Childhood Obesity, Weight Loss and Long Term Development in Quality-of-Life: A Longitudinal Follow-Up Study.

Background To evaluate long-term effects of a multifactorial lifestyle intervention on measures of quality-of-life (QoL) in children with obesity. Methods One hundred and twenty children age 4-17 years with a BMI standard deviation score (BMI-SDS) >2 participated in a multifactorial lifestyle intervention. QoL and wellbeing were measured by a 6-item Visual Analogue Scale (VAS) throughout the intervention. Results Follow-up time was 26.4 months (13.9 SD). VAS scores decreased on bullying (0.6 vs. 0.0 median) and in motivation (10.0 vs. 9.6). QoL increased in children with a BMI-SDS reduction (0.65 (2.49 SD)) opposite children with no-change or increasing BMI-SDS who reported reduced QoL (-0.36 (1.55 SD) and -0.96 (2.27 SD)). Boys experienced reduced appetite (6.7 (2.3 SD) to 5.7 (2.6 SD)), bullying (median 0.4 vs. 0.0) and motivation (median 10.0 vs. 8.9), while girls experienced reduction in bullying (median 0.6 vs. 0.0) and an enhancement in Joy of Life compared to boys (0.73 (2.10 SD) vs. -0.04 (2.08 SD)). Conclusion Multifactorial lifestyle intervention for children with obesity induces long-term BMI-SDS reduction for the majority, and exerts signicant reduction in bullying and improves QoL if weight loss is obtained and maintained.


Background
Children with obesity have decreased quality-of-life (QoL) compared to lean peers, and comparable to QoL in children having cancer [1]. Low QoL is associated with a higher risk of discrimination and bullying, which may lead to low self-esteem and even overt depression [2].
The Visual Analogue Scale (VAS) is a simple instrument with good validity and reliability. The VAS instrument is applicable to children who have insu cient reading skills and is therefore also useful in younger children [3].
Effects of lifestyle intervention on QoL after weight loss are only reported in a limited number of studies and rarely with follow-up for more than 12 months. Recently, a 14 months multifactorial lifestyle intervention in children with obesity reported increased QoL, mood, and body satisfaction whereas appetite, bullying, and motivation were decreased. Interestingly, similar positive changes were observed in ve of the six VAS items in the 24.4% of children who increased their Body Mass Index-Standard Deviation Score (BMI-SDS) during the intervention [4]. The aim of our study was to evaluate long-term effects of a comparable multifactorial lifestyle intervention on measures of QoL in children with obesity.

De nition of overweight and obesity
Overweight and obesity in growing individuals are de ned by an abnormal BMI-SDS (or z-score) or a BMI above a de ned percentile. BMI-SDS was calculated using GrowthXP (PC Pal, Wissous, France).

Patient and public involvement:
All children in our outpatient clinic for childhood obesity, their parents or legal guardians were invited to participate and the treatment e ciency was depended on their motivation, however, no formal patient and public involvement was performed.

Subjects:
One hundred and ninety-nine children age 4 to 17 years with a BMI-SDS > 2 [5] participated in The Children's Obesity Clinic's Treatment (TCOCT) protocol from January 1st 2014 to December 31st 2017. One hundred and twenty children completed a least two VAS-questionnaires; one of these at baseline. At baseline, data on obesity and mental illness predisposition were recorded. For all children a parent or legal guardian provided a written informed consent. All children were invited for a last visit and a renewed VAS in December 2018, one year after the TCOCT-project ended. No control group was included. Even though this trial was not a randomized study, the CONSORT-concept was followed.
The TCOCT protocol TCOCT is a family-centered multifactorial lifestyle intervention developed for treatment of children with overweight and obesity.
The TCOCT protocol is described in detail elsewhere [4]. In brief, participants had one yearly visit at our outpatient clinic and 6-8 municipality-based visits in-between.
At each visit at the outpatient clinic, anthropometry was measured and a six items VAS was completed.
Results on anthropometry, body composition, and metabolic parameters have previously been reported [6].
VAS -Visual analogue scale VAS recordings were performed at all visits at the outpatient clinic and used to evaluate participant's wellbeing in six different areas: 1. Joy of living (JoL), 2. QoL, 3. Appetite, 4. Bullying, 5. Motivation for losing weight, and 6. Body perception (Bpc). The child was instructed rigorously by a healthcare professional in a uniform way to rate his/her current state of mind expressed by the different VAS items with a single cross on a 10 cm vertical blank line, unnumbered except 0 and 10.

