What change in body mass index is associated with improvement in percentage body fat in childhood obesity? A meta-regression. Issue 8 (30th August 2019)

• Record Type: Journal Article
• Authors: Birch, Laura; Perry, Rachel; Hunt, Linda P; Matson, Rhys; Chong, Amanda; Beynon, Rhona; Shield, Julian PH
• Is Part Of: BMJ open. Volume 9:Issue 8(2019)
• Publication Date: 2019-08-30
• Subjects: obesity -- childhood -- adolescence -- body mass index -- body fat; Medicine -- Research -- Periodicals; 610.72
• DOI: 10.1136/bmjopen-2018-028231
• Languages: English
• ISSNs: 2044-6055

Abstract

Abstract : Objective: Using meta-regression this paper sets out the minimum change in body mass index-SD score (BMI-SDS) required to improve adiposity as percentage body fat for children and adolescents with obesity. Design: Meta-regression. Setting: Studies were identified as part of a large-scale systematic review of the following electronic databases: AMED, Embase, MEDLINE via OVID, Web of Science and CENTRAL via Cochrane library. Participants: Individuals aged 4–19 years with a diagnosis of obesity according to defined BMI thresholds. Interventions: Studies of lifestyle treatment interventions that included dietary, physical activity and/or behavioural components with the objective of reducing obesity were included. Interventions of <2 weeks duration and those that involved surgical and/or pharmacological components (eg, bariatric surgery, drug therapy) were excluded. Primary and secondary outcome measures: To be included in the review, studies had to report baseline and post-intervention BMI-SDS or change measurements (primary outcome measures) plus one or more of the following markers of metabolic health (secondary outcome measures): adiposity measures other than BMI; blood pressure; glucose; inflammation; insulin sensitivity/resistance; lipid profile; liver function. This paper focuses on adiposity measures only. Further papers in this series will report on other outcome measures. Results: This paper explores the potential impact of BMI-SDS reduction in terms of change in percentage body fat. Thirty-nine studies reporting change in mean percentage body fat were analysed. Meta-regression demonstrated that reduction of at least 0.6 in mean BMI-SDS ensured a mean reduction of percentage body fat mass, in the sense that the associated 95% prediction interval for change in mean percentage body fat was wholly negative. Conclusions: Interventions demonstrating reductions of 0.6 BMI-SDS might be termed successful in reducing adiposity, a key purpose of weight management interventions. Trial registration number: CRD42016025317.