BCAA (Branched-Chain Amino Acids): Requirements, Indian Foods and Trial Evidence

The branched-chain amino acids, or BCAA, are leucine, isoleucine and valine. They are three of the nine amino acids your body cannot make, and they are present in every protein food you eat. An adult needs about 39 mg of leucine, 20 mg of isoleucine and 26 mg of valine per kg of body weight a day, and a glass of cow's milk supplies about 1.9 g of the three together. Sold alone as a powder, they have performed worse in trials than the complete protein they come from. This entry belongs to the supplements section of the handbook.

What are branched-chain amino acids?

They are three essential amino acids grouped by a shared feature of their structure, a side chain that forks. Leucine draws most of the attention because, besides being a building block, it helps to switch on the cell's machinery for making protein. The catch, set out in a 2017 review in the Journal of the International Society of Sports Nutrition, is that new muscle protein requires all nine essential amino acids, along with the eleven the body can make, to be present in adequate amounts.

A BCAA powder contains only the three. Most trials have used them in a ratio of 2 parts leucine to 1 of isoleucine and 1 of valine: seven of the nine studies in one meta-analysis did so, and the other two used 3 to 1 to 2.

How much leucine, isoleucine and valine do you need?

An adult needs 39 mg of leucine, 20 mg of isoleucine and 26 mg of valine for each kg of body weight a day, 85 mg per kg in all. Those are the WHO/FAO/UNU 2007 values as printed, with amendments, in the FAO's 2013 report on protein quality. For a 65 kg man the total comes to about 5.5 g a day, and for a 55 kg woman about 4.7 g. Children need more for their size.

These amounts are part of your protein requirement, not an extra on top of it. ICMR-NIN's 2020 report sets the adult protein allowance at 0.83 g per kg a day, which is 54.0 g for a 65 kg man and 45.7 g for a 55 kg woman. The protein calculator gives your own figure.

The Indian position: ICMR-NIN's pattern and its caution on BCAA

ICMR-NIN expresses the need as a pattern: each gram of dietary protein should carry 59 mg of leucine, 30 mg of isoleucine and 39 mg of valine. Its Dietary Guidelines for Indians, 2024, then test the recommended plate against that pattern. The vegetarian My Plate for the Day supplies 84.0 mg of leucine, 41.2 mg of isoleucine and 51.3 mg of valine per gram of protein, and the non-vegetarian plate 86.6, 42.8 and 53.4 mg. Both clear the pattern by a wide margin, wider than the one for lysine, which is covered in the entry on lysine.

The same guidelines are the only Indian document read for this entry that mentions BCAA by name, and the mention is a warning. They note that whey protein is rich in BCAA, and that recent evidence suggests BCAA may increase the risk of certain non-communicable diseases. They advise readers to avoid protein supplements for building muscle, and report that protein intakes above about 1.6 g per kg a day add nothing further to the muscle gained from resistance training.

BCAA in Indian foods: dal, milk, paneer and egg

Every protein food carries the three together. In the Indian Food Composition Tables 2017, leucine, isoleucine and valine add up to 23.3 g in every 100 g of cow's milk protein, 20.2 g in paneer protein, 17.2 g in moong dal protein and 14.5 g in toor dal protein. The table turns those shares into household portions by raw weight.

The egg row needs a note. IFCT's published file gives the protein in a hen's egg, 13.28 g per 100 g, but the page carrying its essential amino acids could not be read, so the leucine figure applies the 7.0 per cent share measured in egg protein by a 2018 laboratory comparison. Pages for moong dal, the milk and dairy group and the hen's egg give each food's full panel, and the moong dal chilla recipe uses a katori's worth.

What do trials show for BCAA against complete protein?

They show a smaller effect. In the trial most often quoted in favour of BCAA, ten young men who lifted regularly drank either 5.6 g of BCAA or a placebo straight after a leg workout. Muscle protein synthesis over the next four hours was 22 per cent higher with BCAA. The authors themselves pointed out that this was about 50 per cent less than the response earlier measured with a serving of whey protein holding a similar amount of BCAA. The study, published in Frontiers in Physiology in 2017, was supported by GlaxoSmithKline, which supplied the drinks.

The 2017 review mentioned above reached a blunter conclusion. Its author found no study at that time in which muscle protein synthesis had been measured after BCAA taken by mouth alone, and two in which BCAA were given into a vein: in both, muscle protein synthesis fell, and so did breakdown. He concluded that BCAA supplements alone do not promote muscle anabolism. He listed no funding for the paper, and declared grants or fees from a beef industry programme and three food companies, and shares in an amino acid business.

