Black beans vs pinto beans: which has more protein?
Full comparison · Protein · Calories · Carbs
Black beans and pinto beans have about the same protein: 8.9 g vs 9 g per 3.5 oz (100 g). The difference is per calorie: 6.7 g vs 6.3 g per 100 calories.
USDA FoodData Central.
| Black beans | Pinto beans | |
|---|---|---|
| Per 3.5 oz (100 g) | 8.9 g | 9 g |
| Per serving | 15.2 g in 1 cup (6.1 oz, 172 g) | 15.4 g in 1 cup (6 oz, 171 g) |
| Per 100 calories | 6.7 g | 6.3 g |
| To get 30 g of protein | 11.9 oz (339 g), about 2.0 × 1 cup | 11.7 oz (333 g), about 1.9 × 1 cup |
Protein per calorie
Per 100 calories, black beans gives 6.7 g of protein and pinto beans 6.3 g. This is the number that matters when you are fitting protein into a calorie budget, and it can rank foods differently from grams per 3.5 oz (100 g).
What the numbers don't tell you
For a burrito bowl or chili, pick either. Cooked, they sit within 11 calories and a fraction of a gram of protein and fiber of each other per 3.5 oz (100 g), and in a blood sugar trial of both, they behaved alike.
In adults with mildly high cholesterol, 6 weeks of a daily bean mix that included black and pinto beans lowered LDL by about 8.1 mg/dL (0.21 mmol/L) against rice. The mix cannot separate the two. In 17 adults with type 2 diabetes, either bean eaten with rice gave a smaller blood sugar rise than rice alone, a small-to-medium effect, in single meals.
The table hides one thing. Bean protein is less complete than meat: two ounce-equivalents of black beans supplied 3.02 g of essential amino acids against 7.36 g from pork, and less of it reached the blood.
The gas fades. With half a cup of pinto beans a day, fewer than half of adults reported more flatulence in the first week, and 6% by the second, close to the 3 to 11% on bean-free diets. If you cook dry beans, 1 oz dry makes about 2.5 oz (70 g) cooked. Boil them for at least 30 minutes and skip the slow cooker, FDA's advice for a toxin found in many beans and highest in red kidney beans.
Evidence behind this note
- Level B In a 6-week RCT in adults with mild hypercholesterolemia, a daily bean mix including black and pinto beans lowered LDL cholesterol by 0.21 versus rice, while peas did not. J Nutr, 2024
- Level B In a crossover RCT in 17 adults with type 2 diabetes, pinto bean and black bean meals with rice (50 g available carbohydrate) gave a lower glucose area under the curve than rice alone. Nutr J, 2012
- Level B In the same 17-person type 2 diabetes crossover, pinto and black bean rice meals both lowered glucose iAUC versus rice over 0-180 min, with medium effect sizes (d about 0.4 to 0.5). Nutr J, 2012
- Level B In two crossover RCTs in 55 young and older adults, two ounce-equivalents of black beans supplied 3.02 g essential amino acids versus 7.36 g from pork and gave lower EAA bioavailability. Nutrients, 2023
- Level B Across 3 feeding trials of 1/2 cup beans a day for 8-12 weeks, fewer than 50% reported more flatulence from pinto beans in the first week, and 3-11% did so even on control diets. Nutr J, 2011
- Level B In the crossover feeding trials, reports of increased flatulence from half a cup of pinto beans a day fell from 50% of participants in the first week to 6% by the second week. Nutr J, 2011
- Level E FDA's Bad Bug Book says the lectin phytohaemagglutinin occurs in many species of beans and is highest in red kidney beans, and advises boiling beans for at least 30 minutes and never cooking them, or dishes containing them, in a slow cooker. FDA, Bad Bug Book: Foodborne Pathogenic Microorganisms and Natural Toxins, 2nd edition, 2012, chapter Phytohaemagglutinin
- Level E FNDDS weighs 1 cup of cooked black beans and of cooked pinto beans (from dried, no fat) at 180 g, and 1 oz dry yields 70 g cooked. USDA FNDDS 2021-2023, codes 41102020 and 41104020
Written from the studies and agency guidance we hold for both foods, reviewed by the Bioma editorial system. How we verify.
Keep exploring
Read more about these foods
- Black beans and pinto beans: close cousins tested in small trials
- Black beans: half a cup a day, and the phytate costs you half your iron
- Pinto beans: a cup a day moves LDL, and the gas fades by week two
Rankings and guides
- Which foods are highest in protein?
- Which foods give the most protein for the fewest calories?
- How much protein do you need per day?
- Protein: what it does and how much you need
- Protein: top food sources and Daily Value
- Black beans: full nutrition facts
- Pinto beans: full nutrition facts
More comparisons
Where the numbers come from
- Black beans: USDA FoodData Central, Beans, black, mature seeds, cooked, boiled, without salt, FDC ID 173735 · full profile · all forms of black beans
- Pinto beans: USDA FoodData Central, Beans, pinto, mature seeds, cooked, boiled, without salt, FDC ID 175200 · full profile · all forms of pinto beans
Each food is one USDA entry, chosen as it is usually eaten. Other cuts, brands and preparations differ; the links show them. % DV uses FDA Daily Values for adults. How we verify.