Expressing concern about the high childhood obesity rates in the African-American and Latino communities, the first lady said those trends lead to diabetes and other chronic illnesses "that we will be paying for as a nation."
Obama said she was "hesitant to use the word crisis" when it comes to childhood obesity, but said that "we have to turn the page" and embrace healthier lifestyles.
"I don't think we have to call it a crisis to make change. It is what it is," she said. "You can look in your own neighborhoods, in your own families, in your own lives and see the truth of that. So we don't need someone to label it to know that we can fix it."
"Government can't do it all," she said, emphasizing the big impact of "little, incremental changes" like walking more and limiting soda.
"Those things will eliminate obesity and cut down on costs. I mean, we're spending about $120 billion additional a year on our health care system as a result of these sort of chronic illnesses that you see that are connected to obesity. We already know that."
Obama said her focus was on "talking with young people before these habits are ingrained about what it means to grow your own food, what it means to eat something that's grown locally, because what I found was that kids are very simple. They eat what tastes good and if a carrot tastes good, they'll eat it. And what we've found is that freshly grown food is -- it just tastes better. "
Students from the Bancroft School in Washington, D.C., participating in a program with the White House Kitchen Garden have "learned so much about where food is grown," Obama said. "They take this information back. They educate their parents. They start asking for changes in their own diets."
The first lady said that while knowledge is crucial, it doesn't solve the problem that fresh fruits and vegetables aren't readily accessible or affordable in many communities. The administration would be focusing on improving the nutritional value of government-provided meals for children, she said.
"Through the lunch programs, more and more kids, particularly in this economy, are getting breakfast and lunch at school. And we need to do a better job of making sure that those meals are as healthy as they can be. "
Outside of schools, she said, people are replicating the 1,100-square-foot garden on the South Lawn, which she said cost less than $200 to plant.
"There are thousands and thousands of community gardens that are being planted in urban environments and in rural communities all over this country," she said. "What we've tried to demonstrate is that it's not easy, but it's not impossible, and it's not economically out of reach… Now I have gardeners and people who help take care of it, but there are also people who are coming together around their neighborhoods to do what we're doing here at the White House."
And even the first family indulges in guilty culinary pleasures from time to time. The first lady said she can relate to her husband's penchant for Five Guys Burgers and Fries.
"I love french fries: my favorite food," she said. "That's part of what we try to teach our kids. It's not about never, ever. There are some people who make that choice. We're not one of those. I love food. It's really about balance and choices."
"My hope is that if I play a role in sort of ringing the bell of prevention and wellness and exercise, if that changes somebody's life or it sets a new tone for the next generation, I think that can be helpful."