.
Dynamic changes in body weight have long been recognized as important indicators of risk
for human health. Many population-based observational studies have shown that rapid weight
gain during infancy, including a catch-up growth phenomenon or adiposity rebound in early
childhood, predisposes a person to the development of obesity, type 2 diabetes, and
cardiovascular diseases later in life. However, a consensus has not been established
regarding which period of weight gain contributes to future risks. This review evaluates
recent evidence on the relationship between early rapid growth and future obesity and
cardiometabolic risk, with a focus on the differential significance of rapid weight gain
in infancy and early childhood. Although there is a need for attention to childhood growth
during early infancy before 1 yr of age as it may be related to future obesity, emerging
evidence strongly suggests that toddlers showing an increase in body mass index (BMI)
before 3 yr of age, a period normally characterized by decreased BMI, are prone to
developing later cardiometabolic risk.