Leucine: Food Sources & Daily Intake
Leucine is one of the three branched-chain amino acids (BCAAs) and the single most important dietary signal for building and repairing muscle — it flips on the body’s main muscle-growth switch (the mechanistic target of rapamycin (mTOR) pathway). Because it is essential, the body cannot make it, so it has to come from food. The richest sources are concentrated animal proteins — hard cheeses, meat, fish, eggs — along with pumpkin seeds, peanuts and other seeds; legumes such as lentils and beans also supply it. The table below shows grams of leucine per 100 g of food; there is no U.S. Food and Drug Administration (FDA) Daily Value for individual amino acids, so amounts are absolute.
| Leucine: Food Sources & Daily Intake | |||||
|---|---|---|---|---|---|
| Rank | Food (serving) | Per 100 g | Glucose | Fructose | Notes |
| 1 | Parmesan Cheese 1 oz / 28 g | 🟢 3.5 g | — | — | Concentrated protein. |
| 2 | Cheddar Cheese 1 oz / 28 g | 🟢 2.4 g | 0 | 0 | |
| 3 | Beef Meat 3 oz / 85 g | 🟢 2.4 g | 0 | 0 | |
| 4 | Pumpkin Seeds 1 oz / 28 g | 🟢 2.4 g | 0.1 | 0.1 | |
| 5 | Pork Organ Meats 3 oz / 85 g | 🟢 2.3 g | — | — | Nutrient-dense organ meat. |
| 6 | Chicken Breast 3 oz / 85 g | 🟢 2.3 g | 0 | 0 | |
| 7 | Pork 3 oz / 85 g | 🟢 2.2 g | 0 | 0 | |
| 8 | Salmon 3 oz / 85 g | 🟢 2.2 g | 0 | 0 | |
| 9 | Tuna 3 oz / 85 g | 🟢 2.1 g | 0 | 0 | |
| 10 | Shrimp 3 oz / 85 g | 🟢 1.9 g | 0 | 0 | |
| 11 | Peanuts 1 oz / 28 g | 🟡 1.7 g | — | — | |
| 12 | Almonds 1 oz / 28 g | 🟡 1.5 g | 0.2 | 0.1 | |
| 13 | Sunflower Seeds 1 oz / 28 g | 🟡 1.2 g | — | — | |
| 14 | Egg 1 large / 50 g | 🟡 1.1 g | — | — | |
| 15 | Chicken Organ Meats 3 oz / 85 g | 🟡 0.9 g | 0 | 0 | Nutrient-dense organ meat (giblets). |
| 16 | Brown Rice 1 cup / 195 g | ⚪ 0.2 g | 0 | 0 | Common staple. |
Table of Contents
How to Read These Tables
- Essential amino acid. Your body cannot synthesize leucine, so a regular dietary supply matters. The nine essential amino acids must come from food; the other eleven the body can build itself.
- Grams per 100 g, not %DV. There is no U.S. Food and Drug Administration Daily Value for individual amino acids, so this table reports the absolute grams per 100 g of food and ranks foods by that. A typical serving is shown beside each food.
- Complete vs incomplete protein. Animal foods are “complete” — they carry all the essential amino acids in good proportion. Most single plant foods are lower in one or two; eating a variety of legumes, grains, nuts and seeds across the day covers the gaps.
Recommended Intakes & Upper Limits
Leucine has no Daily Value: the U.S. food-label rules (21 CFR 101.9) set none for it, and the green and yellow marks in the food table above only rank each food against the richest food listed. The table below summarizes its status.
| Reference | Adult value | Notes |
|---|---|---|
| Essential? | Yes — essential (a branched-chain amino acid (BCAA)) | The body cannot make it; it must come from food. |
| Adult requirement | 39 mg/kg/day | WHO/FAO/UNU 2007 estimate. |
| ≈ for a 70 kg adult | ~2.7 g/day | Easily met by a normal protein intake (~0.8 g protein/kg). |
| Richest in | Animal protein & legumes | Cheese, meat, fish, eggs, then beans, peanuts, seeds. |
Bioavailability & Absorption
Leucine from food is well absorbed as part of dietary protein. What matters most is total protein quality and quantity: animal proteins (meat, fish, eggs, dairy) are complete and leucine-dense, while plant proteins are usually a little lower in leucine and benefit from variety. Spreading protein across meals — roughly 20–40 g of quality protein per meal, supplying ~2–3 g leucine — is the practical way to keep muscle-building signaling switched on through the day.
Cooking & Storage
Amino acids are stable to ordinary cooking — leucine is not destroyed by normal heat, and cooking actually makes protein easier to digest. Very high, prolonged dry heat (charring) can damage some heat-sensitive amino acids like lysine, but leucine is robust. No special handling is needed.
Vegetarian & Vegan Sources
Plant-based eaters can get plenty of leucine, but it takes a little planning because plant proteins are less leucine-dense than animal ones. Per 100 g, the richest plant foods in the table above are pumpkin seeds (2.4 g), peanuts (1.7 g), almonds (1.5 g) and sunflower seeds (1.2 g); lentils, white and other beans, chickpeas and whole grains also supply leucine. Eating a variety across the day (legumes + grains + seeds) supplies all the essential amino acids; total protein simply needs to be a bit higher than for omnivores to reach the same leucine.
Who Needs to Pay Attention
Outright leucine deficiency is rare in anyone eating enough total protein. The groups most likely to fall short are those with low overall protein intake — some older adults (who need more protein per kilogram to maintain muscle), people recovering from illness or surgery, and very-low-calorie dieters. In these groups the shortfall is in total quality protein, which carries leucine with it, rather than in leucine alone. People with the rare metabolic disorder maple syrup urine disease are treated with a diet that restricts branched-chain amino acids including leucine, under medical supervision.