US obesity 'higher than thought'

The obesity problem in the US may be much worse than previously thought, according to researchers.

They said using the Body Mass Index or BMI to determine obesity was underestimating the issue.Their study, published in the journal PLoS One, said up to 39% of people who were not currently classified as obese actually were.

The authors said "we may be much further behind than we thought" in tackling obesity.

BMI is a simple calculation which combines a person's height and weight to give a score which can be used to diagnose obesity. Somebody with a BMI of 30 or more is classed as obese.
The US Centers for Disease Control says at least one in three Americans is obese.
Other ways of diagnosing obesity include looking at how much of the body is made up of fat. A fat percentage of 25% or more for men or 30% or more for women is the threshold for obesity. (BBC)