Association between distorted body image and changes in weight status among normal weight preadolescents in Japan: a population-based cohort study.

Takako Shirasawa,Rimei Nishimura,Akatsuki Kokaze,Hinako Nanri,Hirotaka Ochiai,Keiichiro Ikeda,Hiromi Hoshino

doi:10.1186/s13690-016-0151-y

Takako Shirasawa, Rimei Nishimura + Show 5 more

Open Access

https://doi.org/10.1186/s13690-016-0151-y

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Abstract

BackgroundDistorted body image may be important risk factors for being underweight and overweight. The objective of this study was to investigate the association between having a distorted body image and being overweight or underweight among normal weight preadolescents in a population-based cohort study in Japan for each sex.MethodsThe study participants were 1431 normal weight fourth-grade students (age range: 9–10 years) in Ina town, Japan from 2002 to 2007. The height and weight of each student were measured while they were in the fourth grade (at baseline) and seventh grade (3 years later). Childhood underweight and overweight were defined using the body mass index cut-off points proposed by the International Obesity Task Force. Information regarding the self-perceived weight status of each student at baseline was collected using a self-administered questionnaire. Children who were normal weight but perceived themselves as heavy or thin were regarded as having a distorted body images. A logistic regression model was used to calculate the odds ratios (ORs) and 95 % confidence interval (95 % CI) for being overweight or underweight 3 years later among those having a distorted body image at baseline.ResultsBoth boys and girls who perceived themselves to be heavy at baseline were at a statistically significantly greater risk of being overweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: adjusted OR: 4.66, 95 % CI: 1.01–21.48; girls: 3.88, 1.56–9.65). Both boys and girls who perceived oneself to be thin at baseline were at a statistically significantly greater risk of bring underweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: 5.51, 2.20–13.80; girls: 2.93, 1.40–6.11).ConclusionThe results of the present study suggest that having a distorted body image in preadolescence is associated with being overweight or underweight in adolescence, among boys and girls, separately. Therefore, education regarding self-perceived weight could be important to help prevent underweight and overweight/obesity among preadolescent boys and girls in Japan.

Highlights

Distorted body image may be important risk factors for being underweight and overweight
No statistically significant differences were found between boys and girls in height or weight, but body mass index (BMI) was higher in boys than in girls (P = 0.004)
Both boys and girls who perceived oneself to be heavy at baseline were at a statistically significantly greater risk of being overweight or obese 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline

Summary

Introduction

Distorted body image may be important risk factors for being underweight and overweight. The objective of this study was to investigate the association between having a distorted body image and being overweight or underweight among normal weight preadolescents in a population-based cohort study in Japan for each sex. Recent studies have reported that the prevalence of thinness among Japanese adolescents boys and girls have progressively increased from 2.8–4.7 and 2.0–5.7 % in 2003–2004, respectively, to 5.1–7.6 and 3.5–7.8 % in 2011–2012 [3, 4]. Perkins et al reported that among both male and female students in UK, overestimating and underestimating peer weight norms were associated with a greater risk for being overweight and underweight, respectively [8]. To the best of our knowledge, no longitudinal studies have examined the association between having a distorted body image in preadolescence boys and girls and the development of overweight or underweight. To help prevent the development of overweight or underweight, the effect of having a distorted body image among preadolescents on developing overweight or underweight later in life should be prospectively investigated for each sex

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