"The nuclear family spent 40 per cent of their disposable income on food, the single adult male spent 75 per cent and the single mum spent 30 per cent."
Some gluten-free items cost up to five times more than regular ingredients. Gluten-free wraps were 316 per cent more expensive and flour was 574 per cent more costly.
"It's really a very expensive diet to follow," Ms Lambert said.
"For people who have coeliac disease [about one per cent of the population] they need to follow this diet for medical reasons. They have no alternative - they have to spend that money.
"I can understand how they would become irritated by people who eat gluten-free foods but don't need to."
A recent study by Allied Master Chemists of Australia Limited found one in four Australians between the ages of 25 and 34 consume only gluten-free meals, but only a small percentage of those suffer from coeliac disease or a gluten intolerance.
- news.com.au