INGRID Moon wants everyone to know how to shop for and prepare real food, rather than relying on convenience foods.
As home economics head teacher at Woolooware High School, she was horrified to see year 7 pupils who couldn't wash up, let alone cook a meal from scratch.
She created a "real food challenge" for students, where they pledge to only eat home-cooked food and avoid junk for a week.
Children are given a diary with information about what to eat and what to avoid, and their choices are signed off by a parent.
Ms Moon said the idea was to avoid the highly processed foods that were now a big part of many people's diets.
"People are busy — they want food quickly but people lack food preparation skills," she said. "It is about being healthy and having the skills to know what to choose.
"We have whole families doing the challenge — it has really taken off. It is really pleasing."