Background

The best outcomes for treating childhood obesity have come from comprehensive family-based programmes. However there are questions over their generalisability.

Objective

To examine the acceptability and effectiveness of ‘family-based behavioural treatment’ (FBBT) for childhood obesity in an ethnically and socially diverse sample of families in a UK National Health Service (NHS) setting.

Methods

In this parallel group, randomised controlled trial, 72 obese children were randomised to FBBT or waiting list control. Primary outcomes were body mass index (BMI) and BMI standard deviation scores (SDS). Secondary outcomes were weight, weight SDS, height, height SDS, waist, waist SDS, fat mass index, fat free mass index, blood pressure, and psychosocial measures. Outcomes were assessed at baseline and post-treatment, with analyses on the 6 month data done on an intent-to-treat (ITT) basis. Follow-up anthropometric data were collected at twelve months for the treatment group.

Results

ITT analyses included all children with baseline data (n=60). There were significant BMI SDS changes (p<0.01) for the treatment and control groups of −0.11 (0.16) and −0.10 (1.6). The treatment group showed a significant reduction in systolic blood pressure (−0.24 (0.7), p<0.05) and improvements in quality of life and eating attitudes (p<0.05), with no significant changes for the control group. However the between-group treatment effects for BMI, body composition, blood pressure and psychosocial outcomes were not significant. There was no overall change in BMI or BMI SDS from 0-12 months for the treatment group. No adverse effects were reported.

Conclusions

Both treatment and control groups experienced significant reductions in level of overweight, but with no significant difference between them. There were no significant group differences for any of the secondary outcomes.

Objective To determine cut offs to define thinness in children and adolescents, based on body mass index at age 18 years.

Design International survey of six large nationally representative cross sectional studies on growth.

Setting Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States.

Subjects 97 876 males and 94 851 females from birth to 25 years.

Main outcome measure Body mass index (BMI, weight/height2).

Results The World Health Organization defines grade 2 thinness in adults as BMI <17. This same cut off, applied to the six datasets at age 18 years, gave mean BMI close to a z score of −2 and 80% of the median. Thus it matches existing criteria for wasting in children based on weight for height. For each dataset, centile curves were drawn to pass through the cut off of BMI 17 at 18 years. The resulting curves were averaged to provide age and sex specific cut-off points from 2-18 years. Similar cut offs were derived based on BMI 16 and 18.5 at 18 years, together providing definitions of thinness grades 1, 2, and 3 in children and adolescents consistent with the WHO adult definitions.

Conclusions The proposed cut-off points should help to provide internationally comparable prevalence rates of thinness in children and adolescents.