LOS ANGELES - Obesity prevalence was 30 percent or higher in 12 states of the United States last year, compared to nine states in 2009, the Centers for Disease Control and Prevention (CDC) said on Tuesday.

In 2000, no states in the country had obesity rates that high, and now obesity is a problem in all 50 states, the agency said in a report based on telephone interviews with 400,000 people.

Obesity rates vary by region, led by the South at 29.4 percent, followed by the Midwest at 28.7 percent, the Northeast at 24.9 percent, and the West at 24.1 percent, the report said.

Mississippi had the nation's highest obesity prevalence at 34 percent, and Colorado the lowest at 21 percent, according to the report.

Alabama, Arkansas, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Oklahoma, South Carolina, Tennessee, Texas, and West Virginia all had obesity rates of 30 percent or higher in 2010, said the report.

No state met the federal Healthy People 2010 goal of a 15 percent obesity rate. In fact, no state had a rate lower than 20 percent, the CDC said.

Obesity rates have kept rising despite a steady drumbeat of warnings that obesity causes serious health problems and increases the risk of premature death, CDC officials said.

An adult is considered obese if he or she has a body mass index (BMI) of 30 or greater.