Understanding food labelling, avoiding genetically modified food, and choosing New Zealand-made products, were all on the Green Party MP's shopping list.
Guiding 15 people for an hour around the aisles of Centre City New World, Ms Kedgley said food labelling was poor in New Zealand, with labels often leaving out the most important information.
"We often don't know what we are buying.
''You feel like you need a degree in chemistry to understand it all."
Using garlic as an example, Ms Kedgley said cheap Chinese products had flooded into the country and decimated the local industry.
"If we are not careful we will do to our food industry what we have done to our manufacturing. "If we don't support local growers soon we will find there is no New Zealand garlic left."
Ms Kedgley said shopping smart at the supermarket was a form of health insurance for the future and people should resist specials on junk food.
Guiding the group to the breakfast cereal aisle, Ms Kedgley declared her love of rolled oats produced by Dunedin company Harraways, but she became a cereal killer of any sugar-laden product marketed at children.
"This is just confectionery . . . it is 40% sugar," she said.
While shopping her way could add extra dollars to already stretched budgets, Ms Kedgley said it was worth it to support New Zealand products.
