Market researchers estimate that Americans spend more than $60 billion a year on gym memberships, exercise equipment, weight-loss programs, and other diet aids. The latest statistics from the U.S. Centers for Disease Control and Prevention suggest they’re wasting much of that money.

Despite an intensive effort by the CDC, doctors, health insurers, employers — and spouses — the proportion of American adults who are obese keeps going up. According to the latest two-year figures from the National Health and Nutrition Examination Survey, 37.7 percent of U.S. adults in 2013-14 had a body mass index of 30 or higher.

The prevalence of obesity was greater among women than men (38.3 percent versus 34.3 percent), and the most alarming rates were found among minorities. According to the study, 56.9 percent of black women were obese in the most recent two-year period, followed by Hispanic women (45.7 percent), and Hispanic men (39 percent).

Although the change in the two-year period from 2011-2012 was small — the earlier obesity rate was 34.9 percent — public health officials were disappointed that a decrease in sugared-soda consumption and other changes in dietary habits have not stopped or reversed the escalating rate of obesity.

The same statistical analysis gave a somewhat brighter picture for the nation’s children: Although 17 percent of young people ages 2 through 19 were obese, that is the same figure as 2003-04. If American children are doing a better job of keeping off excess weight, it is time for parents to take a lesson from their offspring.

First Published November 15, 2015, 5:00 a.m.