BMI Fails to Reflect the Developmental Changes in Body Fatness between Boys and Girls during Adolescence

Body mass index (BMI) is thought to reflect excess adiposity in both youth and adults alike. However, the association between BMI and fatness varies, especially as children grow into adults. Thus, the present study sought to address this issue by characterizing how BMI reflects age and sex differences in body fatness in 7–16-year-old children. Methods: This cross-sectional study was conducted with 2150 children and adolescents, aged 7 to 16 years from the city of Santa Cruz do Sul, Brazil. BMI (kg/m2), and percentage body fat, using tricipital and subscapular folds, were assessed. For statistical analysis, ANOVA and ANCOVA were used. Results: When considered in isolation, there was no significant interaction in the age-by-sex differences in BMI (p = 0.69). However, when we controlled for percent body fatness, the analysis revealed considerable age-by-sex differences in BMI (p < 0.001). Conclusion: For the same body fat (%), there are no differences in BMI in children <10 years.

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Body fatness or anthropometry for assessment of unhealthy weight status? Comparison between methods in South African children and adolescents

Public Health Nutrition ◽

10.1017/s1368980012004338 ◽

2012 ◽

Vol 16 (11) ◽

pp. 2005-2013 ◽

Cited By ~ 7

Author(s):

Eva Craig ◽

John Reilly ◽

Ruth Bland

Keyword(s):

Body Composition ◽

Children And Adolescents ◽

Body Fat ◽

Weight Status ◽

Cross Sectional Study ◽

Overweight And Obesity ◽

Sectional Study ◽

Cross Sectional ◽

Body Fatness ◽

Unhealthy Weight

AbstractObjectiveA variety of methods are available for defining undernutrition (thinness/underweight/under-fat) and overnutrition (overweight/obesity/over-fat). The extent to which these definitions agree is unclear. The present cross-sectional study aimed to assess agreement between widely used methods of assessing nutritional status in children and adolescents, and to examine the benefit of body composition estimates.DesignThe main objective of the cross-sectional study was to assess underweight, overweight and obesity using four methods: (i) BMI-for-age using WHO (2007) reference data; (ii) BMI-for-age using Cole et al. and International Obesity Taskforce cut-offs; (iii) weight-for-age using the National Centre for Health Statistics/WHO growth reference 1977; and (iv) body fat percentage estimated by bio-impedance (body fat reference curves for children of McCarthy et al., 2006). Comparisons were made between methods using weighted kappa analyses.SettingRural South Africa.SubjectsIndividuals (n 1519) in three age groups (school grade 1, mean age 7 years; grade 5, mean age 11 years; grade 9, mean age 15 years).ResultsIn boys, prevalence of unhealthy weight status (both under- and overnutrition) was much higher at all ages with body fatness measures than with simple anthropometric proxies for body fatness; agreement between fatness and weight-based measures was fair or slight using Landis and Koch categories. In girls, prevalence of unhealthy weight status was also higher with body fatness than with proxies, although agreement between measures ranged from fair to substantial.ConclusionsMethods for defining under- and overnutrition should not be considered equivalent. Weight-based measures provide highly conservative estimates of unhealthy weight status, possibly more conservative in boys. Simple body composition measures may be more informative than anthropometry for nutritional surveillance of children and adolescents.

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Differences in the relationship between BMI and percentage body fat between Japanese and Australian-Caucasian young men

British Journal Of Nutrition ◽

10.1079/bjn20061745 ◽

2006 ◽

Vol 95 (5) ◽

pp. 1002-1007 ◽

Cited By ~ 33

Author(s):

Masaharu Kagawa ◽

Deborah Kerr ◽

Hayato Uchida ◽

Colin W Binns

Keyword(s):

