Leucine-Rich Foods: Which Foods Are Highest in Leucine?

Quick answer. The foods highest in leucine are protein-rich foods. In USDA data, a typical serving of cottage cheese, cooked soybeans, chicken breast, lean beef, salmon or canned tuna provides about 1.3 to 2.9 g, while a serving of beans, lentils, tofu, nuts or seeds provides about 0.4 to 1.3 g. Leucine is about 6 to 10% of their protein, so the protein in a serving matters more than any single "leucine food." The per-meal "leucine threshold" of 2 to 3 g comes from short studies, mostly of protein drinks, and reviews have not confirmed a fixed cutoff. U.S. authorities have not set an upper limit for leucine, but people with maple syrup urine disease must restrict it under medical care.

Which foods are highest in leucine

Values are USDA FoodData Central SR Legacy records (last updated April 2019), with USDA portion weights. Meat, fish, eggs, beans and grains are cooked unless noted. The last column is our calculation (leucine divided by protein).

Raw chicken breast has 1.86 g of leucine per 100 g (FDC 171077) and roasted breast 2.33 g, because cooking removes water; spirulina tops the per-100 g list, but a tablespoon gives 0.35 g.

Animal vs plant foods: leucine share and protein amount

In USDA records, leucine is 7.5 to 10.2% of protein in animal foods and 5.9 to 8.6% in plant foods other than grapefruit. Meat and fish (7.5 to 8.1%) overlap with soybeans, black beans and pumpkin seeds (7.5 to 8.0%). The larger difference is protein per serving: about 27 g in half a roasted chicken breast, 18 g in a cup of lentils.

A 2018 lab analysis of 35 commercial protein isolates found leucine averaged 7.1% of protein in plant isolates and 8.8% in animal isolates, from 5.1% in hemp to 13.5% in corn (whey 11.0%, egg 7.0%); plant proteins were also lower in lysine and methionine. Matching the 2.7 g of leucine in 25 g of whey would take about 38 g of pea, 40 g of soy or 54 g of hemp protein, the authors calculated. Every food in the table except grapefruit matches or exceeds the leucine level in the WHO/FAO/UNU adult scoring pattern (59 mg per gram of protein) and the U.S. and Canadian one (55 mg/g).

What the research says about leucine per meal

The per-meal idea draws on rat studies; in one, peak muscle protein synthesis (MPS) after a meal tracked the meal's leucine content. Short human studies, mostly of drinks, then found:

• In older adults, 6.7 g of essential amino acids raised MPS only when 41% was leucine (about 2.7 g), not 26% (about 1.7 g; our calculation); young adults responded to both.
• In 40 young men who did leg exercise, MPS 1.5 to 4.5 hours after a drink was highest after 25 g of whey (3.0 g of leucine) and after 6.25 g of whey with added leucine (5.0 g in total).
• Pooled data showed MPS leveling off at about 0.24 g of protein per kg per meal in young men and 0.40 g/kg in older men.

The International Society of Sports Nutrition (ISSN) suggests 700 to 3,000 mg of leucine per protein dose, but one systematic review found the "leucine trigger" supported in 16 of 29 studies, mostly in older adults given isolated proteins, and less relevant to whole foods; another found that leucine dose tracked post-exercise MPS in older but not younger adults, with no clear threshold. Our leucine research review covers them.

By USDA values, 2.5 to 3 g is about a cup of cottage cheese, a 165-g can of light tuna, 2 cups of cooked lentils or 5 large eggs. These are study amounts, not targets.

What human studies have tested

RCT = randomized controlled trial. MPS is reported in %/h or %/day.

In single meals, protein amount and the food both mattered: one 113-g beef patty worked as well as three, and whole eggs beat egg whites despite similar leucine availability. Over days to weeks, vegan and omnivorous diets with matched, adequate protein gave similar results, and higher-leucine whey matched milk. When older adults chose their own vegan diet, protein intake fell and they lost thigh muscle. Evidence strength: consistent that protein amount matters; limited on whether a food's leucine share matters once protein is matched. Most trials were small; many included only men.

Official intake references

• WHO/FAO/UNU (2007): 39 mg of leucine per kg of body weight a day for adults.
• U.S. Dietary Reference Intakes (Institute of Medicine, 2005): for adults, an Estimated Average Requirement (EAR) of 34 mg/kg a day and a Recommended Dietary Allowance (RDA) of 42 mg/kg a day.

