This secondary analysis of data from the Welsh Health Survey identified several risk factors associated with childhood obesity in Wales. Children who were female, older, from more deprived areas or routine/manual households, with treated illnesses, or not meeting physical activity recommendations had significantly higher odds of obesity. The findings suggest recommendations to increase physical activity in schools and support children with long-term conditions could help address modifiable risk factors.

1. Insert name of presentation on Master
Slide
A Secondary Analysis of the Cross-Sectional
Data Available in the ‘Welsh Health Survey for
Children’ to Identify Risk Factors Associated
with Childhood Obesity in Wales.
Presented by :Claire Beynon
Supervisor :Professor David Fone, Cardiff University

2. Claire Beynon
Why is childhood obesity a
problem?
• Prevalence of childhood obesity in Wales 12%.
• Impacts on both quality and quantity of life.
• Immediate effects:
low self esteem; bullying; depression; type II
diabetes.
• Long term effects:
Premature mortality; adult morbidity.
• Obesity costs £73 million per annum in Wales.

3. Claire Beynon
Why is childhood obesity a
problem?
Lobstein and
Jackson
Leach in
Foresight
Report, UK
Government
Office for
Science,
2007.

4. Claire Beynon
Research Question
• What are the important risk factors for childhood
obesity for children aged 4 to 15 years in Wales?
Research Objectives
• Identify and quantify cross-sectional associations
between obesity in children in Wales aged 4-15 years
and the risk factors available in the Welsh Health
Survey.
• Make recommendations for policy where appropriate.

5. Claire Beynon
Study Design
• Secondary Analysis of Data from the WHS.
• Dataset included n=11,279 children (aged 4-15 years)
between 2008 and 2011.
• Descriptive statistics, and logistic regression.

6. Claire Beynon
Risk Factors
• Socio-demographic/socioeconomic variables:
Sex, age, National Statistics Social Classification
(NSSEC), housing tenure and Welsh Index of Multiple
Deprivation (WIMD).
• Lifestyle variables:
Unhealthy food consumption; sugar sweetened
beverages; physical activity (PA) levels
• Illness:
Currently treated illnesses.

7. Claire Beynon
Results
Risk Factor Odds Ratio 95% CI P value
Sex Male Reference
Female 0.79 0.70 to 0.89 p<0.001*
Age 4-6 Reference
7-9 1.42 1.19 to 1.70 p<0.001*
10-12 1.65 1.39 to 1.97 p<0.001*
13-15 1.44 1.20 to 1.73 p<0.001*
Significant association between childhood obesity and the
following factors denoted with *

8. Claire Beynon
Results
Risk Factor OR 95% CI P value
NSSEC 3 Professional/ Managerial Reference
Intermediate 1.17 0.98 to 1.38 0.08
Routine/ Manual 1.32 1.14 to 1.54 p<0.001*
WIMD Lowest Reference
Low 1.08 1.19 to 1.70 p=0.44
Mid 1.23 1.01 to 1.50 p=0.04*
High 1.33 1.09 to 1.62 p=0.005*
Highest 1.23 0.99 to 1.53 p=0.06

9. Claire Beynon
Results
Risk Factor OR 95% CI P value
Illness No illness Reference
One illness 1.20 1.05 to 1.38 0.008*
Two or more illnesses 1.50 1.22 to 1.85 p<0.001*
Physical
Activity
Meets recommendation Reference
Does not meet
recommendation
1.33 1.17 to 1.52 p<0.001*

10. Claire Beynon
Results
Risk Factor OR 95% CI P value
Fruit & Veg Not daily Reference
Both daily 0.96 0. 85 to 1.09 p=0.82
SSB Not daily Reference
Daily 1.02 0.83 to 1.27 p=0.82
Junk food Not daily Reference
Daily 0.89 0.79 to 1.01 p=0.08
No significant association between childhood obesity and
the following factors:

11. Claire Beynon
Strengths of the study
• WHS uses stratified random sampling.
• Results for 3000 children achieved per annum.
• Good response rate at 75%.
• Known confounding accounted for by use of multivariable
analysis.
• Provides new insights into existing data.
• Information from Wales on which to base Welsh policy.

12. Claire Beynon
Limitations of the study
• Risk of bias, e.g. recall bias; reporting of food
consumption and physical activity reporting. Non
response bias.
• Reverse causality possible due to study design.
• Selection bias, private homes surveyed (not
institutions).
• Unknown confounding possible (not all risk factors
measured).
• Interactions not explored.

13. Claire Beynon
Conclusions
• Some risk factors associated with childhood obesity
are not modifiable (e.g. sex and age of the child).
• Some risk factors are not easily modifiable in the short
term, e.g. the circumstances of the family (NS-SEC
classification of the parent and housing tenure).
• Two findings are potentially more easily modifiable:
– the association between childhood obesity
and not meeting the PA recommendations
– the NHS response to the care planning of
children with a long term condition.

14. Claire Beynon
Recommendations
• Increase physical activity in schools to an hour a day,
so all children have levels of PA that protect them
from obesity without increasing inequalities in health.
• Extend the number and type of physical activity
options available to children across Wales both in
schools and out of school.
• Utilise the CMP feedback to provide advice on relevant
physical activity options that are affordable and
accessible e.g. green spaces; walks; free swimming.
• Ensure all children with a long term condition get help
to avoid or manage obesity through an holistic care
package.

15. Claire Beynon
Current Recommendations
• Physical activity

16. Claire Beynon
Results
Significant association between childhood obesity
and the following factors:
• being female OR 0.79 (95% CI: 0.70 to 0.89,
p<0.001);
• older age categories than the reference group (4-6
years) with ORs varying between 1.42 and 1.65 (all
significant at p<0.001);
• parents being in the routine, manual, never worked or
long term unemployed group OR 1.32 (95% CI: 1.14
to 1.54, p<0.001);

17. Claire Beynon
Results
Significant association between childhood obesity
and the following factors:
• mid and high quintiles of the WIMD.
OR for mid 1.23 (95% CI: 1.01 to 1.50, p=0.04) and
for high deprivation OR 1.33 (95% CI: 1.09 to 1.63,
p=0.005);
• having one or two currently treated illnesses.
OR for one illness 1.20 (95%CI: 1.05 to 1.38,
p=0.008) and for two or more illnesses OR 1.50 (95%
CI: 1.22 to 1.85, p<0.001)
• not meeting the PA recommendations OR 1.33 (95%
CI: 1.17 to 1.52, p<0.001).