# Association between obesity and mental health problems among Spanish children aged 9 and 12 years: the ELOIN study

## TL;DR

This study finds that obesity in Spanish children aged 9 and 12 is linked to higher mental health difficulties, including emotional and behavioral issues.

## Contribution

The study provides new evidence on the association between childhood obesity and mental health risks in a longitudinal Spanish cohort.

## Key findings

- Children with obesity had higher SDQ scores and increased mental health risk compared to non-obese peers.
- Obese children showed higher odds of emotional problems, conduct issues, and peer relationship difficulties.
- The association between obesity and mental health difficulties was stronger in girls, though not statistically significant.

## Abstract

Obesity is an important determinant of mental health in the child and adolescent population. In this study, the association between obesity and the development of psychological problems in Spanish children aged 9 and 12 years was examined.

In this prospective study, 2,473 9-year-old children and 2,119 12-year-olds who participated in the Longitudinal Study of Childhood Obesity (ELOIN) were evaluated. The standardized BMI was calculated from weight and height, and weight status was classified according to the 2007 World Health Organization criteria. Mental health difficulties were assessed using the Strengths and Difficulties Questionnaire (SDQ), which was completed by the parents. BMI and SDQ scores were determined repeatedly at 9 and 12 years of age. Using generalized estimating equations, β coefficients were calculated when analysing the SDQ scores, and odds ratios (ORs) were calculated to estimate mental health risk using Goodman´s British cut-off points.

Compared with participants without obesity, those who had obesity had a higher total score on the SDQ (β coefficient: 1.12 (95% CI: 0.59; 1.64)) and an increased risk of mental health risk (OR: 1.36 (95% CI: 1.09; 1.69)). ORs of 1.48 (95% CI: 1.21; 1.81) for emotional problems, 1.40 (95% CI: 1.15; 1.70) for conduct problems, and 2.25 (95% CI: 1.83; 2.77) for problems with peers were estimated. This association of weight status with mental health difficulties was moderately greater in girls than in boys, although the difference was not statistically significant.

Childhood obesity was associated with mental health difficulties, especially emotional symptoms, behavioural problems and relationships with peers. Identifying and responding to these psychological problems should also be an objective in public health policies and procedures for controlling obesity in children.

The online version contains supplementary material available at 10.1186/s12889-026-26349-w.