Author	A.M. Fildes
Author	J. Wardle
Author	L. Cooke
Author	C.H. van Jaarsveld
Abstract	Poor diet contributes to the global burden of disease and food preferences play an important role, especially for children. Children generally like sweet, energy-dense foods and often dislike vegetables. However, there are considerable individual differences in liking and explanations for this variation remain elusive. This thesis uses data from a UK cohort of twins to examine the aetiology and development of children's food preferences with the aim of informing effective dietary interventions. Study 1 explored the underlying structure of children's preferences and found that empirically-derived food groups reflected traditional food categories. In infancy and childhood, liking for foods in the energy-dense snack food group were high and liking for vegetables was low. Study 2 investigated family and child characteristics associated with children's food preferences and showed that maternal diet and children's appetitive traits, particularly food fussiness, were strongly related to preferences. Study 3 used a twin design to investigate genetic and environmental influences on food preferences. Genetic effects on liking were strongest for vegetables, fruit and protein, while shared environmental effects were more important in liking for dairy and snack foods. Study 4 revealed common genetic influences behind vegetable liking and food fussiness, which explained the majority of the covariation between them. Study 5 was an RCT of parent-delivered taste exposure to modify children's vegetable acceptance. Intake and liking of a vegetable increased significantly more in intervention participants than controls, although individual variation in intervention response remained. Finally, Study 6 investigated whether variation in intervention response was genetically determined, but found that individual differences were primarily environmentally determined. This thesis provides evidence that genetically-determined food preferences are present in early life, particularly for nutritious foods like fruits and vegetables. In addition, Study 5 suggests that these inherited patterns of preference may be effectively modified using targeted interventions in childhood.