Researchers R. Rajendram & team, in their text, ‘Branched Chain Amino Acids in Clinical Nutrition (https://bit.ly/3bxRUZH), suggests that, like essential amino acids, the human body must consume approximately 40, 20, and 19 mg/kg/day of leucine, valine, and isoleucine, respectively. Collectively, this amounts in total to approximately 5.5 g/day for a 70 kg adult. The best sources of these amino acids are red meat or dairy products. However, vegans can consume sufficient amounts to meet their needs by consuming soy protein and other vegetarian sources. In the typical Western diet, approximately 20 % of all dietary protein consists of the three BCAAs, making deficiency an exceptionally rare occurrence.

One such study was conducted by the Study and Research of Aerospace Medicine on wrestlers (who weighed about 150 lbs) who were on a calorie-deficit diet and were taking 52 grams of BCAA per day. The study found that wrestlers who were supplemented with BCAA were able to preserve more muscle mass. The reason BCAA supplementation helped them preserve lean muscle mass was their meagre amount of protein intake during that research study. They were taking only 80 grams of protein per day. For a 150-pound wrestler, 80-gram protein was not even half of what he was supposed to take according to his body composition. So, BCAA supplementation is only helpful when the diet is restricted, and protein intake is inadequate. According to some researchers, people who train several hours a day might get some benefit from the BCAA supplement, but the evidence is not conclusive. Most people who train just 1 hour daily for 5 days per week do not need a BCAA supplement. We will get all the required amino acids from our regular diet, including dairy, meat, eggs, and whey protein. 

1. The research study by Hulmi JJ and Lockwood suggests that “Branched-chain amino acids obtained through whole foods like meat, dairy, and eggs are more conducive than amino acid drinks.”
2. A recent research study by scientists at the University of Arkansas found that BCAA supplementation has no positive effect on muscle growth.
3. According to Brad Schoenfeld, Ph.D. (author of science and development of muscle hypertrophy), “BCAAs can increase muscle protein synthesis, but supplementation is suboptimal to whole protein sources as whey and more expansive as well.” 
4. A recent study on the post-exercise use of Branched-chain amino acids suggests that “it does not improve select markers of muscle damage/soreness compared to carbohydrate supplementation.” 
5. Research studies performed on aerobic exercise such as cycling or sports( soccer) found that supplementation of BCAAs may reduce neural fatigue and preserve cognition later in the activity or sport. Still, its intake should be more than 50 grams to see any noticeable effect; that is too high for an average person.  On average, a 150lbs person needs only 5 grams of BCAAs per day that he can easily get from his diet.
6. Kamal Patel, the founder of examine.com, says, ” Branched-chain amino acids are three essential amino acids that benefit muscle growth. However, supplementation is unnecessary for most people because they are at high levels, notably in animal protein”.
7. A study on 21 older men and women found that a 51g amino acid mixture trended towards but was not significantly better than a placebo at reducing muscle soreness and fatigue.
8. Mike Matthews suggests that (https://legionathletics.com/bcaa-supplement/) “a BCAA supplement is useful for preserving muscle while training in a fasted state. And in case you’re wondering why you can’t just use food, remember that food will spike your insulin levels, and you will no longer be in a fasted state. In fact, whey protein is more insulinogenic than white bread. BCAAs, on the other hand, have a smaller impact on insulin levels than food, which allows you to remain in a fasted state while you train.”
9. A 2012 study in the Journal of Nutrition Science and Vitaminology by a Swiss research team led by Beat Knechtle (https://bit.ly/2QWyxjx) investigated the effect of BCAA supplementation on skeletal muscle damage and renal function during a 100km ultra-marathon run. 28 male athletes were divided into two groups. One took 50gm amino, of which 20gm was BCAA, and the other took a placebo. However, the researchers failed to see any improvement in performance, skeletal muscle damage, or renal function in the subjects.