The considerable amount of original and generic types of skinfold calipers available is a source of systematic measurement error. This study is a brief report that critically examines the original and illustrated structural configuration of the three main types of skinfold calipers. For more than half a century, the Harpenden®, Lange® and Slim Guide® skinfolds calipers have been widely used in clinical and research settings. It is well established that the physical, mechanical and functional specificity of each type of skinfold caliper makes its interchangeable use impossible. Our report suggests that commercially available technical specifications are insufficient to judiciously choose a skinfold caliper. The area of the jaws, the coefficient of spring and the static and dynamic downward pressure of each type of skinfold caliper must be determined in the metrological laboratory and added to the technical user manual. Choosing a type of skinfold caliper for regular use, without conflict of commercial interest, requires a critical understanding of the physical, mechanical and functional characteristics that configure it. Therefore, a new downward static calibration test and the first eligibility flowchart for a skinfold caliper have been proposed. Finally, the information gathered in this report may be useful for manufacturers of anthropometric instruments and health professionals who use the skinfold technique as a tool for diagnosis and nutritional control.

Parental and pregnancy characteristics can affect proportions and tissue composition of the child’s bodyand thereforecan influence their present and future health, as well as overall wellbeing. The aim of this study was to examine the differences between selected parental and birth-related parameters among preschool (3-7 years of age) children of varying adiposity status (n=541 girls and n=571 boys).The research was carried out in 20 randomly selected kindergartens in Krakow (Poland). Thickness of 6 skinfolds (biceps, triceps, subscapular, suprailiac, abdominal and calf) was measured. Sum of skinfolds was calculated and participants were divided into low, normal or high body fat groups. Birth-related characteristics were obtained using a questionnaire filled out by the children’s parents. Children of mothers who gained the most gestational weight were characterised by high adiposity. Preschoolers with the highest birth weight, body length and head circumference had the greatest adiposity. Children of relatively younger mothers had higher body fat, in comparison to the rest of the study group. Parents of preschoolers in the high adiposity category were characterised by a greater body mass, compared to the parents of children in other body fat groups and that boys with the highest adiposity relatively more often had a close relative with obesity. Children in varying adiposity categories differed in terms of some birth-related factors. Particular attention should be paid to familial and parental characteristics, because they may influence the child’s predisposition to excess adiposity deposition later in life.

Differences in physical activity (PA) might lead to long-term weight control. Studies on inverse relations between PA and changes in fatness among adolescents are limited. This paper examined the effect of PA on adolescents’ changing body fatness over 5 years in Ho Chi Minh City (HCMC). Two hundred thirty-five boys and 247 girls who have had skinfold thickness measurements in the baseline survey in 2004 were selected to follow yearly. We estimated PA as the average number of accelerometers’ counts/h. Slopes of triceps, sub-scapular skinfolds and BMI were calculated and classified as increasing or stable/decreasing. To assess the effects of the low level of activity (i.e. below the median of the average number of counts) on the fat gain (i.e. increasing slopes), relative risk and 95 % CI were estimated using Poisson regression. The average number of counts/h in boys (7·8) was significantly higher than that in girls (5·0) (P < 0·001). On average, active girls still gained 0·51 mm in triceps skinfold (TSF) over 5 years, while active boys lost 0·12 mm. After controlling for baseline energy intake, baseline triceps and baseline age, inactive adolescents were 1·39 times higher than active ones to increase the slope of triceps (95 % CI 1·19, 1·63). The risk ratio was 1·62 for those with more body fat at baseline. In general, inactive students gained substantially more subcutaneous fat, especially in their TSF, than more active ones. Thus, strategies to prevent adolescent obesity in HCMC should consider the important role of PA to control this problem in adolescents effectively.

The present paper will use fat mass percentage (FM%) obtained via BOD POD® air-displacement plethysmography (FMADP%) to examine the relative validity of (1) anthropometric measurements/indices and (2) of FM% assessed with equations (FMeq%) based on skinfold thickness and bioelectrical impedance (BIA). In 480 Belgian children (aged 5–11 years) weight, height, skinfold thickness (triceps and subscapular), body circumferences (mid-upper arm, waist and hip), foot-to-foot BIA (Tanita®) and FMADP% were measured. Anthropometric measurements and calculated indices were compared with FMADP%. Next, published equations were used to calculate FMeq% using impedance (equations of Tanita®, Tyrrell, Shaefer and Deurenberg) or skinfold thickness (equations of Slaughter, Goran, Dezenberg and Deurenberg). Both indices and equations performed better in girls than in boys. For both sexes, the sum of skinfold thicknesses resulted in the highest correlation with FMADP%, followed by triceps skinfold, arm fat area and subscapular skinfold. In general, comparing FMeq% with FMADP% indicated mostly an age and sex effect, and an increasing underestimation but less dispersion with increasing FM%. The Tanita® impedance equation and the Deurenberg skinfold equation performed the best, although none of the used equations were interchangeable with FMADP%. In conclusion, the sum of triceps and subscapular skinfold thickness is recommended as marker of FM% in the absence of specialised technologies. Nevertheless, the higher workload, cost and survey management of an immobile device like the BOD POD® remains justified.

