Protocol for a Randomized Trial Assessing Consumer Evaluations of Pre-Packaged Foods that Systematically Vary by Nutrition Information and Product Attributes

Background: Nutrition information is increasingly provided on pre-packaged foods as a public health measure to help consumers make healthier food choices. Many studies have looked at the independent effects of three main sources of nutrition information: the Nutrition Information Panel (NIP), front-of-pack labels and health claims. However, few studies have considered their interactive effects. A better understanding of how these different sources of nutrition information interact with each other is important given they frequently appear together on food packs. There are also policy implications since many countries specifically mandate the provision of an NIP whenever a health claim is made. Methods: This paper outlines a protocol for an experimental study assessing how nutrition information (FoPLs, health claims and NIP), in combination with food type, price and product healthiness interact to affect consumers' product evaluations. Consumers' global impressions, perceptions of healthiness, purchase intentions and assumptions relating to the amount of the product that is appropriate/desirable to consume will be assessed. The nutrition information presented will include NIPs, front-of-pack labels (Daily Intake Guide, Multiple Traffic Light system, Health Star Rating system) and health claims (nutrient content, general level, higher level). A diverse sample of approximately 2000 Australians will be recruited to complete an online survey that will require them to evaluate a range of hypothetical products with varying nutrition and price attributes. All attribute levels will be fully crossed with each other, resulting in a full factorial design. This design has not been used in past studies and offers a higher level of control than achieved previously due to the ability to explore interactions between all attribute levels. Discussion: Study results will indicate (1) the independent and combined effects of each attribute on consumer evaluations, (2) which front-of-pack labels are more effective at helping consumers distinguish between healthier and less healthy foods and (3) how health claims affect perceptions of healthiness. The study will also provide crucial information on the effectiveness of the new Health Star Rating system, for which quantitative research is currently lacking.