The specifics, since they change the answer: 68 kg · 800 kcal.
I would like the arithmetic checked rather than the conclusion asserted.
I have deliberately not used an online calculator because I want to be able to check the result.
Can someone show the working rather than just the answer?
109 to 150 g a day. The range the resistance-training literature supports is 1.6 to 2.2 g per kilogram, which at 68 kg is 109–150 g. At 4 kcal per gram that is 435–598 kcal, or 54–75 per cent of a 800 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.
Plant-based patterns need somewhat higher totals and more attention to leucine content per serving to produce an equivalent response.
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.
| Method | Measures | Sensitive to | Least significant change |
|---|---|---|---|
| DEXA | Three-compartment by attenuation | Hydration, positioning | ~2–3 % regional lean |
| BIA (consumer) | Impedance, modelled | Hydration, food, temperature | Not usable at this timescale |
| Air displacement | Two-compartment by density | Lung volume, hair, clothing | ~1–2 % fat mass |
| Tape and scale | Circumference, mass | Technique | Surprisingly usable as a trend |
More usefully, 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.
Systematic reviews of high-protein intake in people with normal renal function have not found evidence of harm to kidney function.
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.
edited 14 Jun 2026 by sian_llewellyn — fixed an arithmetic slip in the third paragraph
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
Shop standardsIn practice, protein is also the most satiating macronutrient per kilocalorie, which makes hitting the target easier than it sounds once it is prioritised.
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.
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.
Leucine threshold effects are documented across protein sources and explain the difference in per-serving requirements between animal and plant proteins.
Nothing here is dietetic or medical advice.
Healthy kidneys tolerate this fine. Diseased ones are a clinical question.
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.