"According to an American Medical Association report, 14.5 % of Americans in 1980 were obese, a total of 32,700,000 (based on a population of 226,000,000). If, as the above article states, the numbers of obese Americans have "doubled" in the past twenty years, this would mean there are now about 66 million of them. But thirty million of those fatties were created by a change in definition, so by the standards of 1980 [we would calculate an] obesity percentage of 12.85 percent, an actual decrease in obesity percentage since 1980."
http://econlog.econlib.org/GQE/gqe142.html
"According to an American Medical Association report, 14.5 % of Americans in 1980 were obese, a total of 32,700,000 (based on a population of 226,000,000). If, as the above article states, the numbers of obese Americans have "doubled" in the past twenty years, this would mean there are now about 66 million of them. But thirty million of those fatties were created by a change in definition, so by the standards of 1980 [we would calculate an] obesity percentage of 12.85 percent, an actual decrease in obesity percentage since 1980."