Body mass index reference curves for the UK, 1990.

Abstract

Reference curves for stature and weight in British children have been available for the past 30 years, and have recently been updated. However weight by itselfis a poor indicator of fatness or obesity, and there has never been a corresponding set of reference curves to assess weight for height. Body mass index (BMI) or weight/height2 has been popular for assessing obesity in adults for many years, but its use in children has developed only recently. Here centile curves for BMI in British children are presented, from birth to 23 years, based on the same large representative sample as used to update the stature and weight references. The charts were derived using Cole's LMS method, which adjusts the BMI distribution for skewness and allows BMI in individual subjects to be expressed as an exact centile or SD score. Use of the charts in clinical practice is aided by the provision of nine centiles, where the two extremes identify the fattest and thinnest four per 1000 ofthe population. (Arch Dis Child 1995; 73: 25-29) Keywords: body mass index, growth reference, overweight, underweight. Another weight for height index suitable for the age group 4-12 years has been proposed by Chinn et al,6 based on its correlation with skinfold thickness. Defined as (weight (kg) -9)/ height (cm)3-7, it has the dual properties that its mean and coefficient of variation are both unrelated to age. This means that it does not need adjusting for age. MRC Dunn NutritionA very flexible index of overweight is provided by the power function weight/heightn, where n the power of height usually takes values in the range 1 to 3. Restricting it to whole numbers, the value for n which best adjusts weight for height, and at the same time removes most of the trend of increasing weight with age, is n=2.7 8 This leads to the body mass index (BMI) weight/height2, also known as the Quetelet index9 or the Kaup index.'0 BMI has been used widely in adults for the last 25 years as a simple summary measure of overweight," 12 but its use in childhood has developed relatively recently. Adult BMI increases fairly slowly with age, so that age independent cut offs can be used to grade obesity.'3 In children, however, BMI changes substantially with age, rising steeply in infancy, falling during the preschool years, and then rising again into adulthood. For this reason, child BMI needs to be assessed using age related reference curves.Such curves have been published for French8 14 and American'5 16 children, but they are all imperfect, either because the data are old or the age range is restricted. This paper provides up-to-date reference curves for BMI in UK children, covering the age range birth to 23 years, and presented as nine centiles. They are among the first such curves to complement existing national references for weight and height based on the same dataset. Methods SUBJECTSThe reference sample of children was obtained by combining data from 11 distinct surveys. The data were collected between 1978 and 1990, a long enough period of time for the...

Clinical efficacy of group-based treatment for childhood obesity compared with routinely given individual counseling

“…BMI increases physiologically, though slowly, in school children. 22 Therefore, beneficial changes in children's weight status may not be seen if age-related references are not in use, as is the case in our country. To overcome this problem, we calculated BMI-SDS values, and applied British population-based references.…”

“…The Pediator-program, 20 based on Finnish national growth charts, was used to assess weight for height. In addition, body mass index (BMI) was calculated by using the formula {weight (kg)/[height (m)] 2 }, and BMI BMI, body mass index; BMI-SDS, BMI standard deviation score (calculated based on the British reference 22,23 ). There were no statistically significant differences between the treatment programs, analyzed by independent samples t-test for continuous and by w 2 test for discrete variables.…”

“…21 The calculator uses the British gender-specific growth reference from 1990, produced by the LMS method, 22,23 and revised in 1996. 24 The LMS method summarizes the distribution of BMI at each age by its median (M), coefficient of variation (S) and a measure of skewness expressed as a Box-Cox power (L) required to transform the data to normality.…”

“…26,27 Since corresponding national, population-based BMI references are not available, BMI and BMI-SDS were used as secondary outcome measures in this study, and the calculation of BMI-SDS was based on the British reference. 22,23 The pre-treatment weight for height was used also as the post-treatment value for one drop out (group treatment), and the weight for height measured a month earlier by the school nurse for one child who did not participate in the post-treatment health examination (routine treatment).…”

Pediatric obesity is associated with an altered gut microbiota and discordant shifts in Firmicutes populations

“…Briefly, children's BMI was calculated by reported weight/height 2 (kg m −2 ), and classification of obese (O) and normal weight (N) was made according to Cole (Cole et al ., 2000). Weight (kg), height (cm) and BMI (kg m −2 ) were transformed to age and sex‐specific z ‐scores (Cole et al ., 1995). Inclusion criteria were: children living in Northern Italy born from Caucasian parents with birth weight ≥ 2500 g, gestational age 37–42 weeks and singleton birth.…”