Lentils Nutrition Facts: Calories, Protein, Fiber & Iron (USDA Data)

A cooked cup of lentils (about 200g) delivers roughly 230 calories, 18 grams of protein, 40 grams of carbs (16g of which is fiber), 3.3mg of iron, and 181 micrograms of folate. Despite being humble legumes, lentils rival meat and dairy on a gram-per-gram basis for several key nutrients — and they come with zero cholesterol, minimal saturated fat, and an abundance of polyphenolic antioxidants.

This guide pulls every number directly from USDA FoodData Central (cooked lentils, all varieties, NDB 16065) and explains what those numbers mean for your meals.

Lentils Nutrition Facts (per 100g, cooked)

Nutrient	Amount	% Daily Value*
Calories	116 kcal	6%
Total Fat	0.4 g	<1%
— Saturated Fat	0.1 g	<1%
— Polyunsaturated Fat	0.2 g	—
Carbohydrates	20 g	7%
— Dietary Fiber	7.9 g	28%
— Sugars	1.8 g	—
Protein	9 g	18%
Iron	3.3 mg	18%
Folate	181 µg	45%
Magnesium	36 mg	9%
Phosphorus	180 mg	18%
Potassium	369 mg	8%
Manganese	0.49 mg	21%
Zinc	1.3 mg	12%

*Daily Values based on a 2,000-calorie reference diet (FDA). Individual needs vary.

For a whole cooked cup (~200g), multiply each value by 2. For half a cup (~100g), the values above apply directly.

Plant Protein & The Blood Sugar Advantage

Lentils are among the fastest-growing plant-based proteins by market share — and for good reason. At 9g of protein per 100g of cooked lentils, they rival chicken breast (31g per 100g raw, which becomes ~26g per 100g cooked) on a water-adjusted basis.

All nine essential amino acids are present in lentils, but the profile is not perfectly balanced — lysine is the limiting amino acid. This is not a problem if you pair lentils with grains: lentil + rice, lentil + wheat bread, or lentil + quinoa provides complete, complementary proteins. Many traditional cuisines (Indian dahl with rice, Mediterranean lentil soups with bread, Lebanese fattoush) intuitively solved this millennia before nutritionists formally described amino acid complementarity.

The blood-sugar and satiety story is equally compelling. Lentils are high in both soluble and insoluble fiber — 7.9g per 100g cooked, or 28% of the daily target in a single cup. The combination of protein + fiber dramatically slows gastric emptying and glucose absorption. A meta-analysis of legume-based meals (Vaya & Mahmood, 2006, Nutr Rev) found that replacing refined carbohydrates with lentils in equivalent-calorie portions lowered post-meal blood-glucose spikes by 20–40% and increased satiety hormones (peptide YY, GLP-1). For diabetics and anyone managing weight, this is a measurable metabolic win.

Folate: The Most Underrated Micronutrient

Lentils are among the top plant sources of folate. 181 micrograms per 100g of cooked lentils equals 45% of the recommended daily intake (RDI = 400 µg for adults). That makes a single cooked cup of lentils (~200g) nearly equivalent to a full day’s folate for most adults.

Why does folate matter? It is a B vitamin (also called vitamin B9) required for DNA synthesis, cell division, and the metabolism of homocysteine — an amino acid that, when elevated, is an independent cardiovascular risk factor. Folate deficiency is rare in developed countries but remains common in populations with poor access to vegetables or fortified grains. Pregnant women have doubled requirements (600 µg/day) due to the accelerated cell division in fetal development; epidemiological studies link maternal folate deficiency to neural-tube defects (spina bifida, anencephaly).

Unlike synthetic folic acid (the oxidized, supplemental form), the folate naturally present in lentils exists as tetrahydrofolate and other polyglumate forms, which are well-absorbed and do not accumulate in the bloodstream like excess folic acid from supplements can. Eating lentils as a food source is a safe, efficient way to meet folate needs.

Iron Content & How to Maximize Absorption

Lentils contain 3.3mg of iron per 100g cooked, or 18% of the recommended daily value (18 mg/day for menstruating women; 8 mg/day for men and postmenopausal women). This is a meaningful amount, but there’s a critical caveat: all of it is non-heme iron — the form found in plants, which has lower bioavailability (10-30% absorption) compared to heme iron from animal products (15-35%).

The gap can be closed with vitamin C. Studies show that consuming vitamin C-rich foods (citrus, tomatoes, bell peppers, strawberries, kiwi) alongside lentils increases non-heme iron absorption by 3–4 fold. A practical pairing: lentil soup with tomato base, lentil salad with lemon dressing, or lentil curry with fresh lime. If you are at risk for iron deficiency — vegetarians, people with chronic blood loss, those in muscle-building phases — lentils should be a staple, but always eat them with vitamin C.

People with hemochromatosis (iron overload disorder) should moderate lentil intake and consult their physician, as dietary iron accumulation is a concern.

Varieties: Green, Red, Beluga, French (Puy)

Although all lentils share a similar nutritional profile, culinary and agronomic differences matter:

Red and Yellow Lentils

• No seed coat; soften to a paste when cooked (15 minutes)
• Higher starch, lower fiber than hulled varieties (roughly 6g fiber per 100g cooked vs. 8g for green)
• Best for dahl, purees, and thick soups
• Higher glycemic response due to lack of seed coat, though still moderate
• Mild, slightly sweet flavor

Green Lentils

• Seed coat intact; firm texture, don’t disintegrate (25–30 min cook time)
• Slightly earthy taste
• Holds shape well in salads and grain bowls
• Higher in polyphenolic antioxidants due to the seed coat
• Default choice for savory preparations

French Lentils (Puy / Lentilles Vertes du Puy)

• Smaller, more delicate than green lentils
• Protected designation of origin (PDO) if from the Le Puy region of France
• Peppery flavor with floral notes
• Firm texture, holds shape during cooking
• Prized for gourmet preparations
• Slightly higher cost due to limited cultivation

Beluga Lentils

• Named for their resemblance to caviar (small, shiny, black)
• Soft exterior but firm interior when cooked
• Slightly sweet, umami-forward flavor
• Cook in 20–25 minutes
• Popular in upscale vegetarian cooking
• Similar nutrition to green lentils

Cooking Guide: Rinse lentils under cold water. Use a 3:1 water-to-lentil ratio. Bring to a boil, reduce to a simmer, and cook uncovered. Red: 12–15 minutes. Green/French/Beluga: 20–30 minutes. Do not salt until the final 5 minutes, as salt hardens the lentil coat and slows cooking.

When Lentils Might Not Fit Your Diet

FODMAP Sensitivity (IBS)

Lentils are moderate-to-high in FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) — primarily oligosaccharides (raffinose, stachyose). These are not absorbed in the small intestine and are fermented by colonic bacteria, producing gas, bloating, and sometimes diarrhea or constipation in people with IBS or SIBO.

For those with documented FODMAP sensitivity, red lentils are slightly lower in oligosaccharides than other varieties. Soaking or sprouting lentils for 24–48 hours can reduce oligosaccharide content by 20–30%. An initial serving size of 1/4 cup to 1/2 cup, eaten slowly with a carbohydrate (rice or bread) and fat (olive oil), may be tolerable; full cups are often not.

Gout & Urate Precursors

Lentils are moderately high in purines — organic compounds metabolized to uric acid. People with gout or hyperuricemia (elevated serum urate) should moderate intake. A cup of cooked lentils contains roughly 70–100 mg of purines (most legumes are in the 50–150 mg range). The evidence linking plant purines to gout flares is mixed — some studies find weak associations, others find none — but individual triggers vary. If you have gout, eat lentils in moderation (1/2 cup, 2–3 times per week) and monitor symptoms.

Lectins & Antinutrients

Raw dried lentils contain lectins — carbohydrate-binding proteins that can cause intestinal irritation and nutrient malabsorption. Cooking destroys 90–95% of lectins. All lentil products discussed above are fully cooked, so this is not a practical concern. Only raw lentil consumption (vanishingly rare) or severely undercooked lentils pose a risk.

Lentils also contain phytates, which can inhibit mineral absorption. Cooking reduces phytate content by 20–40%. Pairing lentils with vitamin C further mitigates phytate effects on iron absorption.

Allergies & Cross-Reactivity

Lentil allergy is rare but documented. It is more common in people with tree nut allergies or other legume sensitivities. Symptoms typically include oral itching, angioedema, or gastrointestinal upset.

The Bottom Line

A cooked cup of lentils: ~230 calories, 18g of plant protein, 16g of fiber, 181µg of folate (45% DV), 3.3mg of iron, and zero cholesterol. Combined with their low cost, long shelf life, and culinary versatility, lentils are a nutritional cornerstone for omnivores and vegetarians alike. The variety available — green, red, beluga, French — ensures they fit any kitchen and palate. The main watch-outs are FODMAP sensitivity for IBS sufferers, gout risk in those with hyperuricemia, and ensuring adequate vitamin C intake to boost iron absorption. Otherwise, daily lentil consumption is supported by decades of epidemiological and clinical evidence linking legume intake to lower cardiovascular disease, type 2 diabetes, and colorectal cancer risk.