Body Fat ◽

Ethnic Differences ◽

Cross Sectional Study ◽

Body Density ◽

Sectional Study ◽

Cross Sectional ◽

Japanese Men ◽

Percentage Body Fat ◽

Caucasian Men ◽

The Relationship

This cross-sectional study aimed to determine ethnic and environmental influences on the relationship between BMI and percentage body fat, using a sample of 144 Japanese and 140 Australian-Caucasian men living in Australia, and eighty-eight Japanese men living in Japan. Body composition was assessed by anthropometry using standard international methods (International Society for the Advancement of Kinanthropometry protocol). Body density was predicted using Durnin and Womersley's (1974) equation, and percentage body fat was calculated from Siri's (1961) equation.Significant (P<0·05) ethnic differences in stature, body mass and BMI were observed between Japanese and Australian men, but no ethnic differences were observed in their percentage body fat and height-corrected sum of skinfold thicknesses. No differences were found in the BMI–percentage body fat relationship between the Japanese subjects living in Australia and in Japan. Significant (P<0·05) ethnic differences in the BMI–percentage body fat relationship observed from a comparison between pooled Japanese men(aged 18–40 years, BMI range 16·6–32·8kg/m2) andAustralians (aged 18–39 years, BMI range 16·1–31·4kg/m2) suggest that Japanese men are likely to havea greater percentage body fat than Australian men at any given BMI value.From the analyses, the Japanese men were estimated to have an equivalent amount of body fat to the Australian men at BMI values that were about 1·5 units lower than those of the Australians (23·5kg/m2 and 28·2kg/m2, respectively).It was concluded that Japanese men have greater body fat deposition than Australian-Caucasians at the same BMI value. Japanese men may therefore require lower BMI cut-off points to identify obese individuals compared with Australian-Caucasian men.

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Percentage Body Fat is As a Good Indicator for Determining Adolescents Who Are Overweight or Obese: A Cross-Sectional Study in Vietnam

Osong Public Health and Research Perspectives ◽

10.24171/j.phrp.2019.10.2.10 ◽

2019 ◽

Vol 10 (2) ◽

pp. 108-114 ◽

Cited By ~ 3

Author(s):

Le Thu Trang ◽

Nguyen Nam Trung ◽

Dinh-Toi Chu ◽

Nguyen Thi Hong Hanh

Keyword(s):

Body Fat ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Percentage Body Fat

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Dietary source of saturated fat and percentage body fat of patients with type 2 diabetes mellitus: A cross-sectional study

Food Science & Nutrition ◽

10.1002/fsn3.853 ◽

2018 ◽

Vol 7 (1) ◽

pp. 195-204 ◽

Cited By ~ 1

Author(s):

Camila Kümmel Duarte ◽

Ana Luiza Teixeira dos Santos ◽

Claudia Kirst ◽

Graziela da S. Nunes ◽

Karine de Franceschi ◽

...

Keyword(s):

Diabetes Mellitus ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Body Fat ◽

Saturated Fat ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Percentage Body Fat

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Associations between exposure to perfluoroalkyl substances and body fat evaluated by DXA and MRI in 109 adolescent boys

Environmental Health ◽

10.1186/s12940-021-00758-3 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Mathilde Lolk Thomsen ◽

Louise Scheutz Henriksen ◽

Jeanette Tinggaard ◽

Flemming Nielsen ◽

Tina Kold Jensen ◽

...

Keyword(s):

Body Fat ◽

Study Design ◽

Sulfonic Acid ◽

Standard Deviation Score ◽

Cross Sectional Study ◽

Mass Spectrometry Data ◽

Perfluoroalkyl Substances ◽

Sectional Study ◽

Cross Sectional ◽

Total Body

Abstract Background Exposure to perfluoroalkyl substances (PFASs) has been associated with changes in body mass index and adiposity, but evidence is inconsistent as study design, population age, follow-up periods and exposure levels vary between studies. We investigated associations between PFAS exposure and body fat in a cross-sectional study of healthy boys. Methods In 109 boys (10–14 years old), magnetic resonance imaging and dual-energy X-ray absorptiometry were performed to evaluate abdominal, visceral fat, total body, android, gynoid, android/gynoid ratio, and total fat percentage standard deviation score. Serum was analysed for perfluorooctanoic acid, perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid, perfluorononanoic acid, and perfluorodecanoic acid using liquid chromatography and triple quadrupole mass spectrometry. Data were analysed by multivariate linear regression. Results Serum concentrations of PFASs were low. Generally, no clear associations between PFAS exposure and body fat measures were found; however, PFOS was negatively associated with abdominal fat (β = -0.18, P = 0.046), android fat (β = -0.34, P = 0.022), android/gynoid ratio (β = -0.21, P = 0.004), as well as total body fat (β = -0.21, P = 0.079) when adjusting for Tanner stage. Conclusions Overall, we found no consistent associations between PFAS exposure and body fat. This could be due to our cross-sectional study design. Furthermore, we assessed PFAS exposure in adolescence and not in utero, which is considered a more vulnerable time window of exposure.

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