Same population, different diets, different heights. There is a strong correlation between height and diet, which has been observed in many modern and ancient archaeological societies. One of those are the mayans who demonstrated a 13cm difference (5.12”) between social classes, the working and the ruling, which the main differentiator between , was diet:
A group named the Mayans who lived in South America, had a diet containing animal proteins and fats, at its early stages, presented with an average male skeletal height of 165 cm (5.4”)
As the civilization divided into social classes, the ruling class had access to the consumption of animal products, while the lower class had to resort to a grains & legumes based diet.
The ruling class average male height, as measured by their skeletal remnants, had increased to a height of 170 cm, as a result of such dietary changes
Whereas those who’s conditions forced them into a diet devoid of animal products, centered around grains and legumes, had faced a drastic decline of 8 cm in height. Dropping from 165cm to 157cm.
Making the difference between those who consumed animal products versus those who didn’t that of 13 cm of height (5.12 inches)
13 cm is no small difference, it’s comparable to life and death.
The question arises:
How does that happen?
The protein in animal products differs from that found in legumes and plants
Even if the amount is identical, the amino acids profile isn’t.
The protein from animal products is complete, meaning it has all of the essential and nonessential amino acids.
On the other hand, the protein from plants and legumes is incomplete, meaning it lacks many amino acids, especially tryptophan, cystine, methionine and threonine.
The required proper amino acids formula for hormone synthesis, lactation, and growth* to occur are only found in animal proteins.
Directly correlating with an increase of height to those who adopt it, and a reduction of life quality to those who don’t.
Anther population demonstrating the height-diet correlation is the dutch, their consumption of animal products and their tall heights.
More animal products -> 
taller population
