The case in front of me: 81 kg · 900 kcal.
Please show the division. I want to check my own against yours.
I would like the general form as well as the specific number, so I can apply it again.
How many significant figures are actually justified here?
130 to 178 g a day. The range the resistance-training literature supports is 1.6 to 2.2 g per kilogram, which at 81 kg is 130–178 g. At 4 kcal per gram that is 518–713 kcal, or 58–79 per cent of a 900 intake — which is why protein has to be planned first at this energy level rather than fitted in afterwards. Split it across three or four servings; roughly 0.4 g/kg per meal saturates the synthetic response and the surplus in one large serving does not carry over.
The relevant physiology is the per-meal saturation of the synthetic response, which is why one large serving does not substitute for three moderate ones.
Hydration requirements rise modestly with protein intake because urea excretion increases, which is a real effect and a small one.
High protein intakes do not damage healthy kidneys in the published evidence; existing kidney disease is a genuine exception and is a clinical question.
Stable-isotope feeding studies establish the per-meal saturation of muscle protein synthesis at around 0.4 g/kg in young adults and higher in older ones.
Targets are population estimates; individual requirements vary and there is no cheap way to measure yours.
Healthy kidneys tolerate this fine. Diseased ones are a clinical question.
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
Shop standardsMechanically, this is one of the better-evidenced areas in nutrition and the disagreements are about the top of the range, not the bottom.
The leucine threshold for triggering the response is around two and a half to three grams per meal. Thirty grams of most animal protein reaches it; thirty grams of many plant proteins does not, which is why plant-based targets run higher.
On the detail: appetite suppression makes protein-rich foods harder to eat because they are satiating. Liquid protein and leaner, less voluminous sources are the usual practical workaround.
Leucine threshold effects are documented across protein sources and explain the difference in per-serving requirements between animal and plant proteins.
Plant-based patterns need a higher total and more attention per serving.
To be exact about it, protein is also the most satiating macronutrient per kilocalorie, which makes hitting the target easier than it sounds once it is prioritised.
Per meal, roughly 0.4 grams per kilogram saturates the synthetic response in most adults, which is about 30 to 40 grams for a typical person. Beyond that the surplus is oxidised or used for other purposes rather than adding to synthesis.
Use reference or adjusted body weight rather than total weight where adiposity is substantial: a common approach is ideal body weight plus a quarter of the excess, which avoids targets that no one could eat.
Research-use compounds are not approved for human use, and no supplement substitutes for total intake.
1.6 to 2.2 g/kg of reference weight, split three or four ways. That is the answer.
edited 14 Jul 2025 by nynke_dekker — added the citation requested in comments
It helps to be literal here: plant-based patterns need somewhat higher totals and more attention to leucine content per serving to produce an equivalent response.
Older adults need more per meal to overcome anabolic resistance, with 1.2 to 1.5 g/kg daily commonly quoted for maintenance and more in a deficit.
Meta-analytic estimates place the plateau of the dose-response for lean-mass retention with resistance training around 1.6 g/kg, with a confidence interval extending to about 2.2.
Nothing here is dietetic or medical advice.
Per-meal saturation is real. One enormous serving does not do the job of three.
Start with which body weight the target is calculated from, because using total weight in someone with substantial adiposity inflates the number without benefit.
A practical construction: 30 to 40 grams at each of three meals plus a 20 to 30 gram snack covers most targets without any protein powder at all.
The caveat is that anyone with chronic kidney disease has a genuinely different protein calculation and needs it done by a clinician.
Plan protein first in the day; with suppressed appetite it will not happen otherwise.
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.