Those of us who identify as being "vertically challenged” tend to reach for stilettos, or tweak our ensemble to appear taller than we really are. In the U.S., the average height is 5 feet 9 inches for men and 5 feet 4 inches for women — but how do we compare to the rest of the world?

A 100-year global study published in the journal eLife found Americans have, on average, become shorter compared to our counterparts across the world, such as the Dutch and Latvians. Dutch men are the tallest, with an average height of 6 feet, while Latvian women find themselves on the higher end of the height chart, with an average of 5 feet, 7 inches. The top tallest countries for men are the Netherlands, Belgium, Estonia, and Latvia. Meanwhile, the top four tallest countries for women are Latvia, the Netherlands, Estonia, and the Czech Republic.

The shortest men can be found in East Timor, with an average height of 5 feet 3 inches, while the shortest women are in Guatemala, with an average of 4 feet, 11 inches. This doesn't differ too much from 1914, when Guatemalan women were ranked as the world's smallest at 4 feet, 7 inches.

So, what's the difference between the tallest and shortest countries in the world?

Statistically speaking, there is a 9-inch difference for men, which is an increase of 2 inches on the height gap since 1914. For women, the difference has remained the same across the century at about 8 inches. On average, the height difference between men and women has remained largely unchanged over 100 years — the average height gap was about 4 inches in 1914 and is 5inches in 2014.

Researchers from the Imperial College London in collaboration with the World Health Organization used data from most countries in the world, tracking height among young adult men and women between 1914 and 2014. Information gathered included military conscription data, health and nutrition population surveys, and epidemiological studies. These were used to generate height information for 18 year olds in 1914 (who were born in 1896) to 18 year olds in 2014 (who were born in 1996).

Some countries have gotten shorter by as much as 2 inches in Sub-Saharan Africa over the last 40 years, including Sierra Leone, Uganda, and Rwanda. In East Asia, countries like South Korea and China have seen a boost in height with men and women now taller than their Japanese counterparts.

“The most striking finding is that despite the huge increases in height seen in some countries, there is still a considerable gap between the shortest and tallest countries,” said Mary De Silva, head of population, environment and health at the Wellcome Trust, who helped fund the study, in a statement.

More research is needed to understand why this gap exists and how to reduce it by addressing health issues that persist on a global level.

Variations in height are influenced by genetics and nutrition. Previous studies have found the difference in height between individuals is determined by genetics. Heritability of human height has been calculated by determining the degree of resemblance between relatives. For example, a 2010 study found heritability of height is 80 percent, based on 3,375 pairs of Australian twins and siblings.

This is why there is a discrepancy in height between different ethnic populations who have different genetic backgrounds, and reside in different environments. In Asian populations, height heritability is found to be 65 percent. Diversities in heritability are also linked to distinct environments, including climates, dietary habits, and lifestyle.

Nutrition places a crucial role in height, especially for children. Caloric intake from birth to about two years of age helps maximize the genetic potential for height. In a study published in The Journal of Nutrition, malnutrition in children younger than two years old can cause stunted growth in comparison with their parents and well-fed siblings. However, these children were able to “catch up” with proper nutrition. With increased caloric and vitamin intake, 30 percent were no longer stunted by the age of 8.5 years, and 32.5 percent were no longer stunted at 12 years old.

In the U.S., Americans are getting shorter over time compared to the rest of the world due to our growing waistlines. The Western diet is high-fat, high sugar, which is associated with obesity, and may lead to a shorter stature. Some pediatricians believe obesity leads to the early onset of puberty. In women, estrogen can lead to the closure of growth plates at the ends of long bones, which are responsible for linear growth. So, if this occurs earlier, this increases the likelihood of being shorter later in life.

In other words, perhaps taking a break from the burgers and fries can help Americans reach the top 10 list of tallest people in the world, like back in 1914.

Source: NCD Risk Factor Collaboration. A Century of Trends in Adult Human Height. eLife. 2016.