Maternal and child health are intrinsically linked. With accumulating evidence over the past two decades supporting the developmental origins of health and diseases hypothesis, it is now widely recognised that nutrition in the first 1000 d sets the foundation for long-term health. Maternal diet before, during and after pregnancy can influence the developmental pathways of the fetus and lead to health consequences later in life. While maternal and infant mortality rates have declined significantly in the past two decades, the growing burden of obesity and chronic non-communicable diseases in women of reproductive age and children is on a rapid rise worldwide, in developed and developing countries. A key contributory factor is malnutrition, which is a consequence of consuming poor quality diets. Suboptimal macronutrient balance and micronutrient inadequacies can lead to undesirable maternal body composition and metabolism, in turn influencing the health of the mother and leading to longer-term metabolic and cognitive health consequences in the infant. The GUSTO (Growing Up in Singapore Towards healthy Outcomes) study, a mother–offspring multi-ethnic cohort study in Singapore, has contributed to this body of evidence over the past 10 years. This review will illustrate how nutritional epidemiological research through a birth cohort has illuminated the importance and urgency of maternal and child nutrition and health in a modern, industrialised setting. It underscores the importance of a number of critical nutrients during pregnancy, in combination with healthy dietary patterns and appropriate meal timing, for optimal maternal and child health.