In some states physical education is not mandatory for students. In Florida, where state law requires elementary and middle-school students to participate in physical education classes, a waiver option allowed thousands of students to opt out.
"When we were growing up it wasn't a choice," Obama said. "It wasn't either learn how to read or you learn how to run. We did both. ... And there are schools, even without additional funding, that are figuring out ways to do it."
The first lady said she can relate to everyday families when it comes to the stresses of life and the effort it takes to eat healthy.
"Even though I live in the White House today, and I've got a lot of help ... I still relate to the stress and the challenge of doing what you know is the best thing for your child.
"And parents are hitting up against a brick wall, again, trying to make it all work -- hold down a job, get kids to activities, cover homework, get them to extracurriculars and then let's shop and cook for meals?"
To help parents, the first lady said she's working with the Food and Drug Administration and major food manufacturers and retailers to make it easier for parents to identify healthier foods by placing nutrition labeling on the front of the package.
Also, Obama wants to work with local mayors and governors to create a "tailored approach" to getting their citizens healthier based on the challenges each community faces. The American Academy of Pediatricians is partnering with the government to educate pediatricians to work more closely with families when it comes to weight.
Obama doesn't expect families to make drastic changes, only to balance indulgences with healthy options.
"I love burgers and fries, you know? And I love ice cream and cake. So do most kids. We're not talking about a lifestyle that excludes all that. That's the fun of being a kid. That's the fun of being a human," Obama said.
ABC News' Sunlen Miller contributed to this report.