Black beans vs refried beans: the same cup, half the fiber

Beans lower LDL cholesterol, and that is the firmest finding on this page. A 2026 meta-analysis of 38 trials in 2,095 people, run for a median of 6 weeks at a median of 4.6 oz (130 g) a day, found that whole pulses cut LDL by 5.4 mg/dL (95% CI 3.1 to 7.3; metric: 0.14 mmol/L, 0.08 to 0.19). Those trials pooled pulses of every kind, so black beans were not tested on their own. For beans as a group, each extra half cup a day went with LDL 9.7 mg/dL (0.25 mmol/L) lower, up to a cup a day, with a wide interval of 0.02 to 0.48. Black and refried beans part ways in the can. In USDA survey data a cup of canned black beans (180 g) gives about 241 calories, 18.2 g fiber and 626 mg sodium. A cup of refried beans (260 g) has almost the same energy, 234 calories, with 9.6 g fiber and 962 mg sodium. Both cups are scaled from 100 g values, and the salt in canned beans depends heavily on the brand and on whether you drain the liquid.

How much is actually in it

• Per 100 g, canned black beans without added fat have 134 calories, 10.1 g fiber and 8.9 g protein, while refried beans have 90 calories, 3.7 g fiber and 5.0 g protein. — USDA FNDDS 2021-2023: Black beans, from canned, no added fat (41102080); Refried beans (41205010) Evidence E source
  Per 100 g black vs refried: energy 134 vs 90 calories, fiber 10.1 vs 3.7 g, protein 8.87 vs 4.98 g, fat 0.43 vs 2.01 g, saturated fat 0.11 vs 0.631 g, sodium 348 vs 370 mg, iron 2.79 vs 1.44 mg, folate 85 vs 10 ug DFE
• Lab samples of canned pinto refried beans ranged from 3.2 to 5.0 g fiber per 3.5 oz (100 g), and vegetarian refried beans from 256 to 306 mg sodium. — USDA FoodData Central Foundation Foods: Refried beans, canned (pinto), 6 samples; Refried beans, canned, vegetarian, 2 samples Evidence E source
  Fiber mean 3.868 g (3.17-4.97, n=6); sodium mean 281 mg (256-306, n=2); iron 1.535 mg (1.34-1.73, n=2)

What a real portion looks like

• A cup of canned black beans (180 g) gives about 241 calories, 18 g fiber and 626 mg sodium, and a cup of refried beans (260 g) about 234 calories, 9.6 g fiber and 962 mg sodium. — USDA FNDDS 2021-2023 portions, 1 cup: black beans canned no added fat 180 g; refried beans 260 g Evidence E source
  Per cup black vs refried: 241 vs 234 calories, fiber 18.2 vs 9.6 g, protein 16.0 vs 12.9 g, sodium 626 vs 962 mg

What your body absorbs

• In two crossover RCTs of 55 young and older adults, two ounce-equivalents of black beans delivered 3.02 g essential amino acids, less than pork (7.36 g) or eggs (5.38 g). — Young (n = 30) and older adults (n = 25), standardized meal with two oz-eq portions (n = 55) Evidence B source
  EAA content 3.02 g black beans vs 7.36 g pork, 5.38 g eggs; lower postprandial EAA bioavailability (p < 0.0001)
• In a crossover trial of 10 young and 10 older adults eating 20 g protein, age cut lysine and threonine uptake from sorghum by 19% but not from black beans. — Ten young (21.8 y) and 10 older (72.8 y) adults, 20 g labeled protein per test day (n = 20) Evidence B source
  Older vs young isotope ratio: sorghum -19% (P = 0.041); black beans no difference (P = 0.849)
• In Guatemalan girls aged 12-13, only 5.5-9.0% of fortification iron was absorbed from meals of corn tortillas and black bean paste, depending on the iron form. — Guatemalan girls aged 12-13 y, stable-isotope crossover Evidence B source
  Iron bioavailability 5.5-6.2% ferrous fumarate, 5.5% ferrous sulfate, 9.0% NaFeEDTA (P = 0.009)

What cooking and storage change

• By the USDA table for legumes boiled and then fried, as in refried beans, about 60% of folate and 65% of thiamin remain, while 90% of iron and zinc stay. — USDA Table of Nutrient Retention Factors, Release 6, Legumes and Legume Products, method code 506 Evidence E source
  Retained: folate 60%, thiamin 65%, niacin 70%, vitamin B6 70%, potassium 80%, magnesium 85%, iron 90%, zinc 90%

