The Healthy, Hunger-Free Kids Act signals a significant change in how we invest in our children and their health. Thanks to the tireless efforts of thousands of people who are working hard to get America’s schools to serve healthier food, including First Lady Michelle Obama, the $4.5 billion “Healthy, Hunger-free Kids Act 2010” prevailed in the lame-duck session of Congress, and is being signed into law by President Obama today. The new law marks a key step toward potentially transforming the food served in America’s public schools.

Here’s why. It reduces the administrative burden on schools by authorizing the automatic enrollment of kids who are eligible for free lunch. It will help rid our schools of junk food. It boosts the bare-bones food service budgets that prevail across the country by six cents per meal, so schools can add healthier options. And it provides grant funds for starting “Farm to School” programs, which have been legislatively approved, but denied funding by Congress since 2004.

Take the junk food provision. Long emblematic of the mixed messages that pervade the school food environment, vending machines with junk food first became available in all schools in 1972. “Candy, soft drinks, and snacks are part of real life,” a representative of a Coca Cola bottler from Rhinelander, Wisconsin exclaimed about their push for sodas in vending machines.

In 2002, the Los Angeles Unified School District banned sodas from vending machines, due to a brilliant organizing campaign by school food advocates and youth. Three years later, Los Angeles barred junk food from its schools, too. The new legislation establishes nutritional standards that will get junk food out of schools altogether, not just their cafeterias.

Sure, the six-cent boost is extremely modest and far less than ideal. But it marks the first time in 30 years that schools have been able to spend more on our kids’ lunches. The current rate is $2.72, and the only other increases have been brought on by inflation indexing.

More significantly, the law will bring more sanity to the way school districts price meals. The reimbursements for low-income students will no longer subsidize the price for meals of wealthier students. Simply put, there will be more money available to include healthier meal options on the school menu.

The legislation also makes it easier for school districts to account for students eligible for free and reduced–price lunch and breakfast. That reduces the burden on parents who previously needed to fill out extensive paperwork to qualify.

The Farm to School program now operates in thousands of school districts in all 50 states and the District of Columbia. The Farm to School approach enables schools to purchase food from local and regional farmers to provide healthy, local, and tasty offerings in the school cafeteria. It also calls for planting school gardens that give students firsthand experience with growing and tasting food, and understanding where food comes from.