For a 70-kg adult, 34 to 42 mg/kg is about 2.4 to 2.9 g a day (our calculation). Germany's Federal Institute for Risk Assessment (BfR) reports average intakes of about 6.1 g a day in the U.S. and 108 mg/kg a day (median) in UK adults. A 2021 tracer study in 16 adults over 60 estimated their need at 78.5 mg/kg a day, which its authors call more than double current recommendations.

Is food a source of HMB?

Earlier versions of this page listed HMB food sources. About 5% of the body's leucine becomes HMB, says the NIH Office of Dietary Supplements (ODS), and ODS and the ISSN estimate that the 3 g a day of HMB used in studies would take about 60 g of leucine, from more than 600 g of high-quality protein. We found no PubMed study measuring HMB in common foods. Food cannot supply HMB at study amounts; see our HMB article.

Practical points the evidence supports

• Compare foods per serving, raw or cooked as eaten.
• For most protein foods in the table, grams of protein times 0.07 to 0.10 gives a rough leucine estimate (our calculation).
• Diet trials that found plant-based and mixed diets equal matched total protein; where muscle declined, protein intake had fallen.
• These are study findings, not dosing advice; ask a healthcare professional.

Safety

Upper limits. The U.S. Food and Nutrition Board could not derive an upper limit for leucine, according to BfR. BfR's 2019 guidance value of 4.0 g a day covers only supplemental leucine in adults, not people with reduced kidney function; it advises children, adolescents and pregnant or breastfeeding women to avoid relevant intakes of isolated branched-chain amino acids. In rising-dose tests in 11 healthy young and older men, blood ammonia rose above normal above 500 to 550 mg/kg a day (about 35 g at 70 kg).

Maple syrup urine disease (MSUD). This inherited disorder, affecting about 1 in 185,000 infants worldwide, stops the body from processing leucine, isoleucine and valine (MedlinePlus). Treatment includes dietary leucine restriction and BCAA-free medical foods (GeneReviews); people with MSUD should follow their care team's diet, not lists like this one.

Kidney disease, allergies and levodopa. Older people with severe kidney disease who are not on dialysis may need to limit protein (PROT-AGE); ask your doctor first. The FDA's major food allergens are milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. Leucine is one of the amino acids that compete with the Parkinson's drug levodopa for entry into the brain, though normal dietary swings mattered little in a study of 11 patients; if you take levodopa, ask your clinician about protein timing.

What research does not establish

• That a food's leucine content alone predicts its effect on muscle.
• That whole-food meals need a fixed amount of leucine, such as 2.5 or 3 g.
• That higher-leucine foods build more muscle over months when total protein is matched.
• That every USDA value matches the food you eat; some values were calculated rather than measured.

How we reviewed the evidence

On October 25, 2026, we fetched 28 USDA FoodData Central records (22 in the table, 1 in the text). We searched PubMed for studies of whole foods or protein sources that measured MPS (29 records, all screened), studies measuring HMB in foods (14, none relevant), dietary leucine intake (9, all screened) and retractions of cited papers (none). We read six full texts, the other abstracts, and BfR, ODS, Health Canada, MedlinePlus, GeneReviews and FDA pages. The WHO and U.S. reports did not open; their leucine values come from FAO's 2013 report and peer-reviewed papers. Animal studies were background only. Vinatura did not run any trials or food analyses.

Vinatura Research Perspective

We asked which foods give the most leucine per portion, whether animal and plant foods differ, and whether the per-meal threshold holds for whole foods. The earlier version of this page ranked foods per 100 g, listed grapefruit (0.015 g per 100 g) as a source, and did not say whether foods were raw or cooked; its beef figure (2.65 g) differs from USDA's 2.04 g for a broiled 90% lean patty. In USDA data, meat and fish protein has about the same leucine share as soybean and bean protein; the larger gap is protein per serving. Threshold figures come mostly from protein drinks, and in the whole-egg and 12-week milk and whey trials, leucine content alone did not predict results. Pork, egg or beef producer groups funded or collaborated on some food trials in the table.

Our assessment: USDA data are a sound basis for ranking common foods. Evidence that protein amount matters is consistent; evidence that leucine share matters once protein is matched is limited and short-term; evidence for a fixed per-meal leucine amount from whole foods is weak. Long-term trials in older adults comparing foods of different leucine share at matched protein, or an updated requirement for older adults, would change this view.

Where this ingredient appears in Vinatura products

HMB Leucine Creatine Powder with Vitamin D3 - Lemonade contains 3 g of L-leucine per serving (one scoop; 30 servings), with 5 g creatine monohydrate, 3 g calcium HMB (myHMB®) providing 390 mg calcium, and 40 mcg (1,600 IU) vitamin D3. It is NSF Contents Certified (per product page). The studies above did not test this product.

