Abstract
Context. The overweight – as distinct from obese – child is a potential target for obesity prevention interventions, on the assumption that overweight often progresses to obesity. However, there is limited empirical evidence on the probability that overweight progresses to obesity in contemporary children. Aim. To quantify progression from overweight to obesity in a large contemporary cohort of children. Methods. Changes in weight status were studied longitudinally in 7-year-olds (n=5 175) participating in the Avon Longitudinal Study of Parents and Children (ALSPAC), over a 6-year period. Obesity was defined as BMI z-score ≥1.64 and overweight defined as BMI z-score ≥1.04 but <1.64. Results. Adjusted odds ratio for progression to obesity at age 13 for overweight at age 7 was 18.1 (95% CI 12.8–25.6), and 34% of overweight children at age 7 became obese by age 13 years. Conclusions. The present study could inform judgements as to the value of monitoring changes in weight status in overweight children, and the extent to which the overweight state might be a useful target of future obesity prevention interventions.
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Acknowledgements
Author contributions.
Original concept: Reilly.
Design, Acquisition, and Interpretation of data: all authors.
Drafting and revision of manuscript for important intellectual content: all authors. Final approval of submission: all authors.
Guarantors: Reilly and Sherriff had access to all data and take responsibility for the integrity of the data and accuracy of data analysis.
Funding: The UK Medical Research Council, the Wellcome Trust, and the University of Bristol provide core support for ALSPAC.
Role of the funder: The funding body had no role in the content of the present paper or the decision to publish.
Other contributors: We are extremely grateful to all the families who took part in this study, the midwives for their help in recruiting them, and the whole ALSPAC Team which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists and nurses.
Ethics Committee approval: ALSPAC Law and Ethics Committee plus three NHS local research ethics committees.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.