According to the Centers for Disease Control and Prevention, rates of obesity have increased dramatically over the last 20 years. In 1990, no states had a rate of more than 14 percent obesity among their adult populations. In 2005, all 50 states had obesity rates of at least14 percent.

The problem is particularly bad in the South: In 12 out of 16 Southern states, at least 25 percent of the adult population is obese. Only five other states can match these numbers. North Carolina’s obesity rate is between 25 percent and 29 percent, about average for the increasingly rotund region.

So why is the obesity epidemic particularly bad in North Carolina and the South? According to Eric Finkelstein, the director of public health economics at RTI International, there are both obvious and unexpected causes. Here’s a hint: barbecue and hush puppies aren’t helping already strained waistbands.

Why are the obesity numbers so high in the South? Is it because there are a disproportionate number of low-income people in the region?

It’s actually got more to do with minorities. Minorities are more likely to be obese. So if we have a disproportionate number of minorities, it’s not surprising we have a disproportionate amount of obesity. If you look at a state like Colorado, which has low rates of obesity, they have very few minority people living there. As far as the link between income and obesity, there’s really not a correlation. In fact, if you look at men, there is no correlation at all between income and obesity.

Do the high rates owe something to the traditionally heavy Southern diet?

People who live in New York City do a lot more walking than people here. We’re much more dependent on cars than other locations. We also have a cultural bias toward fried food. In a sense, it’s more difficult to be thin here than it is in a place like Manhattan.

What are the consequences and costs to the state?

Obesity is certainly costly to the Medicare and the Medicaid programs. More obese people are on Medicaid than private insurance. Half the costs of obesity are paid by the two programs. An average person’s tax bill is $250 higher due to obesity. Employers take a hit as well, due to reduced productivity, absenteeism and workers’ compensation claims.

Should North Carolina legislators step in to do something?

Here’s an anecdote: If I say to you, “Listen, I want to take you out to lunch,” should I be mad if you get a big meal and then you want me to pay the bill? That’s what we’ve essentially done with Medicare and Medicaid. If we keep these programs as entitlement programs, we can’t feel bad that they cost a lot of money. The better strategy is to look at kids who don’t have the knowledge or opportunities that adults have.

What can be done to ameliorate the situation?

They should revisit past policies and see if they are doing more harm than good. Look at zoning laws and how they encourage use of cars and reform subsidies and healthcare financing subsidies to employers. They should really focus on kids and look at mandatory physical education and keeping the phys. ed. requirements in No Child Left Behind.

Finkelstein’s book, The Fattening of America: How the Economy Makes Us Fat, If It Matters and What To Do About It will be released in December.