CHOICE has long believed that %DI labels are confusing and require consumers to undertake complex calculations to use the information effectively, and this was confirmed by the independent panel that reported to Australian governments on food labelling in January 2011.
However, this research shows that even if consumers could understand the information on %DI labels, the inconsistent serving sizes on which they are based means they fail to help shoppers compare products.
All products analysed in the survey were available on supermarket shelves in September and October this year.
In most categories examined there was a wide range of serving sizes for similar products. All food categories (with the exception of the chilled soup product type) had inconsistent serving sizes and in the most extreme case, the maximum serving size of flavoured and fruit based yoghurts was ten times greater than the minimum.
Products with %DI didn't show any greater consistency in serving size than those without. In some product categories, the research found that the average serving size was lower for products with %DI than products without.
Corn chips, most breakfast cereals, chilled ready meals and canned soup all recorded significantly lower serving sizes for products with %DI labels. However, the opposite finding resulted from analysis of extruded snacks, frozen ready meals and yoghurt.
What is clear from this research is that vast differences in serving sizes occur across the board and the voluntary adoption of the %DI system by the food industry has not provided consumers with the consistency they need in order to make healthy decisions.
Within the snack food category, data for 337 products was analysed across eight product types, including corn chips, popcorn and wholegrain chips.
- Of 40 corn chip products, serving sizes ranged significantly, with a minimum serving size of 25g and a maximum of 100g.
- Similarly, 32 popcorn products produced an 87g difference between the minimum (13g) and the maximum (100g).
- Potato crisps - the most popular snack food product on record, with 101 products – also produced a significant range between the minimum 19g and maximum 50g serving size.
- Within the snack food category, it was interesting to note that similar products from the same brand varied their serving sizes. For example, Coles Organic Sweet and Salty Popcorn recommended a serving size of just 20g, while Coles Butter Microwave Popcorn had a serving size of 100g.
In the ready meal category, frozen ready meals, also a popular product with 172 labels, proved to be the most difficult to compare, with the maximum serving size (450g) almost four times that of the minimum (115g). Serving sizes also varied greatly within the well-known brands. For example Lean Cuisine Classic Beef Stroganoff with Pasta and McCain Healthy Choice Chinese Chicken and Cashew had a 280g serving size, while Lean Cuisine Rich Beef Lasagne was 400g/serve and McCain Healthy Choice Honey Stir-fry Chicken was 420g/serve.
The variation continued in the ready- to-eat breakfast cereal category. The 33 plain adult cereal products surveyed produced a five-fold range between the minimum 10g and maximum 55g serving sizes. Of 110 muesli products, Whisk & Pin Summer Muesli set their serving size at 80g, while the minimum in this category was just 25g.
The only exception to the trend of wide ranging serving sizes was in the chilled soups product category, where 22 products all set the serving size at 300g.
The findings in the George Institute’s new report are consistent with the results of research conducted in 2009 by CHOICE in collaboration with public health groups, including the Cancer Council, which found that %DI labels were not as easy to interpret as traffic light labelling.
While the 790 consumers surveyed initially thought that %DI labelling was easy to use, only 64% of consumers chose the healthier option when using the monochrome %DI table currently used on packaging.
In contrast, 84% could correctly identify the healthier option when using the front-of-pack traffic light system.