Melba toast: light in the hand, dense on the scale

Toasting bread dry does not make it gentler on blood sugar. In a randomized crossover trial of 12 healthy young adults, industrial rusk made from white bread had a glycemic index of 99 against 115 for the same bread, and the gap was not statistically significant. That trial is small, dates from 1988 and used French rusk, the closest product to melba toast we found. We found no trial of melba toast itself. In 17 people with type 2 diabetes, 2.1 oz (60 g) of hard toasted bread raised blood glucose no less than white bread with the same 50 g of carbohydrate. Gram for gram it is a dense food. The USDA survey table lists 390 calories, 76.6 g of carbohydrate and 598 mg of sodium per 3.5 oz (100 g) of melba toast. Its light reputation comes from weight: one toast is 5 g, about 20 calories, and a typical 18 g serving gives about 70 calories and 108 mg of sodium, figures calculated from the 100 g values.

What a real portion looks like

• In the USDA survey food table one melba toast weighs 5 g and the default serving is 18 g, so a typical serving gives about 70 calories and 108 mg of sodium. — USDA FNDDS survey food Melba toast, food code 51187000 Evidence E source
  1 melba toast 5 g (about 20 calories), quantity not specified 18 g (about 70 calories, 108 mg sodium), 1 cup 30 g

What cooking and storage change

• In a randomized crossover trial of 12 healthy adults, turning white bread into rusk by toasting did not meaningfully change its glycemic index, 99 for the rusk against 115 for the bread. — 12 healthy volunteers, 8 women and 4 men, mean age 24, each meal 35 g carbohydrate (n = 12) Evidence B source
  Glycemic index white bread 115 +/- 17%, rusk from the same bread 99 +/- 21%, bran rusk 87 +/- 21% (NS)

What it does to your health

• In a crossover trial of 11 healthy adults, a conventional flour cracker had a glycemic index of 90, while swapping 30% of the flour for sunflower seed flour brought it down to 53. — 11 healthy participants, mean age 23.5, 7 women, 50 g available carbohydrate per cracker meal (n = 11) Evidence B source
  GI control cracker 90, 30% whole wheat 77, 30% sunflower seed flour 53 (glucose scale)

Safety, limits and interactions

• A meta-analysis of 32 epidemiological publications found dietary acrylamide, which forms in toasted and baked starchy foods, unrelated to most common cancers, with a borderline signal only for kidney cancer. — epidemiological studies of dietary acrylamide intake and cancer at 14 sites, publications up to July 2014 (n = 32 publications) Evidence C source
  Kidney cancer RR 1.20 (95% CI 1.00 to 1.45) high vs low intake, continuous estimates 0.95 to 1.03 and none significant
• A dose-response meta-analysis of 16 cohort studies with over 1.1 million adults found no link between dietary acrylamide and site-specific non-gynecological cancer, except lung cancer in smokers. — 1,151,189 non-occupationally exposed adults followed a median 14.9 years, 48,175 cancers (n = 1151189) Evidence C source
  No association highest vs lowest exposure for each site, mean intake 23 micrograms a day

What people believe that the data does not support

• In the USDA survey food table melba toast carries 390 calories, 76.6 g of carbohydrate, 12.1 g of protein, 6.3 g of fiber and 598 mg of sodium per 3.5 oz (100 g). — USDA FNDDS survey food Melba toast, food code 51187000, WWEIA category Crackers, excludes saltines Evidence E source
  Energy 390 calories, carbohydrate 76.6 g, protein 12.1 g, fiber 6.3 g, sodium 598 mg, selenium 34.8 micrograms per 3.5 oz (100 g)

Who this works differently for

• In 17 people with type 2 diabetes, 2.1 oz (60 g) of hard toasted bread raised blood glucose no less than white bread, while potato dumplings gave a lower response. — 17 patients with type 2 diabetes, 11 men and 6 women, 50 g available carbohydrate per test food (n = 17) Evidence B source
  Only potato dumplings lowered glucose vs white bread (at 90, 120 and 150 min), starch hydrolysis about 30% lower for dumplings than for the other foods including toasted bread