Statistics
Data was collected and managed using REDCap electronic data capture tools at Aarhus University. Statistical analyses were performed in Stata 15 (StataCorp, College Station, Texas). ANOVA was used to analyse data if normal distributed. Non-normal distributed data were analysed by Wilcoxon rank-sum (2 groups) or Kruskal-Wallis (more than 2 groups) tests. P-value of < 0.05 was considered statistically signi cant.

Changes in VAS:
Time between the rst and last VAS measurement was 26.4 months (13.9 SD). On average 2.7 VAS measurements were completed for each participant.
As outlined in Table 2   The last category is sub grouped in weight loss (< -0.1 ∆BMI-SDS), weight stagnation (-0.1 to 0.1 ∆BMI-SDS) and weight gain (> 0.1 ∆BMI-SDS)Ұ. P-values refer to comparisons between the variables in each group (respectively gender and weight development). All data is reported as mean value with standard deviations (SD).
* P-values refer to comparison between the baseline VAS (table1) and the last VAS obtained (not shown). † The relative development for VAS (∆VAS) was calculated as the difference between baseline and at the latest obtained VAS.

Discussion:
The aim of the study was to evaluate different measures of QoL after a lifestyle intervention in children with obesity. With a mean follow-up of 26.4 months, the study is to our knowledge the longest follow-up on QoL after a weight loss intervention.
An overall reduction in bullying and motivation was observed. Boys experienced a reduction in appetite, bullying and motivation, while girls experienced reduced bullying and improved JoL.
Interestingly, QoL was signi cant improved for children who reduced BMI-SDS compared to children with no-change or increasing BMI-SDS after the intervention. Similar but non-signi cant trends were observed for JoL, bullying, and Bcp. The dose-dependent weight loss measured in BMI-SDS with concomitant changes in measures of QoL is to our knowledge not reported previously.
One of the strengths of our study is that all VAS scores were obtained in uniformed method with simple instruction from a small team of healthcare professionals who were speci cally trained in the method.
An obvious limitation to this study is the lack of a control group. In addition, the limited number of participants increased the risk of type-2-error, exempli ed by the borderline-signi cant results obtained.
The main purpose of the TCOCT-intervention is to reduce BMI-SDS, however, it was considered an equal success to improve QoL and thereby reduce bullying and the development of psychosocial complications later in life [1,2].
The TCOCT intervention is used in the treatment of children with obesity in Denmark and our results ad to previous ndings [4], by including long-term follow-up in children who were more obese and younger. Fonvig et al. reported bene cial changes in 5 out of 6 VAS-items for children with increasing BMI-SDS. In contrast, our study displayed children with increasing BMI-SDS to have impaired JoL, QoL, and Bcp. The discrepancies may be explained by the longer follow-up in perhaps a more real-life situation.

Conclusion:
Our multifactorial lifestyle intervention induced a long-term BMI-SDS reduction paralleled by dosedependent improvements in QoL if a reduction in BMI-SDS was obtained. Ethics approval and consent to participate:

Abbreviations
This study was designed and conducted as a municipality-based treatment for children with obesity. At the time, when the study was designed and initiated, Danish legislation did not require registration of such of projects. Even though this trial was not a randomized study, the CONSORT-concept was followed and all procedures performed involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration. At rst visit a written consent was obtained for each participant completed by a parent or a legal guardian.

Consent for publication:
Written information was handed out to the families and written consent was obtained for each participant completed by a parent or a legal guardian.
Availability of data and material: Data will be shared on reasonable request.