Body mass index and obesity in children with cerebral palsy
RICHARD D STEVENSON
University of Virginia School of Medicine – Pediatrics, Charlottesville, VA, USA.
This commentary is on the original article by Duran et al. on pages 680–
686 of this issue.
Childhood obesity has reached endemic proportions over
the past 30 years
and the rate of obesity among children
with disabilities has been reported to be even higher. The
primary tool used to identify obesity is body mass index
(BMI). Deﬁned as the ratio of weight in kilograms divided
by the square of height in meters, BMI is used as an inex-
pensive and widely available surrogate measure of adiposity
or fatness. Clearly, BMI is a measure of weight (fat and
lean components) in relation to height rather than a direct
measure of fatness. Because of changes with growth, BMI
is only a moderately sensitive and speciﬁc indicator of
excess fatness in typically developing children with high
and determining relative fatness among normal
weight children is not possible with BMI alone. BMI in
children with cerebral palsy (CP) is even more problematic
due to the known inaccuracies of measurement. Critically,
obesity in children is strongly associated with negative
health consequences; it may also impact physical function-
ing in those with disabilities.
Duran et al.
report on the performance of BMI to iden-
tify excess body fat in children with CP. Their most
important ﬁnding is the signiﬁcant number of children
with excess fat who have normal weight (and normal BMI).
They correctly point out that monitoring only BMI may
lead to a failure to identify such children (and dietary man-
agement with only an eye on BMI and weight gain can
lead to iatrogenic obesity).
So where does this leave the clinician? Obesity has been
shown to be a signiﬁcant problem in children and adults
with disabilities, with negative impact on health. Impor-
tantly, obesity is potentially preventable and modiﬁable. It is
time to go beyond BMI in the care of children with CP. We
need to implement valid, reliable tools to better serve
patients. Such tools are available and have already been
Skinfold thickness measurement directly assesses
body fatness; it is a simple test that is quick, reliable, and fea-
sible in a clinical context. It requires training and calipers
typically used in research are expensive so it has not been
widely implemented thus far. Bioelectric impedance and
dual-energy X-ray absorptiometry are also validated options,
but each with its own limitations. Alternatively, waist-to-hip
circumference ratio may be useful, as it has been associated
with cardiovascular risk in adults with CP.
We must implement known methods to identify excess
fatness and combine them with tools to measure health,
mobility, function, and well-being. Future research must
focus on the relationship between fatness and health or
function across the lifespan and the development of inter-
ventions to improve the health and well-being of those
with CP. Otherwise, we may unwittingly contribute to
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