Does body weight affect child development?

One-fifth of preschool age children in high income countries are overweight or obese . Although studies have linked being overweight or obese with poorer outcomes in later childhood and adulthood, very little research has looked at these associations with development in young children.

Researchers at the University of Adelaide, led by Anna Pearce, examined the AEDC outcomes of kindergarten children who were thin, healthy-weight, overweight, or obese.

BMI was used to categorized children as thin, healthy, overweight, or obese based on the International Obesity Task Force age- and sex-specific cut-offs.


Total = 7,553

Thin (416) 6%
Healthy-weight (5,659) 75%
Overweight (1,100) 15%
Obese (358) 5%

What did they find?

Physical health & well-being Social competence Emotional maturity Language & cognitive skills Communication & general knowledge Vulnerable on one or more domains
Thin 8.7% 8.4% 9.4% 4.1% 6.7% 19.7%
Healthy-weight 7.6% 7.9% 8.9% 4.1% 5.6% 18.5%
Overweight 6.8% 7.0% 7.3% 3.0% 5.5% 16.1%
Obese 18.7% 11.2% 10.3% 5.3% 7.5% 29.6%

Outcomes for thin children were similar to those of healthy-weight children across all domains. In comparison, overweight children had slightly lower risks for developmental vulnerability than their thin and healthy-weight peers. However, the differences were not overly large, especially after controlling for confounding factors. Obese children were more likely to be vulnerable than healthy-weight children. In fact, even after controlling for confounding variables, obese children were twice as likely as healthy-weight children to be developmentally vulnerable on the physical health and well-being domain.

What does it mean?

A wealth of literature shows reducing obesity benefits physical health conditions and life expectancy in adulthood. The findings from this study imply that tackling early childhood obesity may also have positive impacts for child development, leading to improvements in academic achievement.