Kidney Beans
Kidney beans are nutrient-dense legumes rich in plant-based protein, fiber, and essential minerals, making them a cornerstone food for sustained energy and metabolic health.
Nutrition · per ~90 g serving · ≈ ½ cup cooked
- Folate117.0 mcg29% DV
- Copper0.22 mg24% DV
- Manganese0.43 mg19% DV
- Iron2.0 mg11% DV
- Phosphorus124.2 mg10% DV
- Potassium362.7 mg8% DV
- Inulin / Prebiotic fibre~2.7 g
- Polyphenols~135 mg
Score · 77/100
Vitamins & minerals packed in relative to calories — the single biggest driver of the score.
How much protein it delivers, by absolute grams and per calorie.
Dietary fiber for gut health, satiety and steadier blood sugar.
Fat quality — unsaturated vs saturated, and trans-fat free.
Polyphenols, flavonoids and other beneficial plant compounds for this food group.
Low sugar with a high fiber-to-carb ratio scores best — gentler on blood sugar.
- Folate33% DV
- Copper27% DV
- Manganese21% DV
- Iron12% DV
- Phosphorus11% DV
Overview
Kidney beans (Phaseolus vulgaris) originated in Mesoamerica and have been cultivated for over 7,000 years. These dark red legumes are exceptional sources of plant-based protein (8.7g per 100g) and resistant starch, which resists digestion and acts as a prebiotic. Their high fiber content (6.4g per 100g) supports gut microbiome diversity—a key longevity marker. Kidney beans provide substantial folate (130 mcg), critical for homocysteine regulation and cardiovascular health, along with bioavailable iron and polyphenolic compounds including flavan-3-ols and anthocyanins. The resistant starch and soluble fiber lower postprandial glucose spikes, improving insulin sensitivity over time. Their mineral profile—particularly potassium (403mg) and manganese—supports bone health and metabolic enzyme function. Regular legume consumption is associated with reduced all-cause mortality risk and improved lipid profiles. Kidney beans also contain phytochemicals like kaempferol, linked to anti-inflammatory and neuroprotective effects in observational studies.
Health Benefits (5)
- Improves insulin sensitivity and reduces postprandial glucose spikesstrongResistant starch and soluble fiber slow carbohydrate digestion and absorption, reducing blood glucose fluctuations and lowering insulin demand
- Supports cardiovascular health through lipid and homocysteine reductionstrongSoluble fiber binds cholesterol; folate reduces homocysteine; polyphenols reduce oxidative stress and endothelial inflammation
- Enhances gut microbiome diversity and short-chain fatty acid productionmoderateResistant starch and fiber serve as prebiotics, feeding beneficial bacteria like Faecalibacterium and Roseburia, which produce butyrate for intestinal barrier integrity
- Increases sustained satiety and supports healthy body compositionmoderateHigh protein and fiber content delays gastric emptying and activates satiety hormones (GLP-1, PYY), reducing overall caloric intake
- Supports bone mineral density through mineral and phytochemical contentemergingManganese, phosphorus, and polyphenolic compounds promote osteoblast activity and reduce bone resorption markers
Food Pairings
- ·Pair with vitamin C-rich foods (tomatoes, bell peppers, citrus) to enhance non-heme iron absorption by up to 3-fold
- ·Combine with whole grains (brown rice, quinoa) to create a complete amino acid profile with all nine essential amino acids
- ·Mix with leafy greens (spinach, kale) to amplify folate intake and polyphenol diversity for enhanced antioxidant effect
- ·Pair with allium vegetables (garlic, onions) to synergize sulfur compounds and organosulfurs for enhanced anti-inflammatory activity
Practical Tips
- ·Soak dried kidney beans for 12 hours and discard water to reduce lectins and phytates, improving mineral bioavailability and digestibility
- ·Cook beans with kombu seaweed or a small piece of ginger to further reduce oligosaccharides that cause bloating
- ·Store cooked beans in glass containers for up to 5 days; freeze portions for up to 3 months to preserve resistant starch content
- ·Include kidney beans in 2-3 meals weekly (½ to ¾ cup cooked portions) to achieve prebiotic and cardiometabolic benefits documented in research
Optimal Timing
Kidney beans' combination of protein and resistant starch provides sustained energy and stable glucose through the afternoon. Midday consumption optimizes satiety duration and prevents late-day energy crashes without interfering with sleep-promoting serotonin timing.
- · immediately before bed (high fiber may cause mild bloating; allow 2-3 hours digestion time)
Can be included in overnight oats or breakfast Buddha bowls if gradually introduced and well-tolerated; start with smaller portions if new to high-fiber legumes.
Systems supported
body systems this food feedsPathways supported
biochemical reactions enabled by this foodCompared to other legumes
Per 100 g of the default form. Bars show how much higher or lower kidney beans is than the average across 26 peer foods in this category. Green means a favorable direction; amber means the opposite.
What people ask about kidney beans
What is kidney beans?
Kidney Beans is classified as a legume. Kidney beans are nutrient-dense legumes rich in plant-based protein, fiber, and essential minerals, making them a cornerstone food for sustained energy and metabolic health.
Is kidney beans healthy?
Kidney Beans scores 77/100 in Formulate, making it a solid choice. Its strongest contributions come from Folate, Copper, Manganese. The score blends nutrient density, fiber, healthy fats, protein quality, bioactive compounds, and glycemic impact.
Is kidney beans high in protein?
Moderately — it contributes meaningful protein. A 90 g serving provides about 7.8 g of protein (~16% of the 50 g daily value).
Is kidney beans high in fiber?
Yes — it's a high-fiber food. A 90 g serving provides about 5.8 g of fiber (~21% of the 28 g daily value).
What vitamins and minerals are in kidney beans?
In a 90 g serving, kidney beans is highest in Folate (~29% DV), Copper (~24% DV), Manganese (~19% DV), Iron (~11% DV).
Is kidney beans keto-friendly?
Not really. A 90 g serving has about 14.8 g of net carbs (20.5 g total minus 5.8 g fiber).
When is the best time to eat kidney beans?
Best in the midday. Kidney beans' combination of protein and resistant starch provides sustained energy and stable glucose through the afternoon. Midday consumption optimizes satiety duration and prevents late-day energy crashes without interfering with sleep-promoting serotonin timing.
How much kidney beans should I eat?
A typical serving is around 90 g (~114 kcal), based on the FDA's Reference Amount Customarily Consumed for this food category. There's no fixed daily target — most adults benefit from rotating kidney beans alongside several other legume sources.
What pairs well with kidney beans?
Kidney Beans pairs nicely with: Pair with vitamin C-rich foods (tomatoes, bell peppers, citrus) to enhance non-heme iron absorption by up to 3-fold; Combine with whole grains (brown rice, quinoa) to create a complete amino acid profile with all nine essential amino acids; Mix with leafy greens (spinach, kale) to amplify folate intake and polyphenol diversity for enhanced antioxidant effect; Pair with allium vegetables (garlic, onions) to synergize sulfur compounds and organosulfurs for enhanced anti-inflammatory activity.
Supplements that mirror Kidney Beans's nutrient profile
Encyclopedia entries that supply the same signature nutrients kidney beans contributes. Click through to see clinical dose ranges, evidence quality, and bioavailable forms.
Signature nutrients in Kidney Beans
These are the nutrients kidney beanscontributes meaningfully toward (≥10% DV per 100 g serving). Click one to see what it does in the body, which supplements concentrate it, and which other foods are top sources.