Nutrients for Money: The Relationship between Portion Size, Nutrient Density and Consumer Choices

Overweight and obesity are major risk factors for chronic disease and in the past 40–50 years portion sizes of offered foods, especially energy-dense, nutrient poor varieties, have dramatically increased along with global rates of overweight and obesity. Studies have shown that offering larger portion sizes result in increased food intake, known as the ‘portion size effect’. This is likely due to consumption norms, the expected satiation and satiety of larger portions and the effect of unit bias. In addition, inconsistencies between serving sizes on nutrition information labelling compared to national dietary guidelines, makes it difficult for consumers to estimate and select appropriate portion sizes. Consumers find larger portion sizes more appealing due to their perceived value for money however, the nutritive value of the food is most often not acknowledged. Nutrient profiling models, which classify foods based on their nutrient density per unit cost may help consumers make healthier food choices. This narrative review aims to provide an overview of the portion size effect and discusses the application of nutrient profile score-based labels as a means of promoting nutrient density as value for money to influence consumer choices