https://immattersacp.org/archives/2008/09/trends.htm

Steady increase in number of obese adults drove sharp rise in overweight population since 1980

The prevalance of overweight and obesity changed little between the early 1960s and 1976-1980.


The prevalence of overweight and obesity changed little between the early 1960s and 1976–1980. Findings from the 1988–1994 and 1999–2004 National Health and Nutrition Examination Surveys, however, showed substantial increases in overweight among adults (see Figure). The upward trend in overweight since 1980 reflects primarily an increase in the percentage of adults 20–74 years of age who are obese.