Conditions: 103 kg · 900 kcal.
I want the working, not the result — I need to be able to redo it with different numbers.
I care about the precision as well as the value — I want to know how many figures are real.
How many significant figures are actually justified here?
165 to 227 g a day. The range the resistance-training literature supports is 1.6 to 2.2 g per kilogram, which at 103 kg is 165–227 g. At 4 kcal per gram that is 659–906 kcal, or 73–101 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.
Start with which body weight the target is calculated from, because using total weight in someone with substantial adiposity inflates the number without benefit.
High protein intakes do not damage healthy kidneys in the published evidence; existing kidney disease is a genuine exception and is a clinical question.
The underlying point is that 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.
Leucine threshold effects are documented across protein sources and explain the difference in per-serving requirements between animal and plant proteins.
Plan protein first in the day; with suppressed appetite it will not happen otherwise.
Aggregated, published test results and vendor ratings built from submitted batches. Methodology stated, dataset browsable, no listing fees.
Browse resultsThe underlying point is that plant-based patterns need somewhat higher totals and more attention to leucine content per serving to produce an equivalent response.
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.
Hydration requirements rise modestly with protein intake because urea excretion increases, which is a real effect and a small one.
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.
Healthy kidneys tolerate this fine. Diseased ones are a clinical question.
Answer first: aim for 1.6 to 2.2 grams per kilogram of reference body weight per day, distributed across three or four servings, and treat it as the first constraint on the day rather than the last.
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.
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.
Research-use compounds are not approved for human use, and no supplement substitutes for total intake.
Plant-based patterns need a higher total and more attention per serving.
This is one of the better-evidenced areas in nutrition and the disagreements are about the top of the range, not the bottom.
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.
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.
Per-meal saturation is real. One enormous serving does not do the job of three.
edited 23 Feb 2025 by kirsi_lahtinen — removed a claim I could not source
To be exact about it, 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.
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.
Targets are population estimates; individual requirements vary and there is no cheap way to measure yours.
1.6 to 2.2 g/kg of reference weight, split three or four ways. That is the answer.
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.