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 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 — followed by legumes, peanuts and seeds. The table below shows grams of leucine per 100 g of food; there is no 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 | Pork 3 oz / 85 g | 🟢 2.2 g | 0 | 0 | |
| 7 | Salmon 3 oz / 85 g | 🟢 2.2 g | 0 | 0 | |
| 8 | Chicken Organ Meats 3 oz / 85 g | 🟢 2.2 g | — | — | Nutrient-dense organ meat (giblets). |
| 9 | Tuna 3 oz / 85 g | 🟢 2.1 g | 0 | 0 | |
| 10 | Beef Organ Meats 3 oz / 85 g | 🟢 1.8 g | — | — | Nutrient-dense organ meat. |
| 11 | Shrimp 3 oz / 85 g | 🟡 1.7 g | — | — | |
| 12 | Peanuts 1 oz / 28 g | 🟡 1.7 g | — | — | |
| 13 | Almonds 1 oz / 28 g | 🟡 1.5 g | 0.2 | 0.1 | |
| 14 | Sunflower Seeds 1 oz / 28 g | 🟡 1.2 g | — | — | |
| 15 | Egg 1 large / 50 g | 🟡 1.1 g | — | — | |
| 16 | Chicken Breast 3 oz / 85 g | 🟡 1.1 g | — | — | |
| 17 | Brown Rice 1 cup / 195 g | ⚪ 0.2 g | 0 | 0 | Common staple. |
Table of Contents
- How to Read These Tables
- Recommended Intakes & Upper Limits
- Bioavailability & Absorption
- Cooking & Storage
- Vegetarian & Vegan Sources
- Who Needs to Pay Attention
- Data Sources & References
- Connections
- Featured Videos
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 FDA 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
Your personal target depends on age, sex and pregnancy. The Daily Value used for the %DV column above is a single label figure; the table below is the age-specific guidance.
| Reference | Adult value | Notes |
|---|---|---|
| Essential? | Yes — essential (a 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. The strongest plant sources are lentils, white and other beans, chickpeas, peanuts, pumpkin and sunflower seeds, and firm whole grains. 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 who should pay attention 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. The fix is simply adequate quality protein, not isolated leucine supplements. People with the rare metabolic disorder maple syrup urine disease must restrict BCAAs including leucine under medical supervision.
Data Sources & References
- NIH MedlinePlus — Amino acids
- Linus Pauling Institute — protein and amino acids
- PubMed — leucine, mTOR and muscle protein synthesis
- PubMed — branched-chain amino acid requirements