Nations that consume more protein in the form of meat, dairy, eggs, and fish tend to be taller, while those that obtain more protein from cereals tend to be shorter. Therefore, populations with high cattle per capita and high consumption of dairy live longer and are taller. Historically, this can be seen in the cases of the United States, Argentina, New Zealand and Australia in the beginning of the 19th century. Moreover, when the production and consumption of milk and beef is taken to consideration, it can be seen why the Germanic people who lived outside of the “imperium Romanum” were taller than those who lived at the heart of the Empire.Changes in diet (nutrition) and a general rise in quality of health care and standard of living are the cited factors in the Asian populations. Malnutrition including chronic undernutrition and acute malnutrition is known to have caused stunted growth in various populations. This has been seen in North Korea, parts of Africa, certain historical Europe, and other populations. Developing countries such as Guatemala have rates of stunting in children under 5 living as high as 82.2% in Totonicapán, and 49.8% nationwide.Height measurements are by nature subject to statistical sampling errors even for a single individual. In a clinical situation, height measurements are seldom taken more often than once per office visit, which may mean sampling taking place a week to several months apart.
In regions of poverty or warfare, environmental factors like chronic malnutrition during childhood or adolescence may result in delayed growth and/or marked reductions in adult stature even without the presence of any of these medical conditions. A study of 20th-century British natality trends indicated that while tall men tended to reproduce more than short men, women of below-average height had more children than taller women. Determinants of growth and height
The study of height is known as auxology. Growth has long been recognized as a measure of the health of individuals, hence part of the reasoning for the use of growth charts. For individuals, as indicators of health problems, growth trends are tracked for significant deviations, and growth is also monitored for significant deficiency from genetic expectations. Genetics is a major factor in determining the height of individuals, though it is far less influential regarding differences among populations. Average height is relevant to the measurement of the health and wellness (standard of living and quality of life) of populations.Attributed as a significant reason for the trend of increasing height in parts of Europe are the egalitarian populations where proper medical care and adequate nutrition are relatively equally distributed. The uneven distribution of nutritional resources makes it more plausible for individuals with better access to resources to grow taller, while the other population group who does not have so much of a nutritious food availability height growth is not as promising. Average height in a nation is correlated with protein quality.