Key factors affecting height

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Key factors affecting height

I read a very useful paper yesterday and I will present the keys facts and some of the graphs of the data used for these conclusions.  There is an interesting explanation for the differences in average height between different countries based on quality of protein consumed and not just quantity.  This might explain why countries like Japan have stopped growing well below the average height in many western nations despite having a very high standard of living.  It might also better explain the height differences between Africans and Asians.  Takeaway point - children should be fed with more animal and dairy proteins to give them more height.

Paper: https://www.sciencedirect.com/science/article/pii/S1570677X16300065

Key Conclusions:

• This study shows that nutrition in the examined regions consists of three fundamental types of diet based on rice, wheat and milk, respectively.
• Male height in developing countries correlates with protein quantity.
• Male height in developed countries correlates with protein quality.
• Low protein quality can explain the unexpectedly short height means in the highly developed countries of East Asia and wealthy Asian oil superpowers.
• Children's mortality and total fertility are the most important socioeconomic factors correlating with stature.  The correlation of average height and mortality rate points to the importance of a disease-free environment.  Whereas the correlation of average height and total fertility (the number of children who would be born per woman (or per 1,000 women) if she/they were to pass through the childbearing years) shows how having a larger number of children will mean less resources per child leading to lower height.

The most fundamental finding is that the nutritional correlates of male height in North Africa, Asia and Oceania are very different and primarily depend on protein quantity, not protein quality.  Furthermore, three basic nutritional styles can be distinguished, depending on the major source of protein:

• The first nutritional style (in tropical Asia) is based on rice and is also characterized by a very low consumption of protein and energy. It is accompanied by very small statures between 162 and 168 cm.
• The second one (in the Muslim countries of North Africa and the Near East) is based on wheat and the consumption of plant protein reaches the highest values in the world. The intake of total protein and total energy is relatively high as well and comparable with Europe, but the average height of young males is still rather short and does not exceed 174 cm.
• The third one is based on animal proteins (particularly those from dairy) and is typical of Northern/Central Europe. This region is characterized by the tallest statures in the world (>180 cm), being matched only by the inhabitants of the Western Balkans, in which we can presume extraordinary genetic predispositions.

Graphs:

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Quote from: myloginacc on November 26, 2018, 05:15:46 PMSorry, your thread looks like it has great information, but I want to make some quick points, before I take the time to read it more in depth.

Southwestern Europe is still shorter than Northern Europe, despite similar living standards and diets.

The paper explains that "In taller nations, the intake of protein and energy no longer fundamentally rises, but the consumption of plant proteins markedly decreases at the expense of animal proteins, especially those from dairy. Their highest consumption rates can be found in Northern and Central Europe, with the global peak of male height in the Netherlands (184 cm)."

Quote from: myloginacc on November 26, 2018, 05:15:46 PMLikewise, diets can be pretty similar across most of Latin America, but their average heights aren't. There's also heavy meat and dairy consumption in some of those countries, but average height doesn't compare to Northern Europe.

Alas Latin America is omitted from the study so I cannot comment.  Might be interesting to get stats and see if there is a similar pattern.  I have feeling that diet in south America is quite varied with a distribution in rice, wheat, plant based and animal protein.  As the study notes there is an order of importance - first quantity of protein (overwhelmingly important in developing nations), then quality of protein (important in developed nations where scarcity is no longer a problem).  The poverty levels in some south American countries and lack of sanitation is significant.

Quote from: myloginacc on November 26, 2018, 05:15:46 PMFurthermore, if diet was the main component of height, Northern Europe would have kept a similar pace of growth. However, like Japan, height increase has also basically slowed down to a halt there.

As mentioned there is variation in the quality of protein and the correlation between different types of protein and height.  Please read the paper carefully - I presented a summary as I expected that otherwise my post would not be be read at all.  I suspect there is any case a limit to the benefit in terms of height for reproductive success and overall health thus applying negative selection pressure after a certain height.

Quote from: myloginacc on November 26, 2018, 05:15:46 PMJust take a look at Finland, one of the most developed nations in Europe, with very heavy dairy

I note from the paper:
"These results confirm that red meat and eggs are the most height-related components of the human diet after milk, which primarily stems from the complete amino acid spectrum of their proteins"
Perhaps their diet is not as rich in red-meat for example?

Quote from: myloginacc on November 26, 2018, 05:15:46 PMI don't think you are arguing that genetics isn't one of the main factors. You even include an allusion to that in your OP.

The paper does provide some details about genetic correlations which of course exist.  But I do think that given the same environmental factors, including diet, sanitation, health care etc I would expect the average heights to reach close to the same values even across nations.  I would then expect any variations in the normal distribution to be explained by genetics.

Quote from: myloginacc on November 26, 2018, 05:15:46 PMI just don't want more Bruces thinking they stunted 10cm off their height, despite being from middle-class families.

As mentioned in my previous posts - there are a lot of factors and I would expect the Bruces of the world to understand that with all things being equal in terms of nutrition, sanitation, health care etc then genetics will become a more likely explanation for any stunted height.

Quote from: myloginacc on November 26, 2018, 05:15:46 PMAgain, taking the example of Japan and Europe, some of their periods of fastest height increase included two world wars. Their economies are stronger than during wartime, and healthcare, plus access to it, is also much better than in those times. How can you conciliate that with the fact both groups have had their average height increase significantly slowed down over the last decades?

That's quite interesting.  I was watching a cookery program yesterday which was on this occasion about Japanese cuisine - and it was noted that during world war 2, Japan had a shortage of rice.  A popular dish at this time was Okonomiyaki  - a pancake made with wheat, eggs and vegetables.  This meal would have a provided better quality of protein than the traditional rice based meal.  This is pure speculation but illustrates how the effect of shortages during war time may temporarily change the diet for better!

Quote from: myloginacc on November 26, 2018, 05:15:46 PMMalnutrition causes significant height stunting. Not as good nutrition does not cause significant height stunting.

Yep totally agree - which is why in developing countries where malnutrition is likely, the quantity of protein is more important than quality.

Quote from: myloginacc on November 26, 2018, 05:15:46 PMTaking the example of the Dinka people, assumed to be the tallest in the world:

So, war, famine, disease, and having to live life as refugees only stunted their average height by 4.9cm, and most Africans and Asians already seem to have lower height heritability than Europeans.

This is interesting.  I will need to think about this further.  I suspect that the effects of inherited height only become apparent when the quantity and quality of nutrition, healthcare, sanitation etc surpass a threshold. 

Quote from: myloginacc on November 26, 2018, 05:15:46 PMThe fantasies some people here have that they'd have been 6 feet tall instead of 5'6 if not for X are completely bogus. If you didn't undergo some form of famine, you didn't stunt your height in any significant way (>1.5cm). I just wanted to make that clear.

Agreed.

Quote from: myloginacc on November 26, 2018, 05:15:46 PMPopulations around the world aren't all supposed to reach the same average height as long as they all keep the same nutrition and lifestyle over a century. That's a fairy tale.

I am not convinced it is.  I think there is more research needed.