New findings challenge a 42-year-old theory about why children's body mass index (BMI) declines after infancy and then begins climbing steadily from about age 6. The pattern has long been described as the "adiposity rebound," based on the idea that body fat first decreases and then returns.
However, the new analysis suggests that the later increase in BMI is not caused by a rebound in fat. Instead, it may largely reflect the normal growth of muscle and other lean tissue.
The research, led by Professor Andrew Agbaje, a physician and associate professor of clinical epidemiology and child health at the University of Eastern Finland, Kuopio, Finland, was presented at this year's European Congress on Obesity in Istanbul, Turkey and published in The Journal of Nutrition.
Why the Adiposity Rebound Theory Matters
Questioning the existence of the "adiposity rebound" could have important consequences for childhood health care. Since the theory was introduced, some physicians, including pediatricians, have treated the pattern as a meaningful warning sign that might be prevented or modified through diet and lifestyle changes.
