Extent of alignment between the Australian Dietary Guidelines and the NOVA classification system across the...

The Australian Dietary Guidelines are currently being revised and ultra-processed foods have been identified as a high priority action area. To better understand how well the current Dietary Guidelines align with level of processing classifications, the aim of this study was to assess the alignment between the Australian Dietary Guidelines and the NOVA classification system for classifying the healthiness of packaged foods.

Data were sourced from the Australian FoodSwitch dataset, which included 28 071 packaged food and beverage products available in major Australian supermarkets in 2022. Products were classified as (i) core or discretionary (Australian Dietary Guidelines) and (ii) non-ultra-processed or ultra-processed (NOVA). Agreement between the two systems (core vs. non-ultra-processed and discretionary vs. ultra-processed) was evaluated using the kappa statistic.

There was 'moderate' agreement (κ = 0.41, 95% CI: 0.40-0.42) between the Australian Dietary Guidelines and the NOVA system, with 69.8% of products aligned across the two systems. Alignment was more common for discretionary foods (80.6% were ultra-processed) than core foods (59.9% aligned were not-ultra-processed). Food categories exhibiting the strongest levels of alignment included confectionary, foods for specific dietary use, and egg and egg products. Discordance was most common for convenience foods, sugars, honey and related products, and cereal and grain products.

Despite moderate alignment between the Australian Dietary Guidelines and NOVA, the discordance observed for almost one-third of products highlights the opportunity to develop recommendations for ultra-processed foods within the guidelines to advise Australians how these foods should be considered as part of a healthy diet.