It is the most-typed question in nutrition and the worst answered, because two different figures are in circulation and almost nobody explains that they answer different questions.
The official figure: 0.8 g per kilo
The public recommendation for a healthy adult is 0.8 grams of protein per kilo of body weight per day. For seventy kilos that is 56 grams. The federal dietary guidance repeats it, and the label panel uses a daily value of 50 grams as its reference.
What almost nobody says is what that figure means. It is not an optimum: it is the amount that covers the needs of almost the whole healthy population. It is a floor, set so that nobody falls short — not a ceiling and not a goal. Mistaking the floor for the target is the error every other one grows out of.
The other range: for people who train
When strength training is involved, sports nutrition reviews work with a considerably higher range, between 1.2 and 2.0 grams per kilo, with the top of it reserved for calorie deficits, where protein protects lean mass while the weight comes down.
It is worth saying where each thing comes from: the 0.8 g/kg is a public recommendation from federal agencies; the 1.2 to 2.0 range comes from the sports nutrition literature and from professional society position stands. They are two different sources and they are not cited as if they were one.
The 10 to 35 % band
There is a third way of looking at it, by percentage of calories. The acceptable range for protein in an adult diet runs from 10 to 35 % of total calories. It is deliberately wide: inside that band there are many correct diets, very different from one another.
It works as a cross-check. If you do the grams per kilo and the result falls outside 35 % of your calories, something in the split does not add up.
«You can only absorb 30 grams at a time»
This gets repeated a lot and it is false as stated. The gut absorbs practically all the protein that reaches it; what saturates is not absorption but the muscle protein synthesis response to a single meal, which tops out somewhere between twenty and forty grams depending on the person and how much muscle they carry.
The practical consequence is not «never eat more than thirty» but spread it out: three or four servings of protein across the day do more than one enormous dinner.
What happens if you go over
In a person with healthy kidneys there is no public evidence of kidney damage from eating more protein than recommended. What does happen is more prosaic: protein is very filling, and every gram that comes in there is a gram that does not come in somewhere else. Eating 3 g/kg is not dangerous, it is simply unnecessary, and it crowds out the carbohydrate that feeds the training.
Anyone with diagnosed kidney disease is in a different situation, and that figure is set by their doctor, not by an article.
How to work it out in thirty seconds
- Weight in kilos × 0.8 → the minimum for not falling short.
- Weight in kilos × 1.6 → a reasonable starting point if you train for strength.
- Divide the result by the number of meals you eat a day.
At seventy kilos: 56 g as the floor, 112 g as the target while training, about 28 g in each of four meals.
Where each figure comes from
- The 0.8 g/kg figure and the 10 to 35 % of calories range are recommendations published by United States Government agencies.
- The 50 g daily value is the one set by the labelling regulation for the nutrition panel.
- The 1.2 to 2.0 g/kg range comes from the sports nutrition literature, not from a federal recommendation, and the text says so.
United States Government agencies publish in the open and their works are not subject to copyright under 17 U.S.C. § 105. Every figure can be checked one by one; the writing of this article is our own work.
This is a summary. The split across meals, the tables of protein content by food and how protein fits into the rest of the day are worked through in full. It is in the Codex of the Table, a 78-page PDF in Spanish, English and French.
Published by VILLUMINATIONS. This text is informational and does not replace the care of a licensed health professional.