How Much Could Health Star Rating Labels Improve Diet in New Zealand?

Abstract

Background: Chronic diseases such as obesity, hypertension, and cardiovascular disease are pressing public health problems worldwide. In New Zealand (NZ), one in three adults is obese (31%) and 35% of adults are considered overweight. To promote healthy eating and decrease chronic diseases, front-on-pack (FOP) nutrition labelling schemes such as the health star rating (HSR) system may be useful. However, there is little evidence concerning the impact of FOP labelling schemes on nutrients, food categories and products, and nutrition in general. Aim: To investigate the potential of the new HSR FOP nutrition labelling scheme to improve NZ population diet by simulating the replacement of usual packaged food purchases with the healthiest available choices based on the HSR system. Methods: A systematic review was carried out examining studies in one or more variations of the FOP label, either in the research space, outside a supermarket space, or on-line, and comparing the responses from the experimental conditions for a wide range of outcomes. This research used baseline (one-week period) food purchase data from a large NZ trial to estimate the maximum potential impact of the HSR system on diets in a sample of 250 adults aged 18+. The simulation involved replacing packaged food products purchased with the healthiest alternative product, which was identified using the HSR system. Nutrients analysed were energy, protein, fibre, saturated fat, sodium and sugar. Statistical inference was applied to the data and Microsoft Office Excel 2010 and Minitab 17 were used to make statistical calculations. Results: After replacement, it was observed an increase in positive nutrients such as fibre (median: 46.7%) and protein (median: 47.5%), and a decrease in negative nutrients such as saturated fat (median: 390.6%), sodium (median: 237.4%), total sugars (median: 176.2 %) and energy (median: 28.36%). Conclusion: This research provides estimates of potential positive impacts of the HSR system on NZ diets by simulating the replacement of commonly purchased food products with the healthiest choice possible. Positive results were obtained on a variety of nutrients for a large sample of participants, and for a number of food categories and products. Further research could involve real-world studies.