Influence of nutrition in infancy on appetite characteristics, dietary intake, growth and later obesity risk

Childhood obesity is a global epidemic and public health challenge. One of the factors shown to influence later obesity is early nutrition, through a process known as programming. However, the mechanism by which early life factors affect later risk of obesity are unknown. This PhD aimed to investigate 1) the influence of early nutrition and growth on pre-school (2-5 years) obesity risk (Study 1); 2) the impact of early life factors on appetite development (Study 2) and 3) the influence of early nutrition on later diet (dietary patterns and energy & macronutrient intake) (Study 3). Data from the Optigrow infant feeding study was used to explore associations between early life factors and later obesity risk and understand the potential underlying mechanisms. Study 1 demonstrated that faster growth in infancy was associated with greater risk of obesity at pre-school age. There was no association between infant feeding and obesity risk. In Study 2, cross-sectional analyses showed that high satiety responsiveness was associated with lower risk of obesity at pre-school age. In the longitudinal analyses, high food responsiveness at 4 months increased risk of obesity at age 1 and 2. Food approach traits tracked poorly from infancy to pre-school age. Food avoidant traits did not track beyond 1 year of age. Faster infant weight gain during the first 6 months of life was associated with poor satiety responsiveness at pre-school age. Study 3 identified three dietary patterns namely: ‘health conscious’, ‘energy-dense, high meat, high-fat’ and ‘snack’ at pre-school age. ‘Energy-dense, high meat, high-fat’ pattern was associated with BMI z-score at pre-school age. There was no association between infant feeding (formula- and breast-fed) and dietary intake (energy and macronutrient intake) at pre-school age. The above findings suggests that satiety responsiveness may be an important factor linking infant growth with later obesity risk