I like fiction. I even know some talented people who make money composing it. But as a nonfiction writer, when I go into schools, I am sad that the books students choose to read are almost always fiction.

A child thinks: Nonfiction? You mean textbooks. Ugh.

That’s supposed to be changing. The Common Core State Standards, which have had a marked effect on teaching lately, say nonfiction is essential. Children need a steady diet of it to accumulate the background knowledge that will allow them to recognize more words as they learn to read.

One of the nation’s most successful literacy efforts, the Accelerated Reader program, has embraced the move toward nonfiction in the third of U.S. schools it serves. Students read books and other material, then take short tests to gauge comprehension. The program began 34 years ago when Judi Paul, with her husband, Terry, started Renaissance Learning. It is based on a system she invented on their kitchen table in Port Edwards, Wis., to motivate their children to read.

I grabbed the company’s annual “What Kids Are Reading” report to identify the most popular books and thus win respect as a grandpa gift-giver. Would our three grandsons like nonfiction? I wasn’t sure. They told me they had never read anything like that.

Instead, they love books based on the Minecraft video games and Rick Riordan’s tales of teenage demigod Percy Jackson. The second-grader is not yet clear on the distinction between those stories and real history or science. “Some of Percy Jackson is fiction, but most of it is nonfiction,” he insisted.

Gene Kerns, the chief academic officer at Renaissance, showed me data indicating that nonfiction had risen from 11 percent in 2003 to 25 percent this year of all the materials its students read. But nonfiction is still almost entirely missing from its lists of the top 20 books in each grade.

There is no nonfiction in the top-20 lists from kindergarten through third grade. (Books are often read to students that age.) The only nonfiction books on the fourth-, fifth- and sixth-grade top-20 lists are cartoonist Raina Telgemeier’s accounts of her adolescence in “Smile,” “Sisters” and “Guts.” Elie Wiesel’s classic memoir “Night,” about being a teenage prisoner at Auschwitz and Buchenwald, was the only nonfiction book on the eighth-, ninth-, 10th- and 12th-grade lists. It was joined on the 11th-grade list by Frederick Douglass’s 1845 narrative of his life in slavery.

The lists identify many nonfiction books that did well but didn’t make the top 20. Publishers sometimes seemed desperate to attract young readers with titles such as “Why Rabbits Eat Poop and Other Gross Facts About Pets” (third grade), “Take Your Pick of Disgusting Foods” (sixth grade) and “The Most Disgusting Animals on the Planet” (ninth grade). More common were titles such as “The Right to Learn: Malala Yousafzai’s Story” (fourth grade), “Rosa Parks and the Montgomery Bus Boycott” (fifth grade) and “Muhammad Ali: American Champion” (10th grade).

Mary Brown, a reading specialist in Duncan Falls, Ohio, said in the annual report that nonfiction is “key for children with limited experiences or exposure to the external world.”

But getting them to read it takes work. In its early years, Accelerated Reader suggested letting children choose what to read from lists pegged to their level. These days, the company tries harder to encourage nonfiction and make it available.

Kerns said, “In schools where there is no central library and only classroom libraries, those tend to be heavy on fiction.” To fill that gap, Renaissance Learning has a digital reading platform, myON, that is 70 percent nonfiction.

Always high on the annual lists are big-name fiction authors whose books I see scattered about my grandsons’ house: Dr. Seuss, Mo Willems, E.B. White, Jeff Kinney, JK Rowling, Judy Blume and my personal favorite, Dav Pilkey. He wrote several novels about superhero Captain Underpants and co-wrote the resulting film, which I seriously consider a cinematic masterpiece.

I have ordered some nonfiction to put under the boys’ Christmas tree. I have hopes they will read the books, based on my observations of their eating habits. I used to require they consume at least two carrots before they could have dessert at our house. As a result, the second-grader now regularly demands carrots, thinking that will pre-qualify him for any sweets.

I’m not sure I approve of promoting nonfiction as the equivalent of eating your root vegetables. But there is nothing wrong with inspiring good habits. We nonfiction writers need all the help we can get.