Diff'rent Strokes (1978)

S3E13 Junk Food Junkie (a.k.a.) Junk Food

After Arnold receives disheartening news from his dentist, his world gets more complicated when Drummond's sister, Sophia, who is passionate about healthy eating, pays a visit. Inspired by her, Drummond decides to push for the removal of vending machines filled with unhealthy snacks at Arnold's school. However, Arnold is torn, as his aspirations for class president might hinge on the continued presence of those very machines.