Feb. 26, 2013 -- As she celebrates the third anniversary of her Let's Move! initiative, first lady Michelle Obama told "Good Morning America" co-anchor Robin Roberts that the country is seeing real "movement" on the issue of childhood obesity.

"We've really changed the conversation in this country. When we started, there were a lot of people in this country who would have never thought that childhood obesity was a health crisis. But now we're starting to see some movement on this issue," the first lady told Roberts. "Our kids are eating better at school. They're moving more. And we're starting…to see a change in the trends. We're starting to see rates of obesity coming down like never before."

"What we're seeing is that there's hope, and when a nation comes together, and everyone is thinking about this issue and trying to figure out what role they can play, then we can see changes," she said.

Mrs. Obama is set to embark on a star studded national tour this week to promote and celebrate her Let's Move! initiative. Her first stop will be in Clinton, Miss. on Wednesday when she appears at an event highlighting healthy school lunches with Rachael Ray.

"I'm going back to Mississippi because when I first went there, Mississippi was considered one of the most unhealthy states in the nation," Mrs. Obama said.

"If we could fry water in Mississippi, we would, we would do that," Roberts, who grew up in Pass Christian, Mississippi, said. "Food is a culture."

"But the good news in Mississippi is that they've seen a decline in childhood obesity of 13 percent, so we're gonna go celebrate and highlight what has been going on there. There's still work to do," the first lady said.

On Thursday, the first lady will travel to her hometown of Chicago, where she will be joined by Olympic gymnasts and tennis star Serena Williams to promote more physical activity in schools. Later in the day, Mrs. Obama will discuss healthy food choices at a Wal-Mart store in Springfield, Mo.

Mrs. Obama said she will announce a new initiative called the "My Plate Recipe Partnership," which will provide families with online access to healthy recipes that meet the My Plate guidelines, the U.S. Department of Agriculture's replacement of the food pyramid.

"More and more chefs, more and more food companies are understanding that they have to find ways to help families do this in a way that's gonna taste good, that kids are gonna like it," she said.

The first lady, Roberts and Chef Marcus Robert Samuelsson, who owns Red Rooster Harlem in New York City, cooked a healthy meal of beef stir fry and broccolini together on the "Good Morning America" set. Mrs. Obama admitted "it's been a while" since she's cooked for her family, but said she looks forward to the day she can whip up meals for her husband and daughters.

"I walk in the kitchen every day, every day," she joked.

But cooking for her family isn't the only thing Mrs. Obama said she misses since becoming first lady.

"Going to Target for me is like a dream, you know? That one time I went, you noticed it created a stir. I'm gonna do it again, doggone it. Next four years, I'm going out. I'm breaking out. I'm gonna disguise Bo. I'm gonna put on a coat. I'm gonna take a walk, and my agents won't know a thing. Don't tell 'em," she joked.

Though she sometimes longs for some of the simpler things in life, Mrs. Obama said her family made a conscious effort to savor the experience when her husband was inaugurated for the second time last month.

"We made a conscious decision to take this in because four years ago, it was a whirlwind," Mrs. Obama said. "This was one of those times where we had to just stop and breathe and appreciate all that we'd accomplished and all that was left to do."

"Watching the girls again walk out, seeing the difference in their ages and sizes and their poise and their stature…I tried to take that in," Mrs. Obama said. "I spent a little more time on the inaugural stage, looking around, turning around, seeing who was there, appreciating the crowd."

At the luncheon following her husband's swearing-in last January, cameras caught her rolling her eyes as she sat between President Obama and House Speaker John Boehner, R-Ohio, but Mrs. Obama said that one instant didn't reflect her overall feeling about the conversation and the luncheon.

"I enjoyed the conversation, had a wonderful time at the lunch. That one shot bore no reflection to how I felt on that day," Mrs. Obama said. "It's difficult to interpret, you know, what's going on in a situation by one shot on a camera…it's not an accurate reflection of anyone's emotions on that day."

As President Obama is urging Congress to pass legislation to curb gun violence in the wake of the massacre at Sandy Hook Elementary school last year, Mrs. Obama said it's important to remember the children who have been lost to gun violence -- such as Hadiya Pendleton, the 15 year old who was shot and killed in Chicago after participating in inaugural festivities last month.

"She was standing out in a park with her friends in a neighborhood blocks away from where my kids...grew up, where our house is. She had just taken a chemistry test. And she was caught in the line of fire because some kids had some automatic weapons they didn't need," she said. "I just don't want to keep disappointing our kids in this country. I want them to know that we put them first. That, you know, our rights and our privileges take a back seat when it comes to the safety of our children in this country."

While the president is pushing for new gun legislation, working to reform the immigration system, and dealing with looming across the board budgets cuts set to take effect next month, Mrs. Obama said he's also learning to cope with his daughters -- Malia, 14, and Sasha, 11 -- growing up as teenagers in the White House.

"There's nothing like the look on his face when Malia dresses up for a party, and she's heading out…she walks past him, and you can see his face sort of just drop a little bit. It's like, 'Who was that?'" she said.

"It remains to be seen how he's gonna handle his daughters growing up, but he's doing fine. So far so good," the first lady said. "He's a little gray…people think the gray is from his job. It's from his children."

The first lady, who turns 50 next year, has said her decision to sport bangs was her "mid-life crisis" and said she's taking some time to get used to the new hairdo.

"My imagination has to be a little more limited, you know? Would I like to skydive? No, can't do that," she said. "Can I drive? I can't drive. So there are a few things I can do, so why not cut my hair, put a little color in it, do a little something?"

"I'm embracing the bangs," Mrs. Obama said. "I hope it's good. My husband likes it. He's really the only one that counts."

Roberts, whose hair fell out during her treatment for MDS, admitted that in December, her stylist picked out a wig for her that resembled the First Lady's haircut. Roberts said she decided not to wear it because "everybody would have thought I was copying you by the time I came back."

"Robin, you are so gorgeous. You are one of the women who can do whatever to your hair and you look great. I wish I could go bald. You look amazing," Mrs. Obama said.

"The wig came out in December," Roberts said.

"See, Robin had it first," the First Lady said. "Robin, I'm following you."

My Plate Recipes like the one cooked by the First Lady, Robin Roberts and Chef Marcus Samuelsson can be found here on Pinterest.