Weight Gain in the First Week of Life and Overweight in Adults

Early nutrition appears to have a programming effect on health later in life. Recent
studies suggest that very rapid weight gains during infancy are associated with becoming
overweight in childhood. Since public health efforts are focusing on early prevention of
obesity, identifying critical periods can point the way to more effective interventions. The
purpose of this study was to examine the relationship of rapid infant weight gain to the
risk of becoming overweight in adulthood.

The authors used data from the Iowa infant growth study and a follow-up interview more
than 20 years later to determine the relationship of early growth patterns to adult
overweight status. Compiled from 1965-1978, the original dataset included 952 healthy,
white, formula-fed infants whose growth was measured from birth to 112 days of life.
The authors did a nationwide search to locate these individuals during young adulthood.
They were able to find and interview by phone72% (n=653) of those eligible for the
follow-up study. A primary outcome was adult body mass index (BMI), based on self-
reported weights and heights.

The median age of the subjects at follow-up was 23 years. While only 5.7% were obese,
about 32% were overweight (BMI>25 kg/m2). Absolute weight gain in the first eight
days of life was significantly associated with being overweight as a young adult. A 100
gm increase in infant weight gain during the first week of life was associated with 28%
greater risk of becoming overweight, even after accounting for the positive effects of
birth weight, parents’ BMI, age, and income. Other factors associated with increased risk
were use of soy formula (reason unknown), greater mother’s weight (but not father’s
weight), and higher birth weight.

Conclusions and Implications: In formula-fed infants, a rapid weight gain in the first
week of life is associated with overweight in adulthood. Based on this observational
study, one cannot infer a cause and effect relationship because underlying genetic or
other factors could cause for both the early infant weight gain pattern and overweight
status in adulthood. These findings also do not necessarily apply to nonwhite,
racially/ethnically diverse populations.

Source: Stettler N, Stallings VA, Troxel AB, Zhao J, Schinnar R, Nelson SE, Ziegler EE, Strom BL. Weight
gain in the first week of life and overweight in adults. A cohort study of European American subjects fed infant
formula. Circulation 2005; 111:1897-1903