Influence of Intrinsic and Extrinsic Food Attributes on Consumers' Acceptance of Reformulated Food Products: a Systematic Review.

Introduction: Reducing the salt, sugar and fat content of food is recognised worldwide as one of the strategies available for reducing the incidence of obesity and non-communicable diseases. The food industry has a major influence on achieving these goals by preserving intrinsic (chemical and sensory properties) and modifying extrinsic (food packaging and other external information) food attributes that can influence purchasing decisions. This article is a literature review of studies that analyse the influence of intrinsic and/or extrinsic attributes on consumer product preference and purchasing decisions.

Methods: A keyword search for relevant studies was conducted using Web of Science, an interdisciplinary electronic resource. Articles from other sources were also included and systematically reviewed.

Results: The search string identified 266 results. Thirty-eight articles were included in the final analysis and coded according to intrinsic and extrinsic food attributes, reformulated nutrient, food category, condition, research methods, consumer response, study location and sample size. There are several authors investigating the effect of intrinsic rather than extrinsic product attributes. Most research deals with processed foods in the category of milk and dairy products, followed by sweetened fruit juices, meat products, sweets and bread. Salt content is the attribute most often reduced, followed by sugar and fat.

Conclusions: Consumers find it hard to swap potential health benefits for hedonic attributes. When evaluating products in expected conditions, they usually rate the reformulated product more highly than the conventional one, while in informed conditions they usually choose the regular product. When products are labelled with a traffic light or nutritional warnings, consumers opt for a reformulated product, even in informed conditions. This review highlights the heterogeneity between food groups, and the fact that many factors influence consumers' product preferences and purchasing decisions. The product should be analysed as a whole and tested in blind, expected and informed conditions, as each individual factor represents a phase of the consumer purchasing decision. The extent of nutrient reduction should be determined by calculating the difference threshold, and the industry should reformulate products gradually based on how consumers detect the reduction.