For these types of systemic issues, he said, public policy has to change. To fight the childhood obesity epidemic, such initiatives as removing soda and junk food from schools, requiring physical education in schools and afterschool programs, and redesigning neighborhoods to encourage walking, biking and playing are necessary.
Adults lay down the trajectory of their health in childhood, said Dr. Michael Rosenbaum, pediatrician and co-director of the Naomi Berrie Diabetes Center at Columbia University.
"The heart attack or stroke that one has at age 50 is in most cases somewhat of a reflection of every moment that one ate, slept, smoked, and exercised -- or didn't exercise -- before then," he said.
Some of the damage done early on, such as the buildup of plaque in the arteries, isn't reversible, Stettler said, so changing our eating and exercising culture needs to happen early.
"We shouldn't ignore things that we can influence today," Stettler said. "We should address them now, which is why Michelle Obama's new initiative is very important."
The first lady's "Let's Move" campaign to curb childhood obesity is an effort to address these endemic forces on a societal level.
"We want to eliminate this problem of childhood obesity in a generation," the first lady told "Good Morning America's" Robin Roberts Tuesday. "We want our kids to face a different and more optimistic future in terms of their lifespan."