• Obesity rate in southern state dire at more than 34% • One in five Mississippi residents are without health insurance • Warning that healthcare costs could cripple state's economy

A third of the population of Mississippi will have diabetes by 2030 and need costly care to stay alive, which will have a devastating impact both on them and the state's economy, according to a leading physician.

Dr Richard deShazo at the University of Mississippi medical centre in Jackson, is one of a group of physicians and academics who are trying to warn families about the dangers and consequences of obesity and teach them how to prevent their children gaining weight and damaging their health. Mississippi has long been the state with the highest obesity rate in the United States, dropping only slightly in the latest government survey to second place to Louisiana where 34.7% of the population is now obese, compared with 34.6% in Mississippi. Thirteen states, mostly in the south, have obesity rates of more than 30%.

The situation in Mississippi is dire, said deShazo. “We're going to have about a third of our population with diabetes by 2030. If you look at the economics of that, the downstream disability, it's very difficult to calculate the long-term effects but it's very hard to tell how the state can support itself,” said deShazo. The 2012 “F as in Fat” report by the Trust for America's Health and the Robert Wood Johnson Foundation found Mississippi had the highest rate of type 2 diabetes in the US, at 12.3%, based on 2010 figures. At the current rate of increase, said deShazo, that would be a third of the population by 2030. The 10 states with the highest diabetes rates are all in the south.

Diabetes is one of the most problematic consequences of obesity, along with high blood pressure, stroke, cancer and damage to the joints of the leg. All of this results in disability. People with advanced diabetes have kidney failure and will end up on regular dialysis to stay alive and are at risk of blindness and foot amputations.

The health problems are hitting people who would normally be earning money. “We're seeing 30- and 40-year-old people getting type 2 diabetes that we used to see in 50- and 60-year-old people,” said deShazo. “So now that disability curve is shifting further and further to the left, to a younger and younger under- or unemployable population.

“The state department of health is under-funded and the university is really about the only component right now that has enough physicians and health professionals in it to take a leadership role, so what we've tried to do is do as much as we can with what we have.”

Major efforts by the University of Mississippi medical centre team may be paying off with a drop in the child obesity rates, which has been encouraging, but is only in the white, more affluent population and does not include African Americans or poor whites, said deShazo. Health literacy – the basic understanding of what causes you to get ill – is extremely low in the state.

Mississippi does not have the healthcare services in place to cope and 19% of the population, around 275,000, are uninsured – almost one in five. The state has turned down federal money for Medicaid expansion, which would have made somewhere between 200,000 and 400,000 more people eligible. It has the lowest rate of physicians to patients in the United States. Many people at risk of diabetes and other health problems do not have access to primary care, where they can be advised on the prevention of illness and monitored. The figures are worst for the people of the Mississippi Delta, who have very low incomes, if any, and low levels of education.

The University of Mississippi medical centre has a federal “navigator” grant, to help people through the complexities of signing up for health insurance coverage on the government website. The only other organisation in the state with a grant is the Oak Hill Missionary Baptist Church in Hernando. Its pastor, the Rev Michael Minor, has been working to reduce obesity since 1996, when he arrived, by changing the type of food available at church gatherings and hanging a “No Fry Zone” notice in the kitchen.

First lady Michelle Obama, no doubt keen to support any efforts in obesity-ridden Mississippi, invited him to the White House as part of her “Let's Move” campaign. Taking on enrolment to health insurance under the ACA seemed like a natural progression to Minor.

“Our whole ministry is health of mind, body and spirit. If you can't see the doctor on a regular basis, you are going to be sick a couple of ways,” he said.

“I think it's everybody's right. We talk about having the best healthcare [in the world] in America. We have got the best healthcare in America for some people in America. For everybody else, we have got the worst healthcare, because they have got no access to it. I didn't see it until I knew some members who were working. Either the job did not give some benefits or they couldn't afford what there was. They are the working poor.

“I had a member who just needed to get a prescription and the prescription was $300 for [drugs to prevent] blood clots. She didn't have $300.”

Minor, a Harvard graduate in economics, applied for a grant and was awarded $320,000 to cover 40 counties. They now have 82 navigators in total, the vast majority part-time. “I realised the best thing for this job was people in the community who are probably only available in the evenings and weekends,” he said.