The change in body weight from infancy to adulthood may impact later cardiometabolic health. In particular, early onset of excess weight gain and long duration of obesity in youth have been associated with an increased risk of cardiometabolic comorbidities in adulthood. High and low birth weight for gestational age, indicating abnormal fetal intrauterine growth, are also associated with an increased risk of cardiometabolic comorbidities in adulthood. There may be an interaction between birth weight and the change in body weight from infancy to adulthood, where the influence of weight gain on cardiometabolic health may depend on birth weight. In the present study, we aim to uncover the independent and combined effects of birth weight and the change in body weight from infancy to early adulthood, on cardiometabolic health in adulthood.