To evaluate the trends in the healthiness of packaged food purchases of Australian consumers before and after the introduction of the Health Star Rating (HSR) nutrition labels.

Panel data analysis and difference-in-differences analysis.

The Australian Government endorsed HSR nutrition labels for voluntary implementation on packaged foods in June 2014. We analyse the packaged food purchases of households across all major supermarkets before (January 2014 to June 2014) and after (June 2014–Dec 2018) the introduction of HSR.

6284 members of a panel of households across Australia reporting their grocery purchases to a market research company (Nielsen Homescan panel).

The healthiness of household food purchases exhibited a U-shaped trend – decreasing from 2014 to 2017, and then increasing from 2018, corresponding to the time when a higher proportion of products were HSR-labelled. Households that purchased a higher proportion of HSR-labelled products had healthier household purchases overall. Further, the healthiness of households’ category-specific food purchases was positively associated with the proportion of HSR-labelled products in categories where HSR was adopted, relative to control categories where HSR was not adopted.

In Australia, once a substantial number of packaged food products adopted the voluntary HSR summary indicator, we observed an increasing trend in the healthiness of household food purchases. Widespread adoption of a nutrition summary indicator, such as HSR, on packaged food is likely to be beneficial for population health.

To examine the impact of front-of-package (FOP) labels on perceived healthfulness, purchasing intentions and understanding of common FOP systems.

A parallel, open-label design randomised participants to different FOP labelling conditions: ‘high in’ warning labels (WL), multiple traffic light labelling (TLL), health star ratings (HSR) (all displayed per serving) or control with no interpretive FOP labelling. Participants completed a brief educational session via a smartphone application and two experimental tasks. In Task 1, participants viewed healthy or unhealthy versions of four products and rated healthiness and purchasing intention on a seven-point Likert-type scale. In Task 2, participants ranked three sets of five products from healthiest to least healthy.

Online commercial panel.

Canadian residents ≥ 18 years who were involved in household grocery shopping, owned a smartphone and met minimum screen requirements.

Data from 1997 participants (n 500/condition) were analysed. Task 1: across most product categories, the TLL and HSR increased perceived healthiness of healthier products. All FOP systems decreased perceived healthiness of less healthy products. Similar, albeit dampened, effects were seen regarding purchasing intentions. Task 2: participants performed best in the HSR, followed by the TLL, WL and control conditions. Lower health literacy was associated with higher perceived healthiness and purchasing intentions and poorer ranking task performance across all conditions.

All FOP labelling systems, after a brief educational session, improved task performance across a wide spectrum of foods. This effect differed depending on the nutritional quality of the products and the information communicated on labels.

Trial Registration: NCT03290118.