Mar 27, 1991 - (trial. FIG I. The nomogram for determining body mass index as published inaccurately in The. Surgeon. General's. Report on Nutrition and.
ry
A major error in nomograms index1’2 Henry
for estimating
S Kahn
ABSTRACT The Surgeon General’s Report on Nutrition and Health and Diet and Health include a nomogram for determining body mass index (BMI, in kg/rn2) when the subject’s weight and height are known. I regret to report that the BMI in nomograms in these
books
calculations
are highly of BMI.
inaccurate
Anyone
on the versions 199 1;54:435-7. KEY
WORDS
grams,
body
ofBMI that appear
compared
150
direct
280
120
260
110
240
100 95
220
nomostandards,
90
200
,
inaccurate
that the BMI nomograms compared
199 l;54:435-7.
Printed
with
and
65
mass
190
Women
130
170
Obese
ruler (deval-
140
145
50 -40
Men 150
160 150 140
55
120
50
110
the
Obese
60 155
:30
Overweight
Overweight
Acceptable Acceptable
-
160 165
-20 170 175
45
100
70
95
two
180
40 185
85 80
in these books are
© 1991 American
r
130
-10
35
190
75 195
70
direct
in USA.
50
[wt/(ht)2]
are
calculations of BMI. The Surgeon General’s nomogram was attributed to a 1985 publication by George A Bray (3). By comparison, Professor Bray’s original nomogram performs quite well. A set of trial calculations of the BMI (Table 1) demonstrates the nature of the inaccuracy. Visual inspection ofthe nomograms reveals that Bray’s original version has substantially more blank space (left to right) between its central column (BMI) and its right column (height) than it has between its central column and its left column (weight). By contrast, the nomograms in The Surgeon General’s Report and Diet andHealth are displayed symmetrically on the page. Perhaps the graphic layout artists who produced the book-version nomograms were more interested in symmetry than in scientifIc or mathematical accuracy. As a result of thisgraphic modification, the book-version nomograms are accurate only when the connecting straight line between the weight and height variables is relatively horizontal on the page (trial subjects 3, 5, and 7). If the connecting straight line slopes up to the right (trial subjects 1, 2, and 4), then the book-version nomograms result in BMI values that are too high. If the connecting straight line slopes down to the right (trial
Am J C/in Nutr
when
125
80
70
The Surgeon General’s Report on Nutrition and Health Diet and Health include a nomogram for determining body index (BMI, in kg/m2) when the subject’s weight and height known (Fig 1 ) ( 1 2). To use this nomogram, one places a or other straight edge between the left column for weight scending values) and the right column for height (ascending ues) thereby connecting an individual’s numbers for those variables. The BMI is read where the straight line crosses middle column (BMI in descending values).
in
135
overweight
I regret to report
340 320
130
cm
Body Mass Index
140
for against relying Am J Clin Nutr
index, anthropometry, height, obesity, reference
mass
body
with
kg lb
a nomogram
to use
should be cautioned in these books.
Body
weight,
wishing
when
Height
Weight
30
25
200 60
205
55
210
80
85 0
FIG I. The nomogram for determining body mass index as published inaccurately in The Surgeon General’s Report on Nutrition and
Health (1). subjects 6, 8, and 9), then the book-version nomograms result in BMI values that are too low. Anyone wishing to use a nomogram for the rapid estimation of BMI should be cautioned against relying on the versions that appear in the Surgeon General’s report and Diet and Health.
From the Department of Community
and
Preventive
Emory University School of Medicine, Atlanta. 2Addr reprint requests to HS Kahn, 69 Butler Street,
Medicine, SE, Atlanta,
GA 30303-3219. Received March 26, 1991.
Accepted
Society for Clinical
for publication
Nutrition
March 27, 1991.
435
Downloaded from www.ajcn.org by guest on October 14, 2011
the rapid estimation
highly
body mass
436
KAHN
TABLE I A comparison weight
of direct
and
computation
with three
different
nomograms
for the estimation
of body
Hypothetical measurements Trial subject
Weight
I
2 3 4
5 6
7 8 9 a
Height
kg
in
50 50 50 80 80 80 110 110 110
1.35
Direct computation
Bray’s nomogram
27.43 20.81 16.33 43.90 33.30 26.12 60.36 45.79 35.92
27.5 20.8 16.2 43.5 33.0 26.0 59.2 46.0 36.0
1.55 1.75 1.35 1.55 1.75 1.35 1.55 1.75
hypothetical
measurements
of
index*
Diet and Health nomogram (2)
Surgeon General’s nomogram (1)
(3)
31.3 22.3 16.2 47.0 32.7 24.0 60.5 42.5 31.0
31.1 21.8 15.9 46.5 32.4 23.8 59.5 42.1 31.1
ment
ofHealth and Human Services. The Surgeon Genreport on nutrition and health. Washington, DC: US GovernPrinting Office, 1988. [DHHS (PHS) publication 88-50210.]
Comments
by George
A Bray’
2. National Research Council. Diet and health. Implications for reducing chronic disease risk. Washington, DC: National Academy Press, 1989. 3. Bray GA. Obesity: definition, diagnosis and disadvantages. Med J Aust l985;142(suppl):S2-S8.
was attributed
to me (1, 2) but was incorrectly redrawn by the Office and included in The Surgeon General’s Report on Nutrition (3) and the Diet and Health report of the National Research Council (4). I have sent a correct version of Surgeon
I owe
a debