Are Asians shorter than Caucasians due to genetics or low-calorie, low-protein diet?
Asians are shorter than Caucasians due to a combination of factors. Dietary differences and American culture have influenced Asian-American growth rates so they tend to be taller than their non-American kin, but not necessarily (my adult Japanese-American nieces are both less than 5 feet tall). Genetics plays an important role. Short parents have short children. Short populations tend to stay short. China has a very diverse population and has elements of the population that are genetically tall. Growth hormone production ultimately controls height. If the gland that produces it is not functioning properly the result is someone who is very short or very, very tall. This can be genetic recessive trait, it can be a genetic mutation, or it can be the result of disease or injury. Diet is also a factor. There growth can be inhibited by poor nutrition, simply not getting enough calories for growth, by not getting enough of specific substances such as calcium (most Asians are lactose intoleran
