Kai Ryssdal: You want to think about food in this country nowadays, calories are pretty much how we do it. There are laws saying restaurants have to post calorie totals for everything -- they're the first thing we look for when we flip over that pint of ice cream or cookies we're thinking about. A better metric, though, might be cholesterol or blood pressure or joint pain or shortness of breath. All of which -- and more -- are tied to our collectively growing waistlines. A new documentary tonight on HBO chronicles and criticizes obesity in America. It's called "The Weight of the Nation." John Hoffman is the executive producer. John, welcome to the program.

John Hoffman: Thank you. I'm glad to be here.

Ryssdal: Are you trying to turn obesity into a campaign, I guess? Much like breast cancer has turned into.

Hoffman: I would say we're trying to sound a very, very loud alarm. I don't know that we're setting out to establish a campaign where we're going to be revisiting this every year. This is an issue that the nation has to address, has to make a priority. You have 1 out of 3 children born today who will develop diabetes in their lifetime. And in the instance of obesity, it's driving our health care costs possibly to the point of bankruptcy. I could go on and on citing reasons why this really has serious consequences for the future competitiveness and health of the country.

Ryssdal: Here's another one: Did I read someplace that obesity-related expenses contribute to something like $200 billion a year in health care costs?

Hoffman: That's right. And by 2018, it's expected to be $300 billion. And half of that will be borne by Medicare and Medicaid.

Ryssdal: So here comes the part of the interview where I say what a lot of people think, but are afraid to say it. There's a school of thought out there that goes: You know what, if these people who are overweight would just get off the couch and get some exercise and eat a little less, we'd take care of this.

Hoffman: There's no question that for people to lose weight, they do need to exercise more, they need to eat less. One way to think about obesity is that it's an unintended consequence of progress -- comparable to global warming.

Ryssdal: That's a great line actually -- unintended.

Hoffman: It's only in the past really 50, maybe 100 years, where you have a population that has food at arm's reach at all times. The policies that were put in place that shaped our agricultural system, that enabled to feed this growing nation -- none of these policies envisioned a world that would result in us eating more and moving less. But we've solved some major public health problems. We did it with smoking sensation and no one really believed that that was possible 30 years ago. They could not envision a world where we could use policy, we could use the marketplace -- to taxation -- to really shape purchasing behaviors. Some would argue that we have to employ the same tactics to really reshape our food environment.

Ryssdal: That was a long and brutal struggle, though, the whole war against tobacco and it's ongoing and there is success. But the food industry and the soft drink industry and the consumer rights industry will mount ferocious opposition to efforts to legislate this problem away.

Hoffman: If we were all to cut our consumption of food by 100 calories a day, that would cost the food industry between $30-40 billion a year. Now, how do you ask an industry to voluntarily not grow, but shrink by $30-40 billion a year? It's not going to happen. But we have to have industry at the table as a participant in rethinking the American diet because they have engineered a diet which is not only not health promoting, but it is damaging to our nation's health and to the health of children and we just -- we are better than that.

Ryssdal: John Hoffman is the vice president of documentary films at HBO. He's also the executive producer of "The Weight of the Nation," which is on HBO tonight. John, thanks a lot.

Hoffman: Thank you.