Ugh, middle school.

There’s awkwardness, cliques and bullying. The challenges of preadolescence. Low-self esteem, or maybe too much self-esteem.

It can all collide in the cafeteria and leave some kids feeling invisible if they don’t fit in at any one particular table.

What difference could it make if students themselves tried to encourage a change in the lunchroom?

That’s the idea behind a national campaign called No One Eats Alone Day, a student-led program that takes aim at social isolation among middle schoolers.

Schools are picking up on the idea. More than 300,000 students across the country signed up. Participation grew from 35 schools in 2014 to more than 700 this year.

The program was created by Beyond Differences, a national nonprofit group whose mission is to change the culture in middle schools to be more inclusive.

With social isolation and bullying now a chronic problem in schools, this program seeks to reverse these trends by asking students to engage in simple and fun ways to include others during lunchtime — making sure no one eats alone, said Beyond Differences founder Laura Talmus.

Middle school was rough for Talmus’ daughter, Lili Smith. Lili was born with cranial facial syndrome.

“She would call me almost daily — ‘Mom, I have nobody to eat with, and the girls don’t want me to sit with them,’ ” Talmus said. Her daughter would finish lunch and call her from the restroom, crying. “Lili was never teased or bullied, but was almost suffering as much because she felt invisible.”

Lili died at age 15 from medical complications of her syndrome. Afterward, a group of teens from the community banded together to bring change to their local schools.

At Rogers Middle School in Affton, Mo., resistance to No One Eats Alone Day began after students learned of it through the morning announcements. The student organizers heard that a lot of students were worried that they wouldn’t get to sit next to their friends.

Student members of the school’s anti-bullying team placed conversation starters on the tables in their cafeteria. Questions like, “Who is your favorite celeb?” and “Who is your role model?”

The students waited with pieces of paper to hand out to classmates, color-coded to randomly assign them to tables. When the lunch bell rang, there was audible disappointment among friends who were separated. Some tried to make the best of what was an uncomfortable situation.

“I would much rather sit alone than with people I don’t know, to be honest,” said Cori Caby, a seventh-grader.

No one expected the kids to be best friends after one lunch.

It was more about being aware of other people’s feelings, and encouraging students to start a conversation with someone they normally don’t talk to, said Reece Black, an eighth-grader and one of the organizers.

Sixth-graders Jenna Walden and Avarry Wilkerson ended up at a table by themselves, and they noticed that Alexander Scherer, a new student, was alone. They moved over to sit with him. As he ate, he and the girls talked. “By the way, I’m Avarry,” she said as lunch was wrapping up.