The energy density (ED, kcal/g) of food is widely believed to predict palatability. However, Chapter 2 describes a study showing significant cultural differences in the relationship between food preference and ED. Additionally, within a single culture, this relationship differs across low and high ED foods. Low ED foods are mainly fruit and vegetables, and public health messaging promotes their health benefits. Both children and adults appear to prefer those with high ED. However, it remains unclear whether this is observed in fruit and vegetables when investigated separately. Moreover, some argue that sweetness indicates the energy content of foods and thus might also play a role in determining food preference. Accordingly, Chapter 3 reports a study exploring the relationship between food preference and ED and sweetness in (culinary) fruit and vegetables, respectively, and conducted cross-cultural comparisons between the UK and China. In Chapters 4 (the UK) and 5 (China), fruit and vegetables were classified into three groups according to their culinary use and botanical origin: culinary fruits, botanical fruits used as vegetables, and seedless culinary vegetables. Both highlight evidence that sweetness reliably predicts preferences in each food group and in both cultures, while ED might only predict preferences for seedless vegetables. Building on the above, Chapters 6 - 8 report studies exploring the relative role of ED and sweetness across vegans, vegetarians, and omnivores (Chapter 6), and age groups (Chapter 7) and sweet-liking phenotypes (Chapter 8). Together, this thesis exposes differences in preferences for certain types of fruit and vegetables at population (cultural), group (age group), and individual (sweet-liking phenotype) levels. This might be applicable to guide the selection of specific fruit and vegetables in any interventions aimed at increasing food consumption of this kind, ultimately effectively improving public health
The role of energy density and sweetness in predicting food preference, with a focus on fruit and vegetables
Zhai, Y. (Author). 20 Jan 2026
Student thesis: Doctoral Thesis › Doctor of Philosophy (PhD)