Accelerated Weight Gain Subsequent to Postnatal Slow Weight Gain and Overweight Risk in Early Childhood: A Nested Case-Control Study

Abstract

Background: The effects of accelerated weight gain (AWG) immediately after a postnatal slow weight gain (PSWG) on the risk of later overweight is unknown. The objective of this study was to assess the relationship between AWG after PSWG and overweight risk at 3 years of age. Methods: This nested case-control study included 255 subjects born at term, appropriate for gestational age, and with normal birth weight but PSWG (< 0.67 SD score) until 3–4 months of age. Overweight cases at 3 years of age were defined according to International Obesity Task Force criteria. The association between AWG after PSWG and overweight status at age 3 years was analyzed by the Fisher’s exact, Breslow-Day, and Mantel-Haenszel tests. Results: Seven of the subjects that showed AWG after PSWG were deemed overweight at age 3. An AWG from 6–9 to 17–20 months after PSWG during the first 3–4 months of life had the most significant association with overweight status at 3 years of age (adjusted OR 10.06, 95% CI 1.74–58.01, p value: 0.0022). Conclusions: AWG immediately after PSWG, even occurring at only 1 of 3 interval from 3–4 to 6–9 months, from 6–9 to 17–20 months, and 17–20 months to 3 years after PSWG, leads to an overweight status at 3 years of age. Monitoring weight growth after PSWG may help identify AWG and later overweight risk.