President signs Michelle Obama-backed childhood nutrition act into law

President Obama signed the first lady's childhood nutrition bill into law Monday.

Obama, joined by Michelle ObamaMichelle LeVaughn Robinson ObamaAl Sharpton: Royal wedding shows white supremacy is ‘on its last breath' Meghan Markle's pre-royal 'finishing lessons' and an etiquette of equality Place your royal wedding bets: Website offers odds on surprise American guests MORE at Harriet Tubman Elementary School in Washington, hailed the legislation as "vitally important to the health and welfare of our kids and to our country."

The Healthy, Hunger-Free Kids Act is a $4.5 billion plan that expands free lunches and makes school lunches more nutritious.

Healthy eating and combating obesity are some of Michelle Obama's signature issues.

The president joked that had he failed to pass the bill, the first lady would have punished him.

"Had I not been able to get this bill passed, I would be sleeping on the couch," Obama said.

The first lady responded: "We won't go into that. Let's just say it got done, so we don't have to go down that road."

Obama noted that doctors are seeing increases in diabetes and hepatitis in children because of higher rates of obesity and poor eating habits.

"These are things that they only used to see in adults," Obama said. "And this bill is about reversing that trend and giving our kids the healthy future they deserve."

Michelle Obama spoke at length about the importance of the legislation, applauding expanded access for free, nutritious meals for the country's children.

"We can all agree that in the United States of America, no child should go to school hungry," Michelle Obama said.