USDA group factors from 1975. On safety, a meta-analysis of 1,057 bread samples from 34 studies, mostly of traditional breads in a few countries, found benzo[a]pyrene above permitted limits in 26.47% of the studies. That is a share of studies, and it says nothing about the share of loaves on a shelf. For pregnancy, US law has required 140 mcg folic acid per 3.5 oz (100 g) in enriched breads and pastas since 1998 to cut neural tube defects, and the EU has no such rule. In 46 self-selected Auckland women aged 40 to 63 eating on average 1.6 slices of iodine-fortified bread a day, median urinary iodine was 49 micrograms per liter, which the authors read as deficiency. New Zealand fortifies its bread with iodine, so the result does not carry over to countries without that rule. We found no card on celiac disease or on interactions with medicines.

Sources

1. brpa-daily-r5-04 · systematic review of GI data
   Dairy products, legumes, pasta, and fruits were usually low-GI foods (≤55 on the 100-point glucose scale) and had consistent values around the world. Cereals and cereal products, however, including whole-grain or whole-meal versions, showed wide variation in GI values, presumably arising from variations in manufacturing methods. Breads, breakfast cereals, rice, savory snack products, and regional foods were available in high-, medium-, and low-GI versions.
   Am J Clin Nutr, 2021 · checked 2026-09-28
2. brpa-daily-r5-17 · food composition data
   Bread, white, commercial: Sodium, Na 419.7 MG, range 264.0-516.0 (median 428.0), samples 6 · Pasta, dry, enriched, spaghetti: Sodium, Na 2.406 MG, range 0.0-4.84 (median 2.86), samples 7
   USDA FoodData Central Foundation Foods, release 2026-04-30 · checked 2026-09-28
3. brpa-daily-r5-18 · portion data
   Bread, white | FNDDS code 51101000 | fdc_id 2707598 | 1 medium or regular slice 64355 = 28 g · Pasta, cooked | FNDDS code 56130000 | fdc_id 2708357 | 1 cup, cooked 10043 = 140 g | 1 oz, dry, yields 40049 = 80 g
   USDA FNDDS 2021-2023 · checked 2026-09-28
4. brpa-dga-02 · government guidance
   Whole grains serving goals: 2–4 servings per day, adjusting as needed based on your individual caloric requirements.
   U.S. Department of Health and Human Services and U.S. Department of Agriculture, Dietary Guidelines for Americans, 2025–2030 (January 2026), p. 3 · checked 2026-09-29
5. brpa-daily-r5-06 · randomized controlled trial
   The GI of R (63 ± 3) was statistically higher than that of S (44 ± 7) (p = 0.003).
   Nutr Metab Cardiovasc Dis, 2021 · checked 2026-09-28
6. brpa-daily-r5-11 · systematic review
   Results were inconclusive as acute postprandial studies increased non-haem iron bioavailability (especially in low-phytate breads); for example, low-phytate white bread produced a greater 2 h increase in serum iron than high-phytate wholemeal bread (59 vs. 30 μg Fe/100 mL), while exogenous phytase increased iron absorption by 50% for ferrous sulfate and 61% for iron bis-glycine chelate.
   Front Nutr, 2026 · checked 2026-09-28
7. brpa-daily-r5-19 · retention factor data
   USDA-RETN-R6:381 PASTA,BOILED,DRAINED, group Cereal Grains and Pasta (20): potassium_mg 30%, thiamin_mg 65%, niacin_mg 65%, folate_total_ug 70%, iron_mg 75%, riboflavin_mg 75%
   USDA Table of Nutrient Retention Factors, Release 6 (2007), code 381 · checked 2026-09-28
8. brpa-daily-r5-09 · meta-analysis of cohorts
   Meta-analyses of hazard ratios (HR) and 95% confidence intervals (CI) obtained from 17 prospective cohort studies (>875,000 participants) indicated that refined grain intake was not associated with risk of CVD (HR = 1.08, 95% CI, 0.99-1.18, I2 = 70%; 9 cohorts), stroke (HR = 1.06, 95% CI 0.92-1.23, I2 = 70%; 9 cohorts), or heart failure (HR = 0.95, 95% CI 0.77-1.16, I2 = 10%; 5 cohorts).
   Trends Cardiovasc Med, 2024 · checked 2026-09-28
9. brpa-daily-r5-10 · meta-analysis of cohorts
   Per 30-g increase in daily whole grain consumption, the RRs and 95% CIs of stroke, coronary heart disease (CHD), heart failure (HF), CVD, and all-cause mortality were 0.98 (0.96, 1.00), 0.94 (0.92, 0.97), 0.97 (0.89, 1.07), 0.92 (0.88, 0.96), and 0.94 (0.92, 0.97), respectively.
