Writing in the May issue of the American Journal of Preventive Medicine, researchers from the Centers for Disease Control and Prevention (CDC) examined the reasons behind a 41 percent increase in diabetes in American adults from 1997 to 2003.
In the new study, the researchers examined whether the rise in reported incidence of diabetes in recent years is due to a true rise in incidence or to better testing and a change in diagnostic criteria.
They reviewed data from the 1997-2003 National Health Interview Survey (NHIS) of the National Center for Health Statistics, CDC, which collected information from 31,000 American adults per year.
"Among US adults aged 18-79 years, the incidence of diagnosed diabetes increased 41% from 1997 to 2003. During this period of rapid change, incidence increased at a greater rate among obese people, resulting in obesity being more prevalent among incident cases at the end of the time period than at the beginning," said the researchers.
"Altogether, these data suggest that obesity is a large factor - although not the sole factor - in the increasing incidence of diagnosed diabetes," they added.
According to the study, around 7 people per 1000 were reported as suffering from diabetes in 2003, compared to around 5 per 1000 in 1997.
"Lifestyle interventions that reduce or prevent the prevalence of obesity among persons at risk for diabetes are needed to halt the increasing incidence of this disease," said the researchers.
The new findings only confirm what has long been known and what has brought the food industry under attack for contributing to the nation's health crisis.
Indeed, many in the food industry are concerned that their sector could be swamped by health-related lawsuits if certain types of food and obesity are conclusively linked. The precedent for suing food manufacturers over health claims was set in 2002, when two New York teenage girls sued McDonald's, blaming the fast food chain for the girls' obesity, diabetes and hypertension.
And in general the economic estimates of the impact of obesity are astronomical. Approximately $52bn in healthcare was said to be attributed to obesity in 1995, and by 2003, this figure had increased to $75bn.
In 2004 the CDC published figures claiming that 400,000 Americans die annually from obesity-related illness. This attracted a hail of criticism from consumer and industry groups that claimed the figures helped create a climate of fear by exaggerating the nation's obesity crisis.
The CDC printed a correction in the Journal of the American Medical Association (JAMA) at the end of January last year, and has since rounded the figure down to 365,000. However, the CDC's position remains that obesity is a major risk factor for the leading killers in the US: heart disease, type 2 diabetes and certain cancers. The CDC estimates that 65 per cent of American adults are either overweight or obese.