Amino acids explained: BCAA, EAA, and protein needs in sport

Amino acids are the building blocks your body uses to assemble all proteins — from muscle fibers to enzymes to antibodies. In marketing they show up as BCAA powders, EAA capsules, or amino acid complexes, often with big promises. What's actually established, what the DGE recommends as protein intake, and when it makes sense to think about this at all — coming up. The full overview of all micronutrients is in the pillar Micronutrients.

What amino acids are and what they're used for

There are 20 so-called proteinogenic amino acids — that is, amino acids found in proteins. Of these, 9 are essential for adults: your body can't produce them itself, so you have to get them from food. The remaining 11 the body can synthesize from other building blocks.

Amino acids are needed for a whole range of body structures and functions — as building blocks for muscle tissue, enzymes, hormones, connective tissue, hemoglobin, immune cells. With protein deficiency, the body isn't missing a single substance but the synthesis basis for all these building blocks. That's also why the DGE doesn't specify protein needs in individual amino acids but as a daily amount in grams per kilogram of body weight.

The 9 essential amino acids

Amino acid	Note
Leucine	belongs to BCAA
Isoleucine	belongs to BCAA
Valine	belongs to BCAA
Lysine	often limiting in plant diets (low in grains)
Methionine	tighter in vegetarian/vegan diets
Phenylalanine	precursor of tyrosine
Threonine	important in connective tissue proteins
Tryptophan	precursor of serotonin and melatonin (metabolism)
Histidine	essential for adults; long debated

A "complete" protein source is one that provides all 9 essential amino acids in sufficient amounts. Animal foods (meat, fish, eggs, dairy) are classically complete sources. Plant foods are often limited in a single amino acid — grains have little lysine, legumes have little methionine. Combining within the same day (rice and beans, whole-grain bread and hummus, lentils and couscous) covers that gap.

What BCAA and EAA actually mean

• BCAA (Branched-Chain Amino Acids) are three of the 9 essential amino acids with a branched side chain: leucine, isoleucine, valine. You'll find them in any protein-rich food — particularly dense in quark, chicken breast, lentils, or eggs.
• EAA (Essential Amino Acids) refers to all 9 essential amino acids. EAA is the more complete group; BCAA preparations cover only part of it.

In advertising, BCAA powders are often promoted with muscle building or recovery promises. Important: EFSA has not authorized health claims for isolated amino acids or BCAA in the sport context. Anyone who reads such promises on a product should be skeptical — that's legal gray zone or violation of the EU health-claims regulation.

What DGE recommends — and what sports science discusses

The DGE daily recommendation for adults 19–65 is 0.8 g protein per kilogram of body weight per day. At 70 kg that's about 56 g of protein — easily reached with a yogurt in the morning, a lentil meal at lunch, and fish or chicken in the evening.

Group	DGE recommendation
Adults 19–65	0.8 g/kg b.w. / day
Seniors from 65	1.0 g/kg b.w. / day
Pregnant (2nd trimester)	+7 g / day extra
Pregnant (3rd trimester)	+21 g / day extra
Breastfeeding	+23 g / day extra
Children/adolescents	0.8–0.9 g/kg b.w. / day

The older group gets more because protein utilization becomes less efficient with age (anabolic resistance). More in Micronutrients after 50.

In sports science, there's been ongoing debate about whether athletes need more protein. Current position of international sports nutrition societies (ISSN 2017): with moderate strength training 1.4–1.6 g/kg b.w.; in very intense training or diet phases up to 2.0 g/kg b.w. Important: these are not DGE-authorized values but consensus positions from sports science. The DGE itself doesn't list a separate sports add-on for recreational training.

Where to find protein in food

Complete or near-complete protein sources (all essential amino acids) in everyday life:

Food (100 g)	Protein	Note
Quark (low-fat)	~ 13 g	very high-quality protein source
Lentils (cooked)	~ 9 g	combine with grains
Chicken breast	~ 23 g	classic animal source
Salmon	~ 20 g	plus omega-3
Egg (1 piece)	~ 6 g	reference protein
Tofu	~ 16 g	complete (soy)
Skyr	~ 11 g	high protein content
Oats	~ 13 g	combine with dairy
Chickpeas (cooked)	~ 8 g	combine with grains

Soy foods (tofu, tempeh, soy drink) are one of the few plant sources that deliver all essential amino acids in sufficient amounts. Anyone eating plant-based and wanting to skip soy: legumes plus whole grains in the same day work in practice.

When amino acid supplementation can make sense — and when not

Across-the-board amino acid supplementation is unnecessary for most people. Three constellations where it becomes worth considering:

• High-intensity competitive sport with restricted energy intake, e.g., during cutting phases.
• Impaired protein absorption due to illness, surgery, or recovery — but always with medical supervision.
• Reduced gastric acid (e.g., on proton pump inhibitors), which can impair protein digestion.

What most people don't need: a BCAA shake after every workout. If you eat a protein-rich meal right after training (quark, skyr, lentils, chicken, tofu), you get the same amino acid profile — cheaper and with the accompanying nutrients real food provides.

What matters day to day

The honest summary: people who eat regularly are usually adequately supplied. A few habits make the difference:

• A protein source at every main meal — not just in the evening. The body can only effectively use a limited amount of protein per meal for synthesis.
• Plant + animal or well-combined plant sources — both work; the combination is the question, not the source.
• Quark, skyr, legumes, eggs, fish as simple building blocks that deliver complete supply without powders.

If you want to know whether your protein setup fits everyday life — or whether you fall into one of the special constellations where targeted adjustment makes sense — the free Vital-Check gives a written assessment in a few minutes. For parallel reading on fatigue topics, see Iron and tiredness and B vitamins overview.