Beneficial effects on body weight when supplementing with branched chain amino acids have been observed in animal and human studies. Valine, leucine and isoleucine are the three branched chain amino acids that together compose approximately a third of the daily amino acid requirement in humans. They are essential amino acids and comprise 35% of the amino acids found in muscle tissue. They are involved in the regulation of protein metabolism, weight loss and body composition, and can be used as an energy source for the muscles when required.
Branched chain amino acids, or also known as BCAAs, play an important role in the regulation of energy and protein metabolism and are primarily oxidized in skeletal muscle and not in the liver. Branched chain amino acids have anabolic effects on the metabolism of protein by means of increasing rate of protein synthesis as well as decreasing rate of protein degradation in muscle. Providing muscles with extra branched chain amino acids could help protect against exercise associated muscle damage, and can also help develop more calorie burning muscle.
In a study, a diet with a higher percentage of leucine resulted in a higher level of weight loss. When combined with the leucine supplemented diet resulted in an even higher level of weight loss with participants losing more fat and retaining more lean mass.
In another study researchers examined the association between dietary branched chain amino acid intake and risk of overweight or obesity status among multi ethnic populations. The study concluded that increased dietary branched chain amino acid consumption is linked to reduced incidence of overweight or obesity status in healthy middle aged adults from Western and East Asian countries.
Around 25% of the protein found in whole food sources consists of these branched chain amino acids. The consumption of amino acid supplements differs from the consumption of proteins containing those amino acids. This is because they don’t need to be digested, and will go into the blood stream straight away.