CHICAGO (AP) _ Dr. Joyce Harp says TV images of flabby football players got her wondering.
``I thought, gosh, those guys look huge and they don't look muscular _ they look obese,'' Harp said, explaining what prompted a new study that suggests more than half of National Football League players would be considered obese by some medical standards.
The NFL called the study bogus for only using players' body-mass index, or BMI, a height-to-weight ratio that doesn't consider body muscle versus fat. And the players' union said there's no proof that obesity is rampant in the league.
But former defensive tackle John Jurkovic said he's seen plenty of evidence that players have gotten ``big as houses'' because of league pressure to intimidate opponents and win.
``The NFL teams want it because it's working,'' said Jurkovic, who retired in 2000. The 6-foot-2 former athlete said he ballooned up to 328 pounds after being pressured by a coach to get bigger.
The theory is that bigger men, especially linemen and defensive players, are better blockers and harder to move.
But the study suggests that bigger players don't make a team more successful. There was no relationship between teams' average player BMI and their ranking in 2003-04, the season studied. Arizona had the highest average BMI but also the worst record in its division.
Harp, a University of North Carolina endocrinologist, and UNC student Lindsay Hecht used statistics on the NFL Web site to calculate BMIs for 2,168 NFL players, nearly all those playing in the 2003-04 season.
Almost all the players qualified as overweight, and 56 percent had BMIs of at least 30 _ what doctors consider obese. For example, a 6-foot-2 man weighing 235 has a BMI of just over 30. Nearly half of the obese players were in the severely obese range, with a BMI of at least 35, and a small percentage were morbidly obese with a BMI of at least 40.
Harp acknowledged that without measuring body composition, it's uncertain how many players were truly fat, but she said it's unlikely the high BMIs were ``due to a healthy increase in muscle mass alone.''
``The high number of large players was not unexpected, given the pressures of professional athletes to increase their mass. However, it may not be without health consequences,'' the researchers wrote, citing previous studies that documented obesity-related problems, including sleep apnea and high blood pressure in NFL players.
The study appears in Wednesday's Journal of the American Medical Association.
While the study methods were not very scientific, players' growing girth ``is a major concern,'' said Dr. Arthur Roberts, a former NFL quarterback and retired heart surgeon whose Living Heart Foundation works with the players' union to evaluate heart-related health risks faced by current and retired players.
The increasing emphasis on size may be a bad influence on ``all the young kids that play football around the country ... and are trying to be like their heroes,'' Roberts said.
Players' union spokesman Carl Francis said health and safety are ``discussed all the time,'' and that while some players likely are obese, it's not a major problem.
NFL spokesman Greg Aiello called the study substandard and said there's no proof obesity is worse in the NFL than in U.S. society in general, where about 30 percent of adults are obese, based on BMI data.
``This was not a serious medical study,'' he said.