Hopkins School freshman Sophie Sonnenfeld, 15, had an awakening over chicken fingers.

Sophie, a Branford resident, said shebegan to reevaluate her diet when, in the third-grade, she realized chicken fingers weren’t actually chicken’s fingers. It spurred her interest in evaluating what she eats more closely, and now she does not eat red meat.

At her school, Sophie is an ambassador for Meatless Mondays, a campaign run by The Monday Campaigns, a nonprofit initiative associated with Johns Hopkins, Columbia and Syracuse universities that encourages people to commit to making healthier choices on Mondays. In addition to going meatless, the initiative runs campaigns for doing things on Mondays such as exercise, quitting smoking and promoting sexual health.

“It’s not something forced upon them,” Sophie said. “You really have to have conversations with students.”

Alongside student Jack Kealey, a 14-year-old from Bethany who keeps a vegan diet, Sophie spends her Monday lunch period outside the cafeteria with a clipboard. Students are welcome to sign their names to take a pledge not to eat meat that day.

Jack said there are three main positive health factors to reducing meat consumption: animal welfare, environmental health and dietary health.

“Many people only think of one aspect,” he said.

Sophie, who first began as an ambassador for the campaign when she attended New Haven’s Foote School, said her organizing skills and confidence have grown as she’s continued to run the campaign. She said it took her a while to work up the confidence to speak to student athletes, but she’s become comfortable discussing protein alternatives like tofu with people with whom she doesn’t immediately relate.

Hopkins seventh-grader Sam Cherry, from Westport, said he participates in the campaign some weeks, but he wonders why the campaign runs on Mondays only.

According to The Monday Campaign’s website, that reason is because of the periodicity involved in choosing a day such as Monday and how people are likely to set weekly intentions on the first day of the workweek.

Rhea Ahuja, a seventh-grader from Trumbull, said she does not eat meat for religious reasons. On Mondays, she said the campaign makes her less of an anomaly in the lunchroom.

Nate Stratton, a junior who lives in New Haven, said the meatless option would be more popular among students if the cafeteria would offer more appetizing options.

“We’d all love Meatless Monday if they did it a little better,” he said.

Going meatless one day a week wouldn’t be a dramatic change for him, he said, given there isn’t a lot of meat at home.

“My mom is a vegetarian. My dad is a vegetarian. My whole family is vegetarian. I’m the only meat eater.”

Jack said representing the program has had a domino effect: As they begin to reach their fellow students, they become ambassadors themselves and it spreads to the school. About two dozen names appeared on Jack and Sophie’s pledge forms.

Linda Weber, communications director for Hopkins, said the school’s menu is devised to provide options for all students.

“Hopkins’ dining program prepares a variety of nutritional menu choices — both meat and vegetarian — for students to choose from each day,” she said in an email.

Last week, the menu featured two vegetarian soups and arroz con pollo (chicken cooked with rice, onions, garlic, and tomatoes), alongside a deli bar, a salad bar and a pasta bar.

Currently, Meatless Mondays has a presence at Hopkins, Foote School, Choate Rosemary Hall and Hamden Public Schools. Sophie said that last Monday was the first day ambassadors ran the program at Metropolitan Business Academy in New Haven.