Anthropometric data indicate that the human phenotype is changing. Today's adult is greater in stature, body mass and fat mass. Accurate measurement of body composition is necessary to maintain surveillance of obesity within the population and to evaluate associated interventions. The aim of the present study was to construct and validate generalised equations for percentage body fat (%BF) prediction from anthropometry in 1136 adult men and women. Reference values for %BF were obtained using dual-energy X-ray absorptiometry. Skinfold thickness (SF) at ten sites and girth (G) at seven sites were measured on 736 men and women aged 18–81 years (%BF 5·1–56·8 %). Quantile regression was employed to construct prediction equations from age and log-transformed SF and G measures. These equations were then cross-validated on a cohort of 400 subjects of similar age and fatness. The following generalised equations were found to most accurately predict %BF: $Men:\,(age\times 0\cdot 1) + (logtricepsSF\times 7\cdot 6) + (logmidaxillaSF\times 8\cdot 8) + (logsuprspinaleSF\times 11\cdot 9) - 11\cdot 3$$$ (standard error of the estimate: 2·5 %, 95 % limits of agreement: − 4·8, +4·9) $Women:\,(age\times 0\cdot 1) + (logabdominalG\times 39\cdot 4) + (logmidaxillaSF\times 4\cdot 9) + (logbicepsSF\times 11\cdot 0) + (logmedialcalfSF\times 9\cdot 1) - 73\cdot 5$$$ (standard error of the estimate: 3·0 %, 95 % limits of agreement: − 5·7, + 5·9) These generalised anthropometric equations accurately predict %BF and are suitable for the measurement of %BF in adult men and women of varying levels of fatness across the lifespan.

Children in China are experiencing a rapid increase in the prevalence of obesity, which is associated with hypertension. To compare the effect of body fat on blood pressure (BP) with that of the normal physical growth, we compared BP levels in Chinese children with different body fat levels. In the present population-based study, 13 972 children in the highest-skinfold-thickness-quartile group were individually matched to 13 972 children in the lowest-skinfold-thickness-quartile group by height and weight. Similarly, 5103 children in the highest-waist-circumference-quartile group were matched to the same number of children in the lowest-waist-circumference-quartile group. The high- and low-fat groups had similar height and weight but the high-fat group had significantly higher skinfold and waist circumference measurements. The differences in systolic BP (SBP) between the high- and low-skinfold-thickness groups were small: 0·01 (95 % CI − 0·41, 0·44) mmHg in boys and 0·20 (95 % CI − 0·15, 0·54) mmHg in girls. The differences in diastolic BP (DBP) were also small (0·39 and 0·38 mmHg for boys and girls, respectively) but were statistically significant. The differences in both SBP and DBP between the high- and low-waist-circumference groups were small but not statistically significant. For a given body size as measured by height and weight, relative body fat had little impact on BP levels in these children. Fat mass and lean mass may have a similar quantitative impact on BP in healthy-weight children.

The use of skinfold thickness measurements to evaluate the distribution of subcutaneous adipose tissue and to predict body fat has recognised advantages. However, the different types of skinfold calliper available present limitations that make them unattractive and perhaps less used in daily practice. The purpose of the present study was to evaluate the accuracy and functionality of a new digital skinfold system, the Liposoft 2008+Adipsmeter V0 (LA), for measuring skinfold thickness and determining body fat proportion (%BF). Skinfold thickness measurements made by the LA were compared with those obtained with a Harpenden (H) calliper from two samples of adults (n 45) and older adults (n 56) in a university-based cross-sectional study. A comparison was also conducted between estimated %BF from skinfolds and dual-energy X-ray absorptiometry. Bland and Altman plots show that skinfolds measured by the LA and H calliper are in high agreement, with a mean difference of 0·3 (95 % CI − 3·1, 3·4) mm. In regard to the %BF estimated from LA and H skinfolds measurement, the LA produced a similar approximation to dual-energy X-ray absorptiometry %BF, with a mean difference of 0·2 (95 % CI − 0·8, 1·2) %, compared with %BF obtained with the H calliper. The LA system is an accurate instrumentation and represents an innovation in the evaluation of skinfold thickness and body composition based on anthropometric measurement.

