& 2011 Macmillan Publishers Limited All rights reserved 0307-0565/11 www.nature.com/ijo PEDIATRIC ORIGINAL ARTICLE
Fast food, other food choices and body mass index in teenagers in the United Kingdom (ALSPAC): a structural equation modelling approach
LK Fraser1, KL Edwards2, JE Cade3 and GP Clarke1
1
School of Geography, University of Leeds, Leeds, UK; 2Division of Biostatistics, University of Leeds, Leeds, UK and 3Nutritional Epidemiology Group, University of Leeds, Leeds, UK
Objective: To assess the association between the consumption of fast food (FF) and body mass index (BMI) of teenagers in a large UK birth cohort.
Methods: A structural equation modelling (SEM) approach was chosen to allow direct statistical testing of a theoretical model.
SEM is a combination of confirmatory factor and path analysis, which allows for the inclusion of latent (unmeasured) variables.
This approach was used to build two models: the effect of FF outlet visits and food choices and the effect of FF exposure on consumption and BMI.
Results: A total of 3620 participants had data for height and weight from the age 13 clinic and the frequency of FF outlet visits, and so were included in these analyses. This SEM model of food choices showed that increased frequency of eating at FF outlets is positively associated with higher consumption of unhealthy foods (b ¼ 0.29, Po0.001) and negatively associated with the consumption of healthy foods (b ¼ À1.02, Po0.001). The SEM model of FF exposure and BMI showed that higher exposure to
FF increases the frequency of visits to FF outlets (b ¼ 0.61, Po0.001), which is associated with higher body mass index standard deviation score (BMISDS; b ¼ 0.08, Po0.001). Deprivation was the largest contributing variable to the exposure (b ¼ 9.2,
Po0.001).
Conclusions: The teenagers who ate at FF restaurants consumed more unhealthy foods and were more likely to have higher
BMISDS
References: 1 Craig RS. Health survey for England 2007, 2008. Available from http://www.natcen.ac.uk/study/health-survey-for-england-2007. 2 Keynote. UK fast food and home delivery outlets, 2006. 27 Cole TJ, Freeman JV, Preece MA. Body-mass index reference curves for the UK, 1990 29 Index of Multiple Deprivation 2007 (IMD 2007). The Guildford Press: New York, 2005.