American society has become “obesogenic” according to the US Centers for Disease Control and Prevention (CDC): their latest report shows that nine states now report more than 30 per cent of adults are obese, yet it was only ten years ago that no state had a 30 per cent or more rate of obesity in its adult population.

The nine states that surpass the 30 per cent obesity rate were found to be: Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, Tennessee, and West Virginia.

On its Obesity webpage, the CDC describes American society as “obesogenic”, where people live in environments that promote over-eating, unhealthy food, and physical inactivity.

The latest evidence appears to reinforce this: in just one year, since 2009, the number of states with an obesity prevalence of 30 per cent or more has tripled to nine, according to the CDC’s second MMWR “Vital Signs” report, released on Tuesday.

Moreover, not one state has met the Healthy People 2010 national goal of 15 per cent adult obesity prevalence, and only two, the state of Colorado and the District of Columbia report an obesity prevalence under 20 per cent (18. and 19.7 per cent respectively).

CDC Director Dr Thomas Frieden told the press that obesity is still a major public health concern in the US, and if we don’t continue to address this with intensive and comprehensive efforts, we will see more and more people getting sick and dying from obesity-related causes “such as heart disease, stroke, type 2 diabetes and certain types of cancer, some of the leading causes of death”.

The CDC report shows that based on self-report data, an additional 2.4 million adult Americans (aged 18 and over) entered the obese category between 2007 and 2009, representing a rise of 1.1 per cent.

Obesity-related medical costs are also high, says the report, estimating the total cost in 2008 at 147 billion US dollars, with obese people costing an extra 1,429 dollars each to treat compared to people of normal weight.

The report bases its findings on new figures from the Behavioral Risk Factor Surveillance System (BRFSS). This system yields state-level public health data and gives states a way to monitor their progress toward the national Healthy People goals.

The system gets it data from telephone surveys: about 400,000 people are surveyed for the obesity data. They are asked to give their height and weight over the phone. From this the survey calculates their BMI (Body Mass Index, the weight in kilos divided by the square of the height in metres).

A BMI of 30 and over counts as obese: and this would include for instance a woman 5 foot 4 inches tall (1.63 m) weighing 174 pounds (79 kilos) or more, or a man 5 ft 10 ins tall (1.78 m) weighing 209 pounds or more (95 kilos).