Rapid growth in infancy and childhood and obesity in later life--a systematic review.

The association between obesity and morbidity resulting from chronic diseases is well known. This systematic review addresses studies of the role of rapid growth in infancy and childhood as possible determinants of overweight and obesity later in the life course. We reviewed MEDLINE for studies reporting on growth in infancy and childhood, as well as measures of weight or adiposity in later childhood, adolescence or adulthood. The methodological quality of the papers was assessed using the criteria suggested by Downs and Black. Sixteen articles that fulfilled review criteria were located. There was wide variability in the indicators used for defining rapid growth as well as overweight or obesity. The age range in which weight or adiposity was measured ranged from 3 to 70 years. In spite of differences in definitions used, 13 articles that reported on early rapid growth found significant associations with later overweight or adiposity. Efforts should be made to standardize the definition of rapid growth, as well as that of overweight and obesity in children and adolescents. The most frequent definition for rapid growth in this review was a Z-score change greater than 0.67 in weight for age between two different ages in childhood. Regarding obesity, the definition proposed by the International Obesity Task Force also appears to be most appropriate. The present results indicate that early growth is indeed associated with the prevalence of obesity later in the life course.