What it does to your health

• A 2026 meta-analysis of 38 trials in 2095 people found whole pulses cut LDL cholesterol by 5.4 mg/dL (0.14 mmol/L), and for beans LDL fell linearly with intake up to 1 cup a day. — 38 trials (52 comparisons), n = 2095, median 6 weeks, median 130 g/d (n = 2095) Evidence A source
  LDL-C MD -5.4 mg/dL (95% CI -7.3 to -3.1; metric: -0.14 mmol/L, -0.19 to -0.08); beans -9.7 mg/dL (-0.25 mmol/L) per 0.5 cup (95% CI -0.48 to -0.02)
• In a crossover trial of 17 adults with type 2 diabetes, black beans with rice (50 g carbohydrate) lowered the blood glucose area under the curve versus rice alone. — Seventeen men and women with type 2 diabetes aged 35-70, 50 g available carbohydrate at breakfast (n = 17) Evidence B source
  Lower net glucose at 90, 120 and 150 min and lower iAUC for black bean/rice vs rice; exact sizes not in abstract
• In a crossover trial of 35 older adults, a breakfast tortilla with 135 g black beans was as filling as one with 80 g beef, with no difference in lunch or 24-hour intake. — Older adults, n = 35, age 72.4 y, 1 serving black beans (135 g), red kidney beans (135 g) or beef (80 g) (n = 35) Evidence B source
  No significant difference in appetite AUCs, ad libitum pizza intake or 24-h energy intake
• In a crossover trial of 12 adults with metabolic syndrome, a Western-style meal with black beans gave a lower insulin response than fiber- or antioxidant-matched meals. — 12 adults with metabolic syndrome, three meals, 5 h postprandial (n = 12) Evidence B source
  Insulin lower after black bean meal vs fiber-matched or antioxidant-matched (p < 0.0001)

Safety, limits and interactions

• Across 3 feeding trials of half a cup of beans daily for 8-12 weeks, fewer than 50% reported more gas in the first week with pinto or baked beans, 19% with black-eyed peas, and 3-11% on control diets. — Adults in 3 feeding studies (n = 17, 29, 80), 1/2 cup pinto beans, black-eyed peas or baked beans daily for 8-12 weeks (n = 126) Evidence B source
  <50% reported increased flatulence with pinto or baked beans in week 1; 19% with black-eyed peas; 3-11% on control diets

The bottom line

Brands of refried beans differ less than you might expect. Six lab samples of canned pinto refried beans ranged from 3.2 to 5.0 g fiber per 3.5 oz (100 g), and two samples of vegetarian refried beans from 256 to 306 mg sodium, all from cans, with no homemade versions measured. Per 100 g, the survey records give canned black beans 85 micrograms of folate against 10 in refried beans. The USDA retention table for legumes boiled and then fried, the way refried beans are made, keeps about 60% of folate, 65% of thiamin and 90% of iron and zinc, as a group factor for all legumes on a table dated 1975. As protein, black beans are modest. In two crossover trials in 55 young and older adults, a two ounce-equivalent portion of black beans carried 3.02 g of essential amino acids against 7.36 g for pork and 5.38 g for eggs, and less of them reached the blood (p < 0.0001). Those portions were matched by the US dietary guideline unit, not by grams of protein. Age did not blunt that uptake in a smaller trial. In 10 young and 10 older adults, lysine and threonine from black beans showed no difference between the two ages (P = 0.849), while uptake from sorghum was 19% lower in the older group, measured with a dual tracer method that rests on its own assumptions. Iron added to a bean meal was poorly absorbed in one study. Guatemalan girls aged 12 to 13 took up only 5.5% to 9.0% of the iron added to corn tortillas and black bean paste, depending on the iron compound, and that was fortification iron in a study whose abstract gives no sample size, so it says nothing direct about the iron the beans themselves carry. The meal tests are short and small. In 17 adults with type 2 diabetes, black beans with rice gave a smaller blood glucose area under the curve than the same 50 g of carbohydrate from rice alone, in a single-meal test whose abstract gives no size for the gap. In a pilot of 12 adults with metabolic syndrome, a Western-style meal with black beans produced a lower insulin response than meals matched for fiber or antioxidants (p < 0.0001). In 35 older adults, a breakfast tortilla with 4.8 oz (135 g) of black beans was as filling as one with 2.8 oz (80 g) of beef, with no difference at lunch or across 24 hours. The caution with evidence behind it is gas. In three feeding trials in 126 adults eating half a cup of beans daily for 8 to 12 weeks, fewer than half reported more gas in the first week with pinto or baked beans and 19% with black-eyed peas. Between 3% and 11% reported more gas on control diets with no beans. All of this was self-reported, and black beans were not among the beans tested. If you watch sodium, the cup of refried beans at 962 mg is the number to keep in mind. We have no card on allergy, pregnancy or drug interactions for either bean.