We evaluated the accuracy of skinfold thicknesses, BMI and waist circumference for the prediction of percentage body fat (PBF) in a representative sample of 372 Swiss children aged 6–13 years. PBF was measured using dual-energy X-ray absorptiometry. On the basis of a preliminary bootstrap selection of predictors, seven regression models were evaluated. All models included sex, age and pubertal stage plus one of the following predictors: (1) log-transformed triceps skinfold (logTSF); (2) logTSF and waist circumference; (3) log-transformed sum of triceps and subscapular skinfolds (logSF2); (4) log-transformed sum of triceps, biceps, subscapular and supra-iliac skinfolds (logSF4); (5) BMI; (6) waist circumference; (7) BMI and waist circumference. The adjusted determination coefficient () and the root mean squared error (RMSE; kg) were calculated for each model. LogSF4 ( 0·85; RMSE 2·35) and logSF2 ( 0·82; RMSE 2·54) were similarly accurate at predicting PBF and superior to logTSF ( 0·75; RMSE 3·02), logTSF combined with waist circumference ( 0·78; RMSE 2·85), BMI ( 0·62; RMSE 3·73), waist circumference ( 0·58; RMSE 3·89), and BMI combined with waist circumference ( 0·63; RMSE 3·66) (P < 0·001 for all values of ). The finding that logSF4 was only modestly superior to logSF2 and that logTSF was better than BMI and waist circumference at predicting PBF has important implications for paediatric epidemiological studies aimed at disentangling the effect of body fat on health outcomes.

Skinfold thickness (SF) measurements are commonly used for the indirect assessment of body composition. It is necessary to know how large the bias is when using Caucasian SF-based prediction equations Africans, as no specific equations exist. Our first aim was to test the validity of the equation of Durnin & Womersley for predicting body density from SF in Africans. The second aim was to determine the effect of calculating percentage body fat (%BF) from body density using a black-specific formula rather than the Siri equation, thus taking into account the higher fat-free mass (FFM) density in blacks than in whites. A total of 196 African women volunteered. Mean age was 29·5 (sd 8·7) years and mean BMI was 22·5 (sd 4·6) kg/m2. We compared body density values predicted from SF with those measured by air-displacement plethysmography, and %BF values obtained from body density using the Siri equation or the black-specific calculation. The bias (reference minus prediction) was 0·0100 kg/cm3 in body density (P<10−4) and 6·5 % BF (P<10−4), and the error (sd of the bias) 0·0097 kg/l and 4·5 % BF. With the black-specific equation, the bias was reduced by 1·9 % BF, while error remained similar. As the %BF prediction required an SF-based equation followed by a body density-based calculation, the lack of validity we observed in Africans may be due to known differences between blacks and whites in the distribution of subcutaneous adipose tissue and, as demonstrated, in the FFM density. Equations thus need to be established using SF values specific to Africans.

Skinfold thicknesses represent a comparatively simple and reasonably accurate assessment of body fatness which is an important part of the estimation of nutritional state. However, much emphasis is placed on the necessity to be very precise in the exact position of the skinfold being measured and there is frequently concern, also, about the variability of the measurement by different observers using different types of caliper. Fifty-three women and forty-five men had four skinfolds (biceps, triceps, supra-iliac and subscapular) measured first at the standard sites (Tanner, 1953; Edwards et al. 1955), and then at deliberately chosen sites about 20 mm distant from the ‘correct’ ones. The effect on the estimation of body fatness by this manoeuvre resulted in a difference of usually less then 1% and, at a maximum, 3%. In the light of the uncertainty of the basic assumptions which are made in extrapolating from skinfolds (or indeed densitometry, total body water, total body K, and others) to body fatness, these technical errors assume comparatively little importance.

The relationship of skinfold thicknesses to body density and of skinfold thicknesses to densitometrically determined body fat was evaluated in a group of 378 boys and girls, aged 7–20 years. According to their maturation level, they were divided into a prepubertal, a pubertal and a post-pubertal group. In each maturation group boys were older, had higher body-weights and body heights, higher body densities, lower percentage body fat, higher waist:hips ratios and higher trunk:total skinfolds ratios than girls. Body density in each maturation level could be quite precisely predicted by skinfold thicknesses. In prepubertal and pubertal boys and girls but not in post-pubertal boys and girls, age was also an important predicting variable for body density. The assessment of percentage body fat from skinfold thicknesses had a prediction error of 3–5 %, which was highest in the prepubertal children. The prediction error is comparable to the prediction error of percentage body fat from skinfold thicknesses in adults, as reported in the literature. Only in post-pubertal boys and girls was the waist:hip ratio correlated with measures of body fatness. Moreover, only in the post-pubertal boys and in the pubertal and post-pubertal girls was the waist:hips ratio correlated with another measure of body fat distribution, the trunk:total skinfold ratio. The relative amount of internal body fat was found to be higher in the younger maturation groups. It is concluded that at younger ages the waist:hips ratio is a poor indicator of body fat distribution.