Preconception and early pregnancy health and diet in parents-to-be, early growth and childhood obesity risk

This thesis explores how maternal and paternal lifestyle and nutrition during the first 1,000 days of life influence reproductive outcomes, early offspring development, and the risk of childhood obesity. According to the Developmental Origins of Health and Disease framework, this period represents a critical window during which early-life exposures may shape later health. Using data from the Generation R Study, Generation R Next Study and the EndObesity Consortium, parental body mass index, diet and lifestyle were studied from preconception onwards. Findings show that suboptimal maternal preconception body mass index was associated with altered embryonic and subsequent fetal growth. Parental dietary factors were also associated with reproductive and developmental outcomes: higher maternal omega-3 fatty acid intake was associated with improved fertility, while higher paternal ultra-processed food intake as well as a higher dietary glycemic index was associated with reduced fertility. Higher maternal ultra-processed food intake was associated with smaller embryonic growth and yolk sac volume. Associations with parental lifestyle and nutrition extended into childhood. A more favorable maternal fatty acid profile during pregnancy was associated with lower offspring adiposity, obesity risk and better metabolic health at school age. In addition, adverse family-based lifestyle patterns during preconception and pregnancy were associated with a higher risk of childhood overweight and obesity across childhood. Together, these findings highlight the first 1,000 days as an important window of opportunity for family-based obesity prevention, considering both maternal and paternal lifestyle and nutrition.