BCAA vs EAA (Essential Amino Acids)

Per NIH ODS, up to 20 g/day of BCAA supplements in divided doses appears to be safe, and the fact sheet lists no known adverse effects. For leucine alone, ODS reports that studies suggest an upper safe limit of intake of 500 mg/kg per day in healthy young and elderly men — about 38 g/day for a man weighing 75 kg (165 lb). — per NIH Office of Dietary Supplements; not medical advice.

The BCAAs — leucine, isoleucine, and valine — make up approximately 25% of the amino acids in foods containing complete proteins (those with all essential amino acids), per the NIH Office of Dietary Supplements; most of those foods are animal products such as meat, poultry, fish, eggs, and milk. ODS adds that consuming protein powders made from complete proteins, "especially whey, which has more leucine than either casein or soy," automatically increases BCAA consumption. ODS does not give per-food BCAA gram amounts in this fact sheet.