   Am J Clin Nutr, 2023 · checked 2026-09-28
10. brpa-dga-01 · government guidance
    Prioritize fiber-rich whole grains. ... Significantly reduce the consumption of highly processed, refined carbohydrates, such as white bread, ready-to-eat or packaged breakfast options, flour tortillas, and crackers.
    U.S. Department of Health and Human Services and U.S. Department of Agriculture, Dietary Guidelines for Americans, 2025–2030 (January 2026), p. 3 · checked 2026-09-29
11. brpa-daily-r5-12 · meta-analysis of food contamination data
    Following the initial evaluation, in 26.47% and 20.28% of all studies, the levels of Bap and PAH4 were higher than the permissible limit values, respectively.
    Compr Rev Food Sci Food Saf, 2024 · checked 2026-09-28
12. brpa-daily-r5-14 · agency fact sheet
    In January 1998, the U.S. Food and Drug Administration (FDA) began requiring manufacturers to add 140 mcg folic acid/100 g to enriched breads, cereals, flours, corn meals, pastas, rice, and other grain products [13] to reduce the risk of neural tube defects (NTDs).
    NIH Office of Dietary Supplements, Folate Fact Sheet for Health Professionals · checked 2026-09-28
13. brpa-daily-r5-01 · meta-analysis of RCTs
    Pasta in the context of low-GI dietary patterns significantly reduced body weight (MD=-0.63 kg; 95% CI -0.84 to -0.42 kg) and BMI (MD=-0.26 kg/m2; 95% CI -0.36 to -0.16 kg/m2) compared with higher-GI dietary patterns.
    BMJ Open, 2018 · checked 2026-09-28
14. brpa-daily-r5-08 · randomized controlled trial
    After 16 wk, there was no significant between-group difference in HbA1c [Δ = -0.01%, 95% confidence interval (CI): -0.03, 0.06; P = 0.49].
    Am J Clin Nutr, 2025 · checked 2026-09-28
15. brpa-daily-r5-15 · regulatory decision
    POL-HC-6873 Carbohydrates in pasta products Kolhydrater i pasta ger ett lågt och långsamt blodsockersvar/har ett lågt glykemiskt index (GI). Carbohydrates in pasta products provide a low and slow blood sugar response/have a low glycaemic index (GI). Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6873, snapshot 2026-09-21 · checked 2026-09-28
16. brpa-daily-r5-16 · regulatory decision
    POL-HC-8470 High-fibre sourdough rye bread Reduction of post-prandial glycaemic responses compared with glucose -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-8470, snapshot 2026-09-21 · checked 2026-09-28
17. brpa-webfix-1-01 · US federal regulation (agency explainer page)
    Examples of products that qualified for “healthy” under the original claim that do not under the updated claim include fortified white bread, highly sweetened yogurt, and highly sweetened cereal.
    US FDA, Use of the “Healthy” Claim on Food Labeling (final rule of December 19, 2024) · checked 2026-09-29
18. brpa-daily-r5-05 · randomized crossover trial
    The current evaluation showed that semolina spaghetti and wholegrain spaghetti can be classified as low GI products, with a GI of 53 and 54, respectively, significantly lower than wheat based mee pok noodles (74) and rice (80) (p < 0.005).
    Nutrients, 2021 · checked 2026-09-28
19. brpa-daily-r5-07 · randomized crossover trial
    Post-hoc analysis revealed a significant difference for the 30-minute postprandial blood glucose concentrations: the plasma glucose concentration was 57% higher for the GF rice and corn pasta compared to traditional wheat pasta (p = 0.011).
    Food Funct, 2017 · checked 2026-09-28
20. brpa-daily-r5-13 · cross-sectional study
    Median urinary iodine concentration was 49 (35, 78; 25, 75 centile) μg/L indicating iodine deficiency.
    Nutr Diet, 2026 · checked 2026-09-28
21. brpa-daily-r5-02 · meta-analysis of RCTs
    We identified no trial comparisons of the effect of pasta alone and 32 trial comparisons (n=2448 participants) of the effect of pasta in the context of low-GI dietary patterns.
    BMJ Open, 2018 · checked 2026-09-28
22. brpa-daily-r5-03 · systematic review and meta-analysis
    Pasta meals have significantly lower postprandial glucose response than bread or potato meals, but evidence was lacking in terms of how the intake of pasta can influence cardio-metabolic disease risk.
    Nutr Metab Cardiovasc Dis, 2017 · checked 2026-09-28