Isoleucine

Isoleucine is one of the nine essential amino acids, meaning the body cannot produce it and it must be obtained from the diet. It is a branched-chain amino acid (BCAA) and is found naturally in protein-rich foods such as meat, poultry, fish, eggs, dairy products, and legumes. It can also be produced industrially through fermentation processes.

Isoleucine is primarily used as a nutritional supplement, particularly in sports nutrition products, to aid muscle recovery and energy production. It is sometimes added to foods and beverages marketed for their health benefits or as part of a balanced diet. It functions as a source of essential amino acids.

Isoleucine is not a food additive and does not have an E-number. It is an amino acid that is naturally present in many foods and is essential for human health. The UK's Food Standards Agency (FSA) and Food Standards Scotland (FSS) do not regulate isoleucine as a food additive. EFSA has evaluated amino acids in the context of food fortification and nutritional claims, but typically does not set specific ADIs for naturally occurring essential amino acids. Evidence suggests BCAAs like isoleucine play a role in muscle protein synthesis and energy metabolism, but claims about significant performance enhancement or disease prevention at typical dietary intakes require more robust scientific backing.