Three years after the federal school lunch program underwent its first major overhaul in three decades, students are eating healthier and wasting less food. For a country awash in obesity, that’s a meaningful step toward helping the youngest generation live longer and healthier lives than their predecessors, once an American birthright that has been lost in a storm of salty, sugary, processed foods.

More must be done to incorporate what we know about nutrition and quality of life into school meals, where many students, particularly those from low-income families, receive much of their sustenance. But it is clear that the improvements made as part of the 2010 Healthy, Hunger-Free Kids Act have schools going in the right direction.

The first year of the new guidelines, passed in 2010 but implemented in 2012, brought criticism from some school lunch directors who said they were seeing more of the new, healthier foods end up in the trash rather than students’ stomachs.

But numerous studies now show that not to be the case. Requirements that every student choose a fruit or vegetable with each meal have significantly increased the amount of fruit eaten by students. Fewer kids are choosing vegetables, but those who do are eating more of them. Overall, fruit and vegetable consumption are up, and food waste is significantly down.

In short, the 32 million students who have school meals every day are eating foods of higher nutritional quality. They are getting more lean protein, whole grains and fiber, and as the preparation and presentation of these foods improve, they are throwing less of their plate away.

Through these improved meals, students are getting more of the nutrients they need to live full lives. And because they eat them every day, they are developing the tastes and habits needed to make nutrition a permanent part of their lives.

It cannot be overstated how importance that change is. In the U.S., 40 percent of women and 35 percent of men are now obese, up from 16 percent of adults in the early 1980s. Twenty-one percent of adolescents are obese.

As a result, stroke, chronic liver disease, heart disease and diabetes are rampant. If nothing is done, today’s children will live less healthy lives, and possibly shorter ones, than their parents, despite the vast improvement in what is known about living well. All the medical advancements over the last 30 years are no match for the prevailing American diet.

The improvement in school meals, where low-income students get as much as half of their calories, shows there is hope. Schools must continue to improve the quality and taste of meals. Maine schools should take advantage of the boom in local agriculture to serve students healthy, tasty meals (some, including Portland, already have). They also should continue to push students to try new things — a luxury poor students don’t have at home.

And Congress needs to continue to guard the community eligibility provision, which makes it simple for schools to offer meals to more students. Despite its unquestionable success, the provision, much like food stamps, has its detractors.

Good nutrition is the foundation for successful, happy, healthy lives. Under the new guidelines, schools are doing better than ever at providing that nutrition, and we shouldn’t take a step back now.