Hormonal regulatory mechanisms in obese children and adolescents after previous weight reduction with a lifestyle intervention: maintain - paediatric part - a RCT from 2009-15.

BACKGROUND: Weight loss improves cardiovascular risk factors and "quality of life". Most therapeutic approaches fail to induce a sustained weight loss and most individuals undergo weight regain. In this paper the comprehensive design of the "MAINTAIN" study, all assessments as well as the one year lifestyle intervention will be outlined in detail.

METHODS/DESIGN: One-center randomized controlled trial with seven assessment time points conducted 2009-2015. For the randomization eight groups were distinguished in a list to allocate intervention or control group: Females and males either pre-pubertal or pubertal and with a BMI-SDS under or over 2.5.

SETTING: Weight loss at a residential weight reduction programme Berlin/Brandenburg and intervention at a paediatric outpatient clinic;

PARTICIPANTS: 137 children and adolescents (10 to 17 years).

INTERVENTION: PARTICIPANTS were randomized after an initial weight loss at a residential weight reduction programme and allocated to intervention (n=65) and control (n=72) conditions. The intervention group received an one-year group multi-professional lifestyle intervention with monthly meetings at the paediatric outpatient obesity clinic. The control group had a free living phase for one year and both groups 48 months follow up.

MAIN OUTCOME MEASURES: PARTICIPANTS who are engaged in monthly intervention meetings will benefit in terms of a sustained weight maintenance. The primary aim is to describe the dynamic of hormonal and metabolic mechanisms counter-balancing sustained weight loss during puberty and adolescence. The secondary aim is to investigate the effect of an intensive family based lifestyle intervention during the weight maintenance period on the endogenous counter-regulation as well as on health related quality of life. The third aim is to establish predictors for successful weight maintenance and risk factors for weight regain in obese children and adolescents.

DISCUSSION: Weight maintenance after induced weight loss is one of the most important therapeutic challenges as long as most patients fail to maintain their weight loss. MAINTAIN is the first paediatric RCT addressing in parallel to a RCT in obese adults the course of weight regain after induced weight loss and is embedded in an experimental research consortium in order to also address several molecular mechanisms of weight regain.

TRIAL REGISTRATION: ClinicalTrials NCT00850629, first registration 17 February 2009, verified January 2012, Paediatric part of the interventional study. Ethic proposal approved at 08.04.2009.