Multimodal Body Representation of Obese Children and Adolescents before and after Weight-Loss Treatment in Comparison to Normal-Weight Children

Abstract

Objective: The aim of the study was to investigate whether obese children and adolescents have a disturbed body representation as compared to normal-weight participants matched for age and gender and whether their body representation changes in the course of an inpatient weight-reduction program.

Methods: Sixty obese (OBE) and 27 normal-weight (NW) children and adolescents (age: 9-17) were assessed for body representation using a multi-method approach. Therefore, we assessed body size estimation, tactile size estimation, heartbeat detection accuracy, and attitudes towards one's own body. OBE were examined upon admission and before discharge of an inpatient weight-reduction program. NW served as cross-sectional control group.

Results: Body size estimation and heartbeat detection accuracy were similar in OBE and NW. OBE overestimated sizes in tactile size estimation and were more dissatisfied with their body as compared to NW. In OBE but not in NW, several measures of body size estimation correlated with negative body evaluation. After weight-loss treatment, OBE had improved in heartbeat detection accuracy and were less dissatisfied with their body. None of the assessed variables predicted weight-loss success.

Conclusions: Although OBE children and adolescents generally perceived their body size and internal status of the body accurately, weight reduction improved their heartbeat detection accuracy and body dissatisfaction.

Fig 1. Perception Scores of body perception in obese children (OBE) before weight loss (T1) in comparison to normal-weight children (NW).

The perception scores of everyday objects, body width, body depth, body circumference, tactile size estimation and heartbeat detection are displayed as box-whiskers with a cross, the latter depicting the mean. Except for the heartbeat detection score, values below 100 indicate an underestimation and values above 100 indicate an overestimation in terms of percent of the actual size. For the heartbeat detection, a score of 1 indicates absolute accuracy of heartbeat detection and the minimum score of 0 indicates that no heartbeat was perceived. The mean±standard deviation of the perception scores were as follows: Everyday objects–OBE: 103±08, NW: 103±07; Body width–OBE: 120±15, NW: 121±17; Body depth–OBE 115±20, NW: 115±17; Body circumference–OBE: 85±16, NW: 89±16; Tactile size estimation–OBE: 182±41, NW: 152±25; Heartbeat detection–OBE: 0.47±0.26, NW: 0.52±0.20. Due to multiple testing the p-values were false discovery rate (FDR)-adjusted. FDR values <0.05 were considered as statistically significant. ** indicates FDR<0.01.

Fig 2. Perception Scores of body perception in obese children (OBE) before (T1) and after weight loss (T2).

A: The perception scores of everyday objects, body width, body depth, body circumference, tactile size estimation and heartbeat detection are displayed as box-whiskers with a cross, the latter depicting the mean. Except for the heartbeat detection score, values below 100 indicate an underestimation and values above 100 indicate an overestimation in terms of percent of the actual size. For the heartbeat detection, a score of 1 indicates absolute accuracy of heartbeat detection and the minimum score of 0 indicates that no heartbeat was perceived. The mean±standard deviation of the perception scores were as follows: Everyday objects–T1: 103±08, T2: 105±08; Body width–T1: 120±15, T2: 120±14; Body depth–T1: 115±20, T2: 119±16; Body circumference–T1: 85±16, T2: 85±12; Tactile size estimation–T1: 182±41, T2: 183±35; Heartbeat detection–T1: 0.47±0.26, T2: 0.63±0.21. Due to multiple testing the p-values were false discovery rate (FDR)-adjusted. FDR values <0.05 were considered as statistically significant. *** indicates FDR<0.001. B: The change values of the perception scores in OBE are presented as box-whiskers.