Early determinants of obesity.

High rates of overweight and obesity even in very young children argue the case for strategies to prevent overweight from very young ages. Historical studies, prospective birth cohorts, and more recently genetic studies all indicate that the rapid weight gain trajectory to later obesity starts in the first months of life, even from birth. Early puberty and age at menarche are consequences of rapid infant weight gain and childhood overweight, and in turn these adolescent traits are predictive for obesity, diabetes, hypertension and cardiovascular disease events in later life. Understanding of the nutritional, parental and wider determinants of rapid infant weight gain are informing the development of obesity prevention strategies starting in early life. Such strategies could be further refined by future studies that address the specific regulation of infant adiposity, and also by studies that explore whether these life-course trajectories are modifiable during adolescence.