Steckel analyzed height data from thousands of skeletons excavated from burial sites in northern Europe and dating from the ninth to the 19th centuries. Average height declined slightly during the 12th through 16th centuries, and hit an all-time low during the 17th and 18th centuries.
"Height is an indicator of overall health and economic well-being, and learning that people were so well-off 1,000 to 1,200 years ago was surprising," he said.
Northern European men had lost an average 2.5 inches of height by the 1700s, a loss that was not fully recovered until the first half of the 20th century.
Steckel believes a variety of factors contributed to the drop and subsequent regain in average height during the last millennium. These factors include climate change; the growth of cities and the resulting spread of communicable diseases; changes in political structures; and changes in agricultural production.
"Average height is a good way to measure the availability and consumption of basic necessities such as food, clothing, shelter, medical care and exposure to disease," Steckel said. "Height is also sensitive to the degree of inequality between populations."
The study appears in a recent issue of the journal Social Science History.
Steckel analyzed skeletal data from 30 previous studies. The bones had been excavated from burial sites in northern European countries, including Iceland, Sweden, Norway, Great Britain and Denmark. In most cases, the length of the femur, or thighbone, was used to estimate skeletal height. The longest bone in the body, the femur comprises about a quarter of a person's height.