In a nutshell, according to the Center for Disease Control: 35.7% of U.S. adults were obese in their most recent survey: 2009–2010. The U.S. National Health and Nutrition Examination Survey See report: http://www.cdc.gov/nchs/data/databriefs/db82.pdf

The report notes: “There was no significant difference in prevalence between men and women at any age. Overall, adults aged 60 and over were more likely to be obese than younger adults. Among men there was no significant difference in obesity prevalence by age. Among women, however, 42.3% of those aged 60 and over were obese compared with 31.9% of women aged 20–39.”

Find chart at: http://www.cdc.gov/obesity/data/adult.html

In a different report using the same survey data:

• 31.2 percent of adults (over age 20) had BMIs under 24.9 and so were considered normal weight or underweight.
• Another 33.1 percent had BMIs from 25 to 29.9, and so they were considered overweight.
• The group with BMIs of 30 or higher—people considered to have obesity—amounted to 35.7 percent.                       Within that 35.7 percent were 6.3 percent who were defined as morbidly obese, with BMIs of 40 or higher.
• http://www.win.niddk.nih.gov/statistics/index.htm#graph