Seventy percent of American adults — and three of every four men 25 and older — were overweight or obese from 2007 to 2012, representing even more weight problems than estimated.

A study by the Washington University School of Medicine, St. Louis, published online Monday in JAMA Internal Medicine, found that 75 percent of men and 67 percent of women during that five-year span were overweight or obese, with the highest percentages among Mexican men at 80.9 percent and non-Hispanic African-American women at 82.6 percent.

It’s unlikely that obesity rates have fallen since 2012.

Graham A. Colditz and Lin Yang at the school of medicine used the latest available data from the National Health Nutrition Examination Survey to determine the prevalence of excess weight and obesity in the United States.

The data included information on height and weight, which are used to calculate a person’s body mass index. A BMI between 18.5 and 24.9 is considered normal. Someone with a BMI in the 25 to 29.9 range is considered overweight, and a BMI over 30 qualifies a person as obese.

The study involved 15,208 men and women, with 40 percent of the men being overweight and 35 percent obese for the 75 percent total, and nearly 30 percent of women were overweight and nearly 37 percent more were obese, for a total of nearly 67 percent.

The sample size was large enough to represent national rates of weight gain and obesity, with the 2010 U.S. Census showing 201 million U.S. adults 25 or older.

A study 20 years ago for the same age group showed 63 percent were overweight or obese, reflecting a sizable percentage increase.

Weight gain raises the risk of heart disease, diabetes, and certain cancers, including breast cancer, among other health problems.

“Clearly this is not a decline in the rate of weight gain and obesity,” said Ms. Yang, study author and a post-doctoral fellow at the medical school. “All the guidelines show we can improve weight maintenance through physical activity and healthy eating, but these strategies are not widely practiced. We need to accelerate obesity prevention and treatment.”

African-Americans had the highest obesity rates among both men, at 39 percent, and women, at 57 percent. The researchers found that 17 percent of black women and 7 percent of black men were extremely obese, meaning their body mass index topped 40.

Among the group labeled Mexican-Americans, 38 percent of men and 43 percent of women were obese. For whites, 35 percent of men and 34 percent of women were obese. No data were reported for Asian-Americans. 

Rates of overweight and obesity were comparable for younger — ages 25 to 54 — and older — ages 55 and up — adults, the study showed.

Among the recommendations are more bicycle lanes, parks, and exercise facilities; better availability and consumption of fruits and vegetables; a stronger physician focus on obesity, and less time in front of TV or computers.

Let’s Move Pittsburgh, a program at the Phipps Conservatory and Botanical Gardens, has just announced its “5-2-1-0 Movement” for children. It pushes for five daily servings of fruits and vegetables, two hours or less of screen time, one hour or more of daily physical activity, and zero sugary drinks and more water consumption.

“You have to shift to being more active with healthier food choices,”  said Dr. Karen Hacker, Allegheny County Health Department chief. “But that can be challenging when you see french fries on salads.”

The Block News Alliance consists of The Blade and the Pittsburgh Post-Gazette. David Templeton is a reporter for the Post-Gazette. David Templeton: dtempleton@post-gazette.com or 412-263-1578.

First Published June 23, 2015, 4:00 a.m.