Long-term changes in body composition and prevalence of overweight and obesity in girls (aged 3–18 years) from Kraków (Poland) from 1983, 2000 and 2010

To examine the influence of age and gender on the waist:height ratio (WHTR) in children and to compare changes over time in WHTR, a measure of central fatness in British children. Representative cross-sectional surveys in 1977, 1987 and 1997. Great Britain and Northern Ireland. Survey 1: children aged 5-16 years measured in 1977 (boys) and 1987 (girls) (BSI, n=8135) and Survey 2: children aged 11-16 measured in 1997 (NDNS, n=773). From Survey 1, waist: height ratio related to age and sex and the proportion of children with a WHTR greater than 0.500 (a boundary value suggested for adults). From Survey 2, comparison of WHTR in children with that from Survey 1 and the actual proportion of children with a WHTR greater than 0.500 compared with the expected proportion using the survey 1 as reference. WHTR decreased with age (P<0.01 for trend), with the mean WHTR being significantly lower in girls (P<0.01). WHTR was significantly greater in children in Survey 2 compared with those measured 10 and 20 years earlier in Survey 1 (P<0.0001). The proportion of children where WHTR exceeded the 0.500 boundary value in Survey 2 was 17% of boys and 11.7% of girls (against 5.0 and 1.5%, respectively, in Survey 1, P<0.0001). The increase in WHTR in boys exceeded that in girls. Values of WHTR during the past 10-20 years have increased greatly showing that central fatness in children has risen dramatically. WHTR is more closely linked to childhood morbidity than body mass index (BMI) and we suggest it should be used as an additional or alternative measure to BMI in children as well as adults. A simple public health message that is the same for adults and children of both sexes and all ages could be stated as 'keep your waist circumference to less than half your height'.

Objective Previous data indicate a rapidly increasing prevalence of obesity and overweight among English children and an emerging socioeconomic gradient in prevalence. The main aim of this study was to update prevalence trends among school-age children and assess the changing socioeconomic gradient. Design A series of nationally representative household-based health surveys conducted between 1997 and 2007 in England. Subjects 15,271 white children (7880 boys) aged 5 to 10 years with measured height and weight. Measurements Height and weight were directly measured by trained fieldworkers. Overweight (including obesity) and obesity prevalence were calculated using the international body mass index cut-offs. Socioeconomic position (SEP) score was a composite score based on income and social class. Multiple linear regression assessed the prevalence odds with time point (1997/8, 2000/1, 2002/3, 2004/5, 2006/7) as the main exposure. Linear interaction terms of time by SEP were also tested for. Results There are signs that the overweight and obesity trend has levelled off from 2002/3 to 2006/7. The odds ratio (OR) for overweight in 2006/7 compared to 2002/3 was 0.99 (95% CI 0.88 to 1.11) and for obesity OR = 1.06 (0.86 to 1.29). The socioeconomic gradient has increased in recent years, particularly 2006/7. Compared to 1997/8, the 2006/7 age and sex-adjusted OR for overweight was 1.88 (1.52 to 2.33) in low SEP, 1.25 (1.04 to 1.50) in middle SEP, and 1.13 (0.86 to 1.48) in high SEP children. Conclusion Childhood obesity and overweight prevalence among school-age children in England has stabilised in recent years, but children from lower socio-economic strata have not benefited from this trend. There is an urgent need to reduce socio-economic disparities in childhood overweight and obesity.

Arm muscle area (AMA, cm2) is currently calculated from triceps skinfold thickness (TSF, cm), and midarm circumference (MAC, cm). In assessing the accuracy of the current equation by comparison to AMA measured by computerized axial tomography, error in each of the four approximations made was found to result in a 20 to 25% overestimate of AMA. Two correctible error sources were: a 10 to 15% overestimation caused by assuming a circular midarm muscle compartment and a 5 to 10% overestimation due to inclusion of midarm cross-sectional bone area. Corrected AMA equations for men and women were respectively: [(MAC - pi x TSF)2/4 pi] - 10, and [MAC - pi x TSF)2/4 pip] - 6.5. With two additional study groups, the overall improved accuracy of the new equations was confirmed, although the average error for a given patient was 7 to 8%; the relationship between corrected AMA and total body muscle mass was established [muscle mass (kg) = (ht, cm2) (0.0264 + 0.0029 x corrected AMA)]; and the minimal range of corrected AMA values compatible with survival (9 to 11 cm2) was defined. Bedside estimates of undernutrition severity and prognosis can therefore be calculated from two simple measurements, TSF and MAC.