Maria Makrides is an international leader in maternal–infant nutrition, with a focus on optimising the cognition, growth and immune development of children. She is especially recognised for her rigorous nutritional intervention studies during the first 1000 days of life—between conception and a child’s second birthday. Her multidisciplinary research group conducts large-scale randomised controlled trials to investigate the health effects of dietary fatty acids, iron, iodine and novel dietary ingredients. She has made major contributions to changes in the composition of infant formulae, on changing international food laws and on setting specific nutrient recommendations worldwide.