New research analysing hundreds of international studies into the efficacy of nutrition labelling has shown it is largely ineffective at preventing people choosing unhealthy processed food, unless large graphic warning labels are used on the front of packaging.
The research paper, published in the Journal of Public Policy and Marketing, found that stop sign warning labels - used on foods high in sugar or fat in some countries including Chile, Peru and Israel - had the largest impact on consumption.
Deakin University Professor of Marketing Chris Dubelaar, a co-author of the paper, said this was consistent with previous research identifying that public awareness campaigns using warning signs should emphasise the negative consequences of excess consumption of fat, sugar and sodium for the largest effect.
Professor Dubelaar said other types of 'lighter touch' food labelling systems - including the 'Health Star Rating' used in Australia - were only found to have some effect in encouraging people to buy more healthier foods. But were not effective in stopping people purchasing unhealthy items.
"A basic food label that tells you something is not good for you doesn't work, people ignore it. Unless it has a big warning label on the front of that pack that explicitly says, 'this is going to hurt you', people will ignore it," he said.
"But telling people something is good for them, that's a different story. They will listen to that. Our research confirms that a promotion approach works better than a prevention approach."
The research - co-authored by academics at Deakin, University Technology Sydney (UTS), Bond University and ESADE Business School in Spain - analysed 23 different meta-analyses of nutrition labelling efficacy research between 2016 and 2021. These drew from the results of hundreds of studies involving more than a million people worldwide.
It shows food labels framed to encourage consumers to eat more of healthier food items are, in general, more likely to influence consumers than interventions which are framed to discourage consumers from eating unhealthy food.
Lead author UTS Associate Professor Natalina Zlatevska said it was critical Australia made effective food labelling mandatory.
"We need to make it very clear when food is bad for you," Associate Professor Zlatevska said.
"This is part of a bigger issue around health literacy. Most food labels have too much information that is hard for people to decipher. Complex labels don't work that well because people don't understand them.
"Obesity is a global public health crisis and post-pandemic obesity levels are at record highs. We need to help people make a better decision about their food choices. The current labels don't work, and evidence-backed action is needed now."