The bottom line

Ordinary flour crackers behave much the same. In a crossover trial in 11 healthy adults, a plain flour cracker scored 90 on the glucose scale, and swapping 30 percent of the flour for whole wheat brought it only to 77. Sunflower seed flour in the same share brought it down to 53. Melba toast was not among the crackers tested. Per 100 g the USDA table also gives 12.1 g of protein and 6.3 g of fiber, so a 5 g toast carries a small share of either. The safety question people ask about is acrylamide, which forms when starchy foods are toasted or baked. We have no measurement of acrylamide in melba toast. A meta-analysis of 32 observational publications found dietary acrylamide unrelated to most common cancers, with a borderline signal for kidney cancer (relative risk 1.20, 95% CI 1.00 to 1.45, high against low intake). A pooled analysis of 16 cohorts with 1.15 million adults, followed for a median of 14.9 years at an average intake of 23 micrograms a day, found no link with any site-specific cancer it examined. Gynecological cancers were left out of that analysis. Both are observational, so they describe associations. We have no card on wheat allergy or celiac disease for this product.

Sources

1. mtc-r2-07 · reference dataset
   Melba toast | FNDDS 51187000 | fdc_id 2707702 | 1 melba toast 64654 = 5 g | 1 cracker 60609 = 5 g | Quantity not specified 90000 = 18 g | 1 cup, NFS 10010 = 30 g
   USDA FNDDS (FoodData Central survey 2024-10-31), food code 51187000 · checked 2026-10-02
2. mtc-r2-01 · randomized crossover trial
   The mean results of the glycemic indexes were: WB = 115 +/- 17%; FT = 99 +/- 21%; BFT = 87 +/- 21% (NS) with the corresponding insulin indexes at 81 +/- 8%, 79 +/- 9% and 90 +/- 8% respectively (NS). ... Neither the toasting process nor the presence of wheat bran had any major effect upon hyperglycemia and insulin secretion in the healthy subjects studied.
   Diabete Metab, 1988 · checked 2026-10-02
3. mtc-r2-03 · randomized crossover trial
   The SFC crackers provided low GI and GL values (GI: 53 on the glucose scale, GL: 6 per serving), whereas the WWC and CC crackers provided high GI (GI: 77 and 90 on the glucose scale, respectively) and medium GL values (11 and 12 per serving, respectively).
   Eur J Clin Nutr, 2024 · checked 2026-10-02
4. mtc-r2-04 · meta-analysis of observational studies
   The RR was of borderline significance only for kidney cancer (RR = 1.20; 95% confidence interval, CI, 1.00-1.45). All the corresponding continuous estimates ranged between 0.95 and 1.03, and none of them was significant.
   Int J Cancer, 2015 · checked 2026-10-02
5. mtc-r2-05 · meta-analysis of observational studies
   Out of 1,994 papers screened, 31 were eligible (total of 16 studies), which included 1,151,189 participants in total, out of whom 48,175 developed cancer during the median follow-up period of 14.9 years (range 7.3-33.9). The mean estimated dose of dietary acrylamide across studies was 23 μg/day. Pooled analysis showed no association between the highest vs. lowest dietary acrylamide exposure and each site-specific cancer investigated
   Front Nutr, 2022 · checked 2026-10-02
6. mtc-r2-06 · reference dataset
   Melba toast | FNDDS 51187000 | fdc_id 2707702 | Energy 390 kcal/100 g | Carbohydrate, by difference 76.6 g/100 g | Protein 12.1 g/100 g | Fiber, total dietary 6.3 g/100 g | Sodium, Na 598 mg/100 g | Selenium, Se 34.8 ug/100 g
   USDA FNDDS (FoodData Central survey 2024-10-31), food code 51187000 · checked 2026-10-02
7. mtc-r2-02 · randomized crossover trial
   All patients consumed, in random order and on alternate days, 50 g available carbohydrate provided by 90 g white bread and, according to a randomised procedure, an equivalent amount of carbohydrate provided by one (n 8) or two (n 9) of three other different test foods (g): pizza 85, potato dumplings 165, hard toasted bread 60. ... The percentage of starch hydrolysed after 5 h in vitro hydrolysis with alpha-amylase was about 30 % lower for potato dumplings than for the other foods.
   Br J Nutr, 2001 · checked 2026-10-02