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Comment by oifjsidjf | Hacker News Reader

Really? So eating just potatoes and oats would give you enough protein for optimal development?

Protein is the only macronutrient that was shown to increase child height. Fats and carbs do not seem to have an effect on child height.

It's a known phenomena that when eg Japanese parents move to US their children grow taller than their Japanese peers, even though both parents are Japanese.

Obviously it's hard to say if protein is the only cause in this, it could also be others. Some people "blame" growth hormones in milk, no idea if that has any merit to it.

But the point is: nutrition DOES affect child height to a certain degree, not just the genes of the parents.

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My grandmother as many other people in rural Belarus during WWII survived on eating only potatoes, cabbage and carrots during 3 years of German occupation. There were occasional fish and mushrooms, but that was very minor.

Children born during that time or just before the war were not shorter than their parents.

While excessive protein is well known to simulate muscle growth, there are no indications that it is good for long-term health. And one still builds muscles with just 60 gram of protein per day, it just takes longer. One gets 60 gram of protein when eating enough potatoes to get 2500 kcal.

> survived on eating only potatoes, cabbage and carrots

Surviving and thriving are very different things. Even obese people could be told to have survived, because they live long years; yet, they leave many on the table.

> And one still builds muscles with just 60 gram of protein per day

Only untrained individuals can do that. Most of the population with just 6 months of training will easily hit the wall with less than 10% of calories coming from protein.

From the experience of my grandmother and her relatives people were not hungry or particularly thin or deficient. Of cause this is still anecdotical, but then consider aboriginal people from Papua New Guinea. Their primary source of calories for the whole life was varieties of sweet potatoes that had even smaller ratio of protein/calories than ordinary potatoes. By various estimates their protein intake was like 40 gram per day or even less. Yet they were muscular and healthy with no signs of deficiencies capable of doing a lot of heavy manual labor in their fields.

Then there were experiments some from over 100 years ago that showed that athletes at the top level can still improve their performance eating 60-65 gram of protein on average per day for over a year.

Then consider junk vegans who eat mostly potato chips. They do have health issues, but those can be attributed to consumptions of too much empty calories from heavily processed seed oils, not any kind of protein deficiency.

> Yet they were muscular

We should be careful not to talk past each other. In your previous comment you talked about muscle growth and muscle building. I took it to mean strength building, the one people do in the gym. Hence my comment on untrained individuals and the amount of protein required to build muscle. Anyone who would like to improve their strength and hypertrophy should better be careful to eat enough proteins.

No activity in the nature demands as much strength as the weight training activities in the gym. A small amount of protein may suffice for natives of Papua New Guinea.

As a side note, muscularity might mean different things. A lean individual showing muscular definition might be considered muscular, yet it doesn't mean that they have big muscles or that they are strong. In a similar manner, someone who looks big might look big because they have favorable fat distribution in their body. They may not be strong.

> athletes at the top level can still improve their performance eating 60-65 gram of protein on average per day for over a year.

Yes they can. They are probably mid-distance runners, not strength lifters. Not all types of sports demand high protein intake.

There is a book from 1907 by Russell H. Chittenden that discussed protein intake and various experiments, see

https://www.gutenberg.org/files/68830/68830-h/68830-h.htm#Pa...

I am not aware of modern studies that contradicted the conclusions there. Basically even with 60 gram of protein per day one can still maintain and improve muscular volume and strength. It just takes a lot more time compared with consuming 120-200 grams per day that are recommended by modern sport diets.

Evidence that protein requirements have been significantly underestimated Rajavel Elango 1, Mohammad A Humayun, Ronald O Ball, Paul B Pencharz Affiliations expand PMID: 19841581 DOI: 10.1097/MCO.0b013e328332f9b7

https://pubmed.ncbi.nlm.nih.gov/19841581/

Fair point. Though the war ended and I assume their dietary habits changed. So the children did not have this diet throughout their entire childhood.

It's known that bodies of children can "compensate" in later periods for the lack in previous periods. This is most noticable in gymnasts who relatively more often experience a delay in puberty due to their extreme training regiment, but if they stop the body "catches up".

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