Frequently asked questions

What foods are high in leucine? Protein-rich foods. Per 100 g, dried spirulina, Parmesan and pumpkin seeds rank highest, but per serving, cottage cheese, cooked soybeans, chicken, lean beef, salmon and tuna give the most (about 1.3 to 2.9 g).

What is a good natural plant source of leucine? Cooked soybeans (2.3 g per cup), then lentils and black beans (about 1.2 to 1.3 g per cup).

How much leucine do adults need a day? WHO/FAO/UNU puts the adult requirement at 39 mg per kg of body weight a day; the U.S. EAR is 34 mg/kg and the RDA 42 mg/kg, or about 2.4 to 2.9 g at 70 kg.

References

• U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, SR Legacy food records (FDC IDs 168917, 169704, 170148, 170495, 170556, 170567, 170848, 171077, 171265, 171477, 172421, 172430, 172448, 173417, 173424, 173709, 173757, 173904, 174031, 174271, 174673, 175168, 175237). Last updated April 2019. Accessed October 25, 2026. fdc.nal.usda.gov
• Gorissen SHM, et al. Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids. 2018;50(12):1685–1695. doi:10.1007/s00726-018-2640-5
• Pinckaers PJM, et al. The muscle protein synthetic response following corn protein ingestion does not differ from milk protein in healthy, young adults. Amino Acids. 2024;56(1):8. doi:10.1007/s00726-023-03377-z
• Joint WHO/FAO/UNU Expert Consultation. Protein and amino acid requirements in human nutrition. World Health Organ Tech Rep Ser. 2007;(935):1–265. PubMed
• Food and Agriculture Organization of the United Nations. Dietary protein quality evaluation in human nutrition: report of an FAO Expert Consultation. FAO Food and Nutrition Paper 92. Rome: FAO; 2013. Table 3. fao.org
• Millward DJ. Amino acid scoring patterns for protein quality assessment. Br J Nutr. 2012;108(Suppl 2):S31–S43. doi:10.1017/S0007114512002462
• Health Canada. Dietary Reference Intakes tables: reference values for macronutrients (2005). Modified November 19, 2025. canada.ca
• Norton LE, et al. The leucine content of a complete meal directs peak activation but not duration of skeletal muscle protein synthesis and mammalian target of rapamycin signaling in rats. J Nutr. 2009;139(6):1103–1109. doi:10.3945/jn.108.103853
• Katsanos CS, et al. A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. Am J Physiol Endocrinol Metab. 2006;291(2):E381–E387. doi:10.1152/ajpendo.00488.2005
• Churchward-Venne TA, et al. Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial. Am J Clin Nutr. 2014;99(2):276–286. doi:10.3945/ajcn.113.068775
• Moore DR, et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. J Gerontol A Biol Sci Med Sci. 2015;70(1):57–62. doi:10.1093/gerona/glu103
• Jäger R, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8
• Zaromskyte G, et al. Evaluating the leucine trigger hypothesis to explain the post-prandial regulation of muscle protein synthesis in young and older adults: a systematic review. Front Nutr. 2021;8:685165. doi:10.3389/fnut.2021.685165
• Wilkinson K, et al. Association of postprandial postexercise muscle protein synthesis rates with dietary leucine: a systematic review. Physiol Rep. 2023;11(15):e15775. doi:10.14814/phy2.15775
• Symons TB, et al. A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects. J Am Diet Assoc. 2009;109(9):1582–1586. doi:10.1016/j.jada.2009.06.369
• Burd NA, et al. Differences in postprandial protein handling after beef compared with milk ingestion during postexercise recovery: a randomized controlled trial. Am J Clin Nutr. 2015;102(4):828–836. doi:10.3945/ajcn.114.103184
• van Vliet S, et al. Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men. Am J Clin Nutr. 2017;106(6):1401–1412. doi:10.3945/ajcn.117.159855
• Gorissen SH, et al. Ingestion of wheat protein increases in vivo muscle protein synthesis rates in healthy older men in a randomized trial. J Nutr. 2016;146(9):1651–1659. doi:10.3945/jn.116.231340
• Pinckaers PJ, et al. Higher muscle protein synthesis rates following ingestion of an omnivorous meal compared with an isocaloric and isonitrogenous vegan meal in healthy, older adults. J Nutr. 2024;154(7):2120–2132. doi:10.1016/j.tjnut.2023.11.004