The ISSN's position stand on protein describes what does work in trials: 20 to 40 g of high-quality protein in a sitting, or 0.25 g per kg of body weight, containing 700 to 3,000 mg of leucine together with a balanced array of the essential amino acids. It adds that supplementation should not be with leucine alone. The stand states that no funding was provided, and several of its authors declare ties to companies that sell protein.

Do BCAA reduce muscle soreness?

Perhaps slightly, and only when compared with no protein at all. A 2021 meta-analysis in Nutrients pooled nine trials in trained men aged 18 to 25. BCAA lowered creatine kinase, a blood marker of muscle damage, for up to 48 hours after resistance exercise, and lowered reported soreness only within the first 24 hours. A second marker, lactate dehydrogenase, did not change. The control groups took a non-protein placebo or nothing, so the result does not show that BCAA beat a glass of milk or a katori of dal after training.

Who gains nothing from a BCAA supplement?

Anyone who already eats enough protein, which describes most of the people who buy it. If your day includes dal, milk or curd, paneer, egg, fish or meat in ordinary amounts, you take in about twice the requirement for all three amino acids before any powder, as the worked example below shows. A protein powder is in the same position, since whey is itself rich in BCAA; the article on whether you need protein powder deals with that choice.

A worked example: a vegetarian lifter in Hyderabad

This is an illustrative case and not a real person. Take a 24-year-old lacto-vegetarian man in Hyderabad who weighs 65 kg, lifts five days a week and has been told at the gym to add a BCAA drink. On a usual day he has two glasses of milk or curd, two katoris of moong dal, rice from 150 g of raw grain, rotis from 100 g of atta and 50 g of paneer.

The sums use raw-food values, count curd as milk and ignore digestibility, so treat them as an order of magnitude and not a measured intake.

What do FSSAI's rules allow for BCAA products?

FSSAI permits them as ingredients. Schedule II of the health supplement and nutraceutical regulations lists L-leucine, L-isoleucine and L-valine among the essential amino acids that a health supplement may contain, with the hydrochlorides of leucine and isoleucine. The schedule gives no amount for any amino acid. The regulations say only that added nutrients shall not exceed the recommended daily allowance specified by ICMR, and that Codex standards apply where ICMR has specified none. Health supplements are meant for people above the age of five years.

Every pack must carry the words HEALTH SUPPLEMENT, the amount of each nutrient, the warning NOT FOR MEDICINAL USE written prominently, the words Not to exceed the recommended daily usage, a statement that it is not a substitute for a varied diet, and a direction to store it out of reach of children. A product positioned as food for sportspersons must also say FOR SPORTSPERSON ONLY, that it is recommended under medical advice, that it is not a sole source of nutrition, and that it is to be used with a training regime. No label may claim to prevent, treat or cure a disease.

Common mistakes and myths about BCAA

The first mistake is paying twice: buying BCAA to take alongside a whey powder that, in the 2018 laboratory comparison, was already 11.0 per cent leucine. The second is drinking BCAA in place of a meal after training, which removes the other amino acids the muscle is waiting for. The third is reading soreness trials, run against a non-protein placebo, as proof of muscle growth.

Side effects, safety and when to see a doctor

The trials read for this entry lasted hours or days and studied healthy young men, so they say little about long-term use. Two signals deserve respect. In one infusion study, raising the three BCAA in the blood lowered the concentrations of the other essential amino acids. And ICMR-NIN's 2024 guidelines record a possible link between BCAA and non-communicable disease risk, and warn that high protein intakes may worsen kidney function in people who already have kidney disease. The ISSN stand notes that BCAA take part in blood glucose and insulin regulation.

Do not take BCAA without medical advice if you have kidney or liver disease, diabetes under treatment, or an inherited disorder of amino acid metabolism, if you are pregnant or breastfeeding, or if you take regular prescription medicines. A trainer's suggestion is not a reason to give them to a teenager. See a doctor about unexplained loss of muscle or weight, or soreness that does not settle within a few days. BCAA are not a treatment for any condition.

NNWA courses that cover amino acids and supplements

Amino acid products are examined in NNWA's Sports Nutrition and Dietary Supplements and Nutraceuticals courses. NNWA is a private skill academy in Kolkata whose teaching is online, in English and Hindi. Its learners are prepared to coach healthy people and to pass medical cases to a doctor, and no course it offers is a degree or a dietitian qualification.