From NBC's Athena Jones
President Obama signed the Healthy, Hunger-Free Kids Act of 2010 on Monday, calling it "vitally important" to the country. He was joined by the first lady, perhaps the bill's biggest booster

The law reauthorizes child nutrition programs for five years and includes $4.5 billion over 10 years for the programs. It strengthens school meal programs by increasing the number of students who are eligible to get free meals -- adding about 115,000 students to those rolls -- and by improving the quality of the food provided.

Combatting childhood obesity through better nutrition and exercise has been one of the first lady's key initiatives and something she has devoted a great deal of time to through her Let's Move campaign and her White House garden. The new law is aimed at helping reach the goal set she of solving the problem of childhood obesity within a generation.

The first lady noted the groundswell of support from parents, schools, doctors and business and labor leaders, saying the nearly $150 billion spent each year to treat obesity-related illnesses -- conditions like type 2 diabetes, high blood pressure and high cholesterol that are increasingly being seen in the nation's youth -- had an impact on the nation's economy. With a third of American young people overweight or obese, she said the problem was more than a public health issue.

"When more than one in four young people are unqualified for military service because of their weight, they (military leaders) tell us that childhood obesity isn't just a public health issue, they tell is it not just an economic threat, it is a national security threat as well," she told the audience at Harriet Tubman Elementary School.

President Obama also talked about the economic impact of treating obesity-related diseases and he noted that the bill passed with strong support from both parties.

"That hasn't happened as often as we've liked over the last couple of years, but I think it says something about our politics," the president said. "It reminds us that no matter what people may hear about how divided things are in Washington, we can still come together and agree on issues that matter for our children's future and for our future as a nation."

Agriculture Secretary Tom Vilsack, Health and Human Services Secretary Kathleen Sebelius and Education Secretary Arne Duncan were also on hand for the event, along with House Speaker Nancy Pelosi (D-CA), Sens. Blanche Lincoln (D-AR) and Tom Harkin (D-IA), Reps. George Miller (D-CA), Rosa DeLauro (D-CT) and Todd Platts (R-PA)

Administration officials touted the bill in a conference call with reporters on Friday, with Vilsack calling it a "historic investment" and said today's signing one of the most significant days in child nutrition since President Harry Truman signed the School Lunch Act in 1946.

More than 31 million students receive school meals, according to the administration. Under the bill, schools will be provided with funds -- through the Department of Agriculture -- to update their nutritional standards for federally subsidized lunches. Vilsack said the 6-cent boost in the rate of reimbursement to schools represented the first real rate increase in over 30 years. The new law also gives the USDA authority to set nutritional standards for all foods sold at schools in vending machines, lunch lines and school stores, sets goals for the amount of physical activity students should get and helps communities establish local farm-to-school networks and create school gardens.

The bill is paid for in part by rolling back a temporary increase in food stamp benefits starting in the fall of 2013 -- something that angered some members of Congress -- and the president said he was committed to working with them to restore those funds in the future.