Sources

1. bbrf-daily-r3-01 · reference dataset
   FNDDS 2707363 Black beans, from canned, no added fat: Energy 134 kcal · Fiber, total dietary 10.1 g · Protein 8.87 g · Total lipid (fat) 0.43 g · Fatty acids, total saturated 0.11 g · Sodium 348 mg · Iron 2.79 mg · Folate, DFE 85 ug per 100 g || FNDDS 2707396 Refried beans: Energy 90 kcal · Fiber, total dietary 3.7 g · Protein 4.98 g · Total lipid (fat) 2.01 g · Fatty acids, total saturated 0.631 g · Sodium 370 mg · Iron 1.44 mg · Folate, DFE 10 ug per 100 g
   USDA FNDDS 2021-2023 · checked 2026-09-30
2. bbrf-daily-r3-02 · reference dataset
   Refried beans, canned (pinto): Fiber, total dietary 3.868 g, range 3.17-4.97, n=6 · Fatty acids, total saturated 0.6417 g, range 0.43-0.81, n=6 · Refried beans, canned, vegetarian: Sodium 281.0 mg, range 256.0-306.0, n=2 · Iron 1.535 mg, range 1.34-1.73, n=2
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-30
3. bbrf-daily-r3-03 · reference dataset
   FNDDS 2707363 Black beans, from canned, no added fat, 1 cup 180 g: Energy 241.2 kcal · Fiber 18.2 g · Protein 16.0 g · Sodium 626.4 mg || FNDDS 2707396 Refried beans, 1 cup 260 g: Energy 234.0 kcal · Fiber 9.6 g · Protein 12.9 g · Sodium 962.0 mg
   USDA FNDDS 2021-2023 · checked 2026-09-30
4. bbrf-daily-r3-05 · RCT (crossover)
   Two oz-eq portions of pork (7.36 g EAA) and eggs (5.38 g EAA) resulted in greater EAA bioavailability than black beans (3.02 g EAA) and almonds (1.85 g EAA) in young and older adults, separately or combined (p < 0.0001 for all).
   Nutrients, 2023 · checked 2026-09-30
5. bbrf-daily-r3-06 · RCT (crossover)
   The isotope plasma-to-meal ratio for lysine and threonine was 19% lower in older adults compared with young adults for sorghum (P = 0.041), whereas it was not significantly different for milk (P = 0.277) and black beans (P = 0.849).
   Am J Clin Nutr, 2026 · checked 2026-09-30
6. bbrf-daily-r3-07 · RCT (crossover)
   Geometric mean iron bioavailability from test meals fortified with ferrous sulfate was 5.5% and was significantly higher in test meals fortified with NaFeEDTA (9.0%; P = 0.009, paired t test).
   Am J Clin Nutr, 2002 · checked 2026-09-30
7. bbrf-daily-r3-04 · reference dataset
   USDA-RETN-R6:506 LEGUMES,CKD 15/20MIN,BOILED+FRIED, group Legumes and Legume Products: folate_total_ug 60% retained, thiamin_mg 65%, niacin_mg 70%, vitamin_b6_mg 70%, potassium_mg 80%, magnesium_mg 85%, iron_mg 90%, zinc_mg 90%
   USDA Table of Nutrient Retention Factors, Release 6 (2007), code 506 · checked 2026-09-30
8. bbrf-daily-r3-08 · meta-analysis
   A linear inverse relationship was shown for beans up to 1 cup/d for low-density lipoprotein-cholesterol (coefficient, -0.25 mmol/L/0.5 cup [95% CI, -0.48 to -0.02]) and non-high-density lipoprotein-cholesterol (-0.45 mmol/L/0.5 cup [95% CI, -0.71 to -0.18]).
   J Am Heart Assoc, 2026 · checked 2026-09-30
9. bbrf-daily-r3-09 · RCT (crossover, acute)
   Incremental area under the curve values were significantly lower for the pinto and black bean/rice meals compared to rice alone, but not for kidney beans.
   Nutr J, 2012 · checked 2026-09-30
10. bbrf-daily-r3-10 · RCT (crossover)
    Appetite sensation AUCs, ad libitum pizza intake, and 24-h energy intake did not significantly differ between the test meals.
    J Nutr, 2025 · checked 2026-09-30
11. bbrf-daily-r3-11 · RCT (crossover, acute)
    Insulin was lower after the BB meal, compared to the FM or AM meals (p < 0.0001).
    Nutrients, 2015 · checked 2026-09-30
12. bbrf-daily-r3-12 · RCT
    Less than 50% reported increased flatulence from eating pinto or baked beans during the first week of each trial, but only 19% had a flatulence increase with black-eyed peas. A small percentage (3-11%) reported increased flatulence across the three studies even on control diets without flatulence-producing components.
    Nutr J, 2011 · checked 2026-09-30