School lunch has become markedly healthier since more ambitious government standards were implemented in 2012, according to a report released by the Center for Disease Control on Thursday.

In 2014, nearly 80 percent of schools offered at least two vegetables per meal, up from 62 percent in 2000. Canned vegetables are still served, but in far fewer schools. More than half of schools that prepared meals on site used fresh or frozen vegetables instead. For those that still served canned vegetables, 52 percent used low-sodium varieties, up from 10 percent in 2000.

At least two fruits were offered at about 78 percent of schools, up from 68 percent in 2000.

The report also noted that traditional offerings have become healthier. For example, hot dogs often have less fat and are made partly from turkey.

Even snacks have gotten healthier. For example, in the Philadelphia school district, potato chips are baked, not fried; beverages no longer include sweetened teas or sodas; and serving sizes are smaller

The rules, detailed in 2012 by the Department of Agriculture based on a law that passed in 2010, have prompted broad changes in school menus across the United States.

The hope is that changes in school food will lower obesity rates, though pinpointing the reasons for the recent declines has been hard.

Federal health authorities say they plan to release obesity figures for 2014 later this year.