Leucine is one of the 8 essential amino acids that humans need to obtain from dietary sources. Human body cannot produce this amino acid.

Evidences from several studies, mostly conducted on rats, indicate that leucine is involved in protein synthesis in skeletal muscles, and can inhibit protein degradation in skeletal muscles and liver. It is also an important component of hemoglobin.

Leucine rich food sources include legumes, such as soy beans and cowpea, and animal products, such as cheese, beef and fish. Below is a list of select food sources which contain high and low leucine content with estimates of their leucine content. The foods are ordered from high to low content.

High Leucine Foods

Leucine food sourcesLeucine content (g/ 100g food)
Sesame seed flour, low fat 3.84
Soybeans, mature seeds, raw
2.97
Cheese, swiss 2.96
Cheese, parmesan 2.75
lentils, raw
2.03
cowpea, catjang, mature seeds, raw
1.83
Beef, round, top round, separable lean and fat, trimmed to 1/8" fat, select, raw
1.76
Beef, top sirloin, separable lean only, trimmed to 1/8" fat, choice, raw
1.74
Peanuts, all types, raw
1.67
Salami, Italian, pork
1.63
Fish, salmon, pink, raw
1.62
Crustaceans, shrimp, mixed species, raw
1.61
Chicken, broilers or fryers, thigh, meat only, raw
1.48
Nuts, almonds
1.47
Egg, yolk, raw, fresh
1.40
Chickpeas (garbanzo beans, bengal gram), mature seeds, raw
1.37
Seeds, sesame butter, tahini, from raw and stone ground kernels
1.36
Chicken, broilers or fryers, wing, meat and skin, raw
1.29
flax seed, raw
1.24
Nuts, walnuts, english
1.17
Egg, whole, raw, fresh
1.09
Egg, white, raw, fresh
1.02
Sausage, Italian, pork, raw
0.96

 

There are foods which don't contain much leucine. Examples of such low leucine foods are vegetables, such as kale, cauliflower, spinach; and fruits such as mango, papaya, apple. An extended list of them can be found below.

Low Leucine Foods

 Food type Leucine content (g /100g food)
Milk, sheep, fluid
0.59
Yoghurt, plain, low fat 0.53
Pork, fresh, separable fat, raw
0.40
Hummus
0.35
Yoghurt, plain, whole milk 0.35
Peas, green, raw 0.32
Milk, goat, fluid
0.31
Milk, whole, 3.25% milkfat
0.27
Soy milk, fluid
0.24
Spinach, raw 0.22
Kale, raw 0.20
Cauliflower, green, raw 0.17
asparagus
0.13
Snap beans, green, raw
0.11
Milk, human, mature, fluid
0.10
Mango, raw 0.05
Papaya, raw 0.02
Apple, raw 0.01


Leucine related content:
Recommended Daily allowances (RDA) of leucine for adults, kids, pregnant and lactating women

Protein related content:
Food sources of protein: animal and vegetable protein sources and content.
Protein requirement: for kids, adults and pregnant and lactating women.
Soybean/tofu: nutritional value and health benefits
Essential and non essential amino acids: Definitions and Functions
L-Arginine: Food Sources, Health Benefits and Side Effects

Sources

Garlick, P. J. The Role of Leucine in the Regulation of Protein Metabolism. J. Nutr. 135:1553S-1556S, 2005.

Data source: USDA National Nutrient Database for Standard Reference, Release 19 (2006).