Leucine
Leucine is one of the nine essential amino acids and sits highest in our database at whey protein hydrolysate with 10.382 grams per 100 grams, whey protein isolate at 9.559 grams and vegan protein at 5.236 grams. Among whole foods parmesan is the richest at 4.24 grams.
Why leucine gets a page of its own
Of the nine essential amino acids this is the only one people regularly search for separately. That comes from the role leucine plays in triggering muscle protein synthesis, a subject that has run in strength training circles for twenty years. We therefore give it its own page while the other eight sit on the overview: those cannot be filled without repetition, and repetition is precisely what we avoid on this site.
The richest sources, with real values
Per 100 grams: whey protein hydrolysate 10.382 g, whey protein isolate 9.559 g, vegan protein from rice and pea 5.236 g, parmesan 4.24 g and Dutch 20+ cheese 4.028 g. The first three are powders; among whole foods parmesan and Dutch 20+ cheese lead the list, followed by low-fat grated cheese at 3.127 g. More interesting than the absolute top is the ratio to calories. Turkey breast mince at 2 percent fat delivers 2.27 g leucine for 137 kcal, while parmesan costs 411 kcal. Anyone working in a calorie deficit is better off looking at leucine per hundred kilocalories than at leucine per hundred grams.
Why we name no daily amount here
Our source data carries no target for leucine. The note points to a guideline that scales with body weight, and that is exactly why we do not print it as a single figure: a value holding for someone of 65 kilos does not hold for someone of 95. Whatever gets entered in an individual coaching schedule is a personal prescription inside supervision. That does not belong on a public page, so we do not put it there.
Leucine per meal or leucine per day
The conversation about this amino acid is rarely about a daily total and almost always about distribution. A day with 150 grams of protein from a single evening meal looks identical on paper to 150 grams spread across four moments, while practice differs. In programmes we therefore steer one protein source at every meal. That is a structural agreement you can keep in a full working week, and for this audience that is the decisive condition.
Standalone leucine or simply protein?
We sell no amino acid products and assess no brands. What is factually settled: Regulation (EU) No 432/2012 carries no authorised wording for leucine on its own, while claims do exist for protein as a whole. A complete protein source also brings the other eight essential amino acids along, plus zinc, phosphorus and often calcium. A standalone capsule does not, and we would rather make that comparison explicit than quietly skip it.
How we compile this list
We sort every row in the DCRAFT food database on the measured value per 100 grams and take the top of that list. Rows recorded per piece, per slice or per portion do not count, because a value per piece cannot be compared with a value per 100 grams. Products listed under a brand name are left out: their composition changes outside our control, and a ranking resting on it ages without us noticing. Where several products carry precisely the same value, it comes from one shared row in our source data and we name one product from that group. We set this rule out here because a ranking without a visible selection rule is an opinion rather than a measurement.
Frequently asked questions
Which foods contain the most leucine?
Whey protein hydrolysate leads at 10.382 grams per 100 grams, with whey protein isolate at 9.559 grams. Among whole foods parmesan is the richest at 4.24 grams.
How much leucine do you need per day?
Our source sets no fixed daily value and points to a guideline that scales with body weight. We therefore print no figure at all as general advice.
Which protein source supplies leucine at low calories?
Turkey breast mince at 2 percent fat supplies 2.27 grams of leucine for 137 kcal per 100 grams. Parmesan supplies more leucine, but costs 411 kcal.
Is a standalone leucine supplement worthwhile?
We make no supplement recommendations. Factually, no authorised claim exists for leucine on its own, while claims about protein as a whole do exist.
Sources
- DCRAFT food database — KILLER COACH ENGINE V2.3 workbook (accessed 26 August 2026)
- Regulation (EU) No 432/2012 (accessed 26 August 2026)
Please note: This is general information about nutrition, not medical advice. If you have symptoms or suspect a deficiency, discuss it with your doctor. We do not sell supplements and have no commercial interest in any brand.
Last updated: .
Written by Dennis, founder of Dcraft Of Fitness.