AMES, Iowa -- A study by two researchers from Iowa State University's Department of Health and Human Performance found that among linemen on 251 Iowa high school football rosters during the 2005 season, seven percent had body mass indexes that would be classified as adult class II obesity (35 or higher) -- with another 2 percent as class III obesity (40 or higher).
Kelly Laurson, an ISU graduate student in health and human performance; and Joey Eisenmann, an assistant professor in the department, co-authored a paper on their research titled "Prevalence of Overweight Among High School Football Linemen," which is being published in the Jan. 24/31 issue of the Journal of the American Medical Association.
According to Laurson -- himself a former center and defensive end at Iowa's Centerville High School before graduating in 1999 -- the study is a follow-up to a 2005 University of North Carolina study that found that 56 percent of all National Football League players from 2003-04 rosters would be considered obese by some medical standards. The NFL study also used body mass index (BMI) -- a statistical measure commonly used to measure obesity by determining the optimum weight of a person scaled according to height. The BMI is calculated as weight in kilograms divided by height in meters squared.
"Obesity among professional football players has been documented, with recommendations that it be further investigated among amateur athletes," wrote the researchers in the paper. "Adolescent overweight is related to unfavorable cardiovascular disease risk factors and predicts overweight in young adults. We therefore examined the prevalence of overweight and obesity in high school football linemen, the players who tend to be heaviest."
A representative statewide sample
The study's sample of 3,683 linemen included at least two teams from each of Iowa's 47 districts -- including all six classifications by enrollment size (4A, 3A, 2A, 1A, A, and 8-player) -- making the sample representative of all players. In addition to the percentage of linemen determined to be obese, the study found that 45 percent were overweight, with another 28 percent at risk for being overweight. The researchers compared their results to the 2003-04 National Health and Nutritional Examination Survey data for boys aged 12 to 19 -- the group most closely matching the players' ages -- which found just 18.3 percent to be overweight.
"We don't know if they're (the linemen in their study) big because they desire to play football, or big because of their lifestyle habits," said Laurson, the lead author on the paper. "We obviously suspect these linemen are being pressured by coaches to gain weight or may want to gain weight because when you watch the NFL, you see these big linemen. So they may desire to be big. They may have been big before starting high school football, but may desire to be bigger as they go through the sport."
The biggest linemen are also at the biggest schools, according to the study, with linemen from Class 4A schools having an average BMI of 29.1, compared to an average BMI of 27.2 for all the five smaller classes. As expected, the players also became bigger with age, with seniors having an average BMI of 28.5, compared with 28.1 for juniors, 27.4 for sophomores, and 26.1 for freshmen.
While the researchers believe their study is statistically valid, they admit that BMI may have limitations in determining a person's optimum weight.
"The BMI is what it is, but this is a study that opens the door for a closer inspection of this issue," said Laurson. "The BMI is such a simple measure and it does give you an estimate of body fat. Obviously these players are big and we're assuming there's some excess fat in there. The number that jumps out is 9 percent with severe obesity. That means they are in the range of adult level obesity already, and these players are only between 14 and 17 years old. What happens to them when they stop playing football? Finding obesity at that level is very significant, especially when considering the age of the athletes."
Implications beyond Iowa
In spite of the limitations of the measurement, the researchers believe the study has implications beyond Iowa. In fact, it may be conservative when compared with other states.
"If you went to states where football may be even more intense, you might see numbers that would drop your jaw even further," said Laurson. "This is just an estimate because it is only a study on Iowa players."
Raising national awareness was a goal the researchers had for the study.
"We wanted to make as many people aware -- including doctors, athletes, their parents, and coaches -- that this problem is out there," said Laurson. "There are potential problems for these players in the future. And there could be repercussions for these athletes in playing the sport."
He hopes that news of this research will focus attention on healthier weight gain among young linemen, warning "bigger, if it's fat, is not necessarily better."
