School lunch is part of the problem with both child hunger and childhood obesity. It can be part of the solution too.

Unfortunately, after some leaps in the right direction, the Trump administration earlier this month took a step back.

The U.S. Department of Agriculture announced that it is moving officially to loosen some of the restrictions put on unhealthy school meals by the Obama administration. As a result, meals will have fewer whole grains and more sodium and saturated fat.

The changes, at this point, are not catastrophic. But schools will soon have less pressure to serve healthy food, and manufacturers will have less of a reason to produce healthy products for schools. As a result, kids will get more of the nutrition-deficient processed food that over a lifetime causes serious health problems.

The USDA, which has targeted the Obama-era regulations since early in President Trump’s term, says the rollback is necessary to help school lunch programs, which they say have seen fewer kids buying school lunch and more food going wasted since the more stringent requirements were put in place.

School revenues may have been off at the beginning, but they’ve rebounded, studies show, and participation in school programs actually has increased among children who are eligible for free or reduced-price meals.

And despite what USDA secretary Sonny Perdue says, food waste has stayed largely flat. Research even shows that students are now eating significantly more vegetables and that more students are taking fruit with lunch.

Perdue has been influenced largely by the School Nutrition Association, a group that includes not only school meal coordinators but also PepsiCo, Kraft Heinz, and almost every other major purveyor of processed food. And while it’s true that some school districts have balked at the changes made by the Obama administration, it’s hard not to see the USDA’s actions through that lense.

For all the SNA’s complaints about discarded wheat biscuits, only 15 percent of schools had asked for a waiver from rules requiring whole grains. And almost every district had met the first phase of lower sodium guidelines and was in line to meet the second round too, until the USDA moved the deadline back two years — and eliminated further planned reductions.

School districts were rising to the challenge presented by the Obama-era regulations, and as a result students’ diets were slowly, incrementally changing. Some districts were struggling at the change — as some always will — but others were running with it, including some in Maine that have added lots of local food to the menu.

In fact, some Maine schools say they will keep the healthier menu.

Good. School meals should not be full of calories and empty of nutrients, as was largely the rule in the past — and schools throughout the country have shown that to be possible, even with budget restrictions.

And more kids should be eating those meals too. Many students eligible for reduced-price meals do not take advantage, for a number of reasons, including the stigma of getting a free meal. Cities around the country — including Boston and New York, and some districts in Maine — have used the USDA’s Community Eligibility Provision to extend free school meals to all students, lowering administration costs and student hunger at once.

If Perdue wants to improve school lunch, he should start by pushing more schools to use the provision, and he should provide more resources for initiatives like the Farm to School program, which puts locally grown food in schools.

Those would be two small steps toward solving child hunger and childhood obesity. Taking healthy foods out of school? That’s no solution at all.