America's First Lady, Michelle Obama, has launched a campaign to improve the way families eat, encouraging Americans to face the fact that one in three children is overweight or obese.
As part of her initiative, she stressed the need to make healthy food more accessible. I met one couple who are trying to do just that, by running a mobile farmers' market in Virginia.
It is a sight that makes people stop and stare.
As Mark Lilly's big white bus heads along rundown city streets, the slogans painted on its side are as colourful as its owner: "Feeding the community one stop at a time. Support local farmers. Get local produce. Get on the bus, Gus!"
Virginia businessman Mark Lilly bought his 23-year-old bus on the internet. The day I joined him for the ride, he and his wife Suzi began at home, packing the aisles with organic produce they had sourced from local farms.
Baskets of colourful apples and squashes sat next to fistfuls of greens: kale, spinach, cabbage. And there was home-made apple pie.
The specialised farmers' market is becoming a colourful staple of American city life.
Mrs Obama presided over the opening of Washington's latest market in September, just a stone's throw from the White House.
What makes this venture different is Mr Lilly's determination to focus on "food deserts", those blighted urban neighbourhoods where fast food is the rule, and fresh produce very much the exception.
Much of the city of Richmond, Virginia, is historic and impressive. But as we drive into the district of Church Hills, the couple talk about the damage done by crack use.
We pass liquor stores and check-cashing outlets and row after row of boarded up windows.
We stop in the empty parking lot of an abandoned supermarket, over the road from a huddle of drunks, and wait for customers to come.
Mark Lilly is a man on a mission.
Cowboy hat jammed firmly on his head, he bursts with enthusiasm as he woos folks off the street: "This is spaghetti squash. You can make it go for a family of six. They're the freshest eggs, got them this morning. Here, take these packets of seeds, get the kids to start a garden."
In between sales, he sits in a big Amish rocking chair out on the sidewalk, looking for new custom.
It would be easier, he says, to set up at a farmers' market where customers tend to have money to spare.
He gets his steadiest income from his weekly delivery of fresh food boxes direct to customers' homes, known as a CSA scheme, or Community Supported Agriculture.
Displayed prominently in the bus window is a sign saying that he can take food stamps in payment. But still, he says, he is running a business, not a charity. And his produce costs more than fast food.
A lot of people say they do not have the time to cook. Or they just do not know how. "As Americans we don't have a culture of food really. It's fast food. We subcontract everything out," Mr Lilly says.
And he tells it like he sees it, saying that it is all about choice.
"Folks here are addicted to bad food and first you've got to wean them off it before you can sell them the good stuff," he says.
He enjoys parking in front of fast food stores, just to make a point. But then he says, he will often have people leave after browsing.
"Then I'll see them go buy lottery tickets or liquor. That's frustrating," he says.
Having a ball
On this day, those who get on the bus, seem genuinely appreciative.
Rita Monford was walking by, telling her 11-year old granddaughter there was nowhere to buy any decent fresh fruit.
Ten minutes on the bus, and her shopping bag was full: "I got cabbage, I got squash, I got tomatoes, I got apples. We're going to have a ball!"
For some, it is more than shopping - it is a family experience.
Mark and Suzi Lilly give out cooking advice and recipe leaflets along with the fruit and veg.
And Mr Lilly brings in regulars to his vintage bus with thoroughly modern marketing techniques. From his mobile phone, he posts to his Facebook and Twitter accounts about what is in stock and where he is parked.
It is only one venture, but so far it is succeeding. Mark and Suzi Lilly have already bought a second bus.
He would like a whole fleet. But his success depends on community support and on those who have less deciding that the food he sells is worth the extra expense.