Childhood obesity: what is the minimum change in BMI-SDS needed to reduce body fat?

Childhood obesity interventions that lead to children’s body mass index standard deviation scores (BMI-SDS) being reduced by at least 0.6 may be deemed successful in reducing body fat mass, NIHR Bristol Biomedical Research Centre researchers have found in a review published in BMJ Open.

BMI values, which are used to classify whether an adult is overweight or obese, don’t work for children because they are still growing. BMI-SDS is a way of using population data to standardise BMI for children and adolescents. The review looked at the existing evidence to establish the minimum change in BMI-SDS needed to reduce body fat in children and adolescents with obesity. The researchers found 39 studies to analyse as part of the review.

Research has shown that lifestyle interventions may lead to improvements in weight and other outcomes for children with obesity. However, whilst many childhood obesity intervention programmes describe statistically significant reductions in BMI-SDS, these results are not of the magnitude to necessarily translate into benefit for the individual. By pinpointing the threshold at which a change in BMI-SDS results in reduction of body fat, the researchers hope to be able to inform clinical guidelines for childhood weight management interventions and to guide outcome measures in future trials.

Read the paper

What change in body mass index is associated with improvement in percentage body fat in childhood obesity? A meta-regression
Laura Birch, Rachel Perry, Linda P Hunt, Rhys Matson, Amanda Chong, Rhona Beynon, Julian PH Shield.

Published in BMJ Open