• ClinicalTrials.gov. NCT05151887: The impact of a whole-food animal-based versus plant-based protein rich meal on muscle protein synthesis. Accessed October 25, 2026. clinicaltrials.gov
• Connolly G, et al. Effects of consuming ounce-equivalent portions of animal- vs. plant-based protein foods, as defined by the Dietary Guidelines for Americans on essential amino acids bioavailability in young and older adults: two cross-over randomized controlled trials. Nutrients. 2023;15(13):2870. doi:10.3390/nu15132870
• Domić J, et al. A well-balanced vegan diet does not compromise daily mixed muscle protein synthesis rates when compared with an omnivorous diet in active older adults: a randomized controlled cross-over trial. J Nutr. 2025;155(4):1141–1150. doi:10.1016/j.tjnut.2024.12.019
• Askow AT, et al. Impact of vegan diets on resistance exercise-mediated myofibrillar protein synthesis in healthy young males and females: a randomized controlled trial. Med Sci Sports Exerc. 2025;57(9):1923–1934. doi:10.1249/MSS.0000000000003725
• ClinicalTrials.gov. NCT04232254: Defining beef and meal frequency as key components of a healthy eating pattern for muscle health and wellbeing. Accessed October 25, 2026. clinicaltrials.gov
• Hevia-Larraín V, et al. High-protein plant-based diet versus a protein-matched omnivorous diet to support resistance training adaptations: a comparison between habitual vegans and omnivores. Sports Med. 2021;51(6):1317–1330. doi:10.1007/s40279-021-01434-9
• Hamarsland H, et al. No difference between spray dried milk and native whey supplementation with strength training. Med Sci Sports Exerc. 2019;51(1):75–83. doi:10.1249/MSS.0000000000001758
• Domić J, et al. A self-selected vegan diet reduces skeletal muscle mass in healthy older adults: a randomized controlled trial. Am J Clin Nutr. 2026;124(3):101416. doi:10.1016/j.ajcnut.2026.101416
• Szwiega S, et al. Dietary leucine requirement of older men and women is higher than current recommendations. Am J Clin Nutr. 2021;113(2):410–419. doi:10.1093/ajcn/nqaa323
• Weiler M, Hertzler SR, Dvoretskiy S. Is it time to reconsider the U.S. recommendations for dietary protein and amino acid intake? Nutrients. 2023;15(4):838. doi:10.3390/nu15040838
• Phillips SM, Paddon-Jones D, Layman DK. Optimizing adult protein intake during catabolic health conditions. Adv Nutr. 2020;11(4):S1058–S1069. doi:10.1093/advances/nmaa047
• German Federal Institute for Risk Assessment (BfR). Food supplements: high intake of isolated branched-chain amino acids can lead to health impairments. BfR Opinion No. 052/2019. December 20, 2019. bfr.bund.de
• NIH Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals. Accessed October 25, 2026. ods.od.nih.gov
• Wilson JM, et al. International Society of Sports Nutrition position stand: beta-hydroxy-beta-methylbutyrate (HMB). J Int Soc Sports Nutr. 2013;10(1):6. doi:10.1186/1550-2783-10-6
• Elango R, et al. Determination of the tolerable upper intake level of leucine in acute dietary studies in young men. Am J Clin Nutr. 2012;96(4):759–767. doi:10.3945/ajcn.111.024471
• Rasmussen B, et al. Determination of the safety of leucine supplementation in healthy elderly men. Amino Acids. 2016;48(7):1707–1716. doi:10.1007/s00726-016-2241-0
• MedlinePlus Genetics (National Library of Medicine). Maple syrup urine disease. Last updated July 1, 2017. medlineplus.gov
• Strauss KA, Puffenberger EG, Carson VJ. Maple syrup urine disease. GeneReviews. Last update April 23, 2020. ncbi.nlm.nih.gov
• Bauer J, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013;14(8):542–559. doi:10.1016/j.jamda.2013.05.021
• U.S. Food and Drug Administration. Food Allergies: What You Need to Know. Content current as of August 16, 2024. fda.gov
• Nutt JG, et al. Influence of fluctuations of plasma large neutral amino acids with normal diets on the clinical response to levodopa. J Neurol Neurosurg Psychiatry. 1989;52(4):481–487. doi:10.1136/jnnp.52.4.481

Editorial note: This article reviews published research for educational purposes. It does not establish the effects or safety of any specific supplement, including Vinatura products, and is not medical advice. Written by Vinatura Editorial Team. Last reviewed October 2026.