# Association between size at birth, rapid weight gain in infancy, and overweight status among Palestinian refugees under 5 years old: a retrospective cohort study

## TL;DR

The study finds that rapid weight gain in infancy is strongly linked to childhood overweight/obesity among Palestinian refugee children, regardless of birth size.

## Contribution

The study provides novel insights into the relationship between birth size, rapid weight gain, and childhood obesity in a refugee population.

## Key findings

- Small for gestational age children had higher odds of rapid weight gain but lower odds of later overweight/obesity.
- Large for gestational age children had lower odds of rapid weight gain but higher odds of later overweight/obesity.
- Exclusive human milk feeding was associated with reduced risk of rapid weight gain and subsequent overweight/obesity.

## Abstract

Evidence on the association of birth size and rapid weight gain with overweight/obesity is inconsistent. Refugees face unique nutritional challenges that influence weight patterns, yet data remain limited.

We examined the association between size at birth, infant feeding, and rapid weight gain in the first year of life, and subsequent overweight/obesity in childhood among Palestinian refugees.

This retrospective cohort study used data from 388,347 live births from 1 January, 2010 to 31 December, 2020, linked to child growth monitoring data using United Nations Relief and Works Agency electronic-health records. The cohort included children aged 0 to 60 mo from 5 regions: Gaza, Jordan, Lebanon, Syria, and the West Bank. Size at birth was categorized into 9 phenotypes, and rapid weight gain was defined as an increase of 0.67 in weight-for-age z-score from birth until age 12 mo. Overweight/obesity occurrence was defined as a weight-for-height z-score >+2 at any time point after 24 to 60 mo of age. Multilevel mixed-effects models and structural equation modeling were used to analyze associations.

Small for gestational age children had lower odds of exclusive human milk feeding [adjusted odds ratio (aOR): 0.83; 95% confidence interval (CI): 0.81, 0.85], higher odds of rapid weight gain (aOR: 2.39; 95% CI: 2.32, 2.45), and lower odds of overweight/obesity (aOR: 0.50; 95% CI: 0.46, 0.56) compared with appropriate for gestational age children. Large for gestational age children showed lower odds of rapid weight gain (aOR: 0.35; 95% CI: 0.33, 0.36) but higher odds of overweight/obesity (aOR: 2.76; 95% CI: 2.59, 2.95) compared with appropriate for gestational age. Between 22.2% and 34.4% of children experienced rapid weight gain. Rapid weight gain was strongly associated with overweight/obesity at 24 to 60 mo (aOR: 6.53; 95% CI: 6.15, 6.94). Exclusive human milk feeding was associated with lower odds of rapid weight gain (aOR: 0.66; 95% CI: 0.65, 0.67).

Rapid weight gain in infancy, regardless of birth size, is a predictor of childhood overweight/obesity. Exclusive human milk feeding mitigates the risk of rapid weight gain and subsequent overweight/obesity.