The U.S. obesity prevalence increased from 13 percent to 32 percent between the 1960s and 2004,according to a new study released Tuesday by researchers at the Johns Hopkins Bloomberg School of Public Health. (File Photo)

    WASHINGTON, July 10 (Xinhua) -- The U.S. obesity prevalence increased from 13 percent to 32 percent between the 1960s and 2004,according to a new study released Tuesday by researchers at the Johns Hopkins Bloomberg School of Public Health.

    The prevalence of obesity and overweight has increased at an average rate of 0.3 - 0.8 percentage points across different sociodemographic groups over the past three decades, said the meta-analysis, published in the latest issue of the journal Epidemiologic Reviews.

    The key findings include: in 2003-2004, 66 percent of U.S. adults were overweight or obese. Women between 20 and 34 years old had the fastest increase rate of obesity and overweight. Eighty percent of black women aged 40 years or over are overweight; 50 percent are obese. Sixteen percent of children and adolescents are overweight and 34 percent are at risk of becoming overweight in 2003-2004.

    "The obesity rate in the United States has increased at an alarming rate over the past three decades. We set out to estimate the average annual increase in prevalence as well as the variation between population groups to predict the future situation regarding obesity and overweight among U.S. adults and children," said Youfa Wang, lead author of the study.

    "Obesity is a public health crisis. If the rate of obesity and overweight continues at this pace, by 2015, 75 percent of adults and nearly 24 percent of U.S. children and adolescents will be overweight or obese," added the researcher.

    If nothing is done, obesity will soon become the leading preventable cause of death in the United States, the authors warned in their papers.

    The study authors included 20 journal papers, reports and online data sets in their meta-analysis. In addition, data from four national surveys were included in order to examine the disparities in obesity. They defined adult overweight and obesity using body mass index cutoffs of 25 and 30, respectively.