I think of Michelle Obama as the First Lady of Nutrition, the most environmentally aware person to yet occupy the White House. In March 2009 she planted an organic vegetable garden on the White House lawn to give her family homegrown food, to provide at least a topic of discussion at state dinners, and to create a place where children and teachers could learn about healthy food.

And they need to learn. It seems incongruous that the richest country suffers from such poor nutrition: most American children eat far fewer fruits, vegetables and whole grains than they need, and far more salt. They drink more soda than milk. More than a third of Americans – and half of all African-Americans – are obese. They are overweight and underfed – a combination that seems unfathomable to those of us who equate skeletal images with starvation. But it is real.

Michelle’s efforts brought a blistering response from the food lobby. Organic gardens were elitist, while corporate agriculture could feed the world. The lobby poured millions into fighting taxes on sugary sodas and persuading Congress to declare pizza a vegetable . . . just like catsup.

Nutritional issues are most severe in our inner cities, where the absence of decent markets makes the residents captive to both high prices and unhealthy food. One response is the emergence of community gardens on vacant urban lots. Detroit has over 1500 such gardens. They are small, often isolated. But what a difference they could make if they joined together to grow – and to demand – healthy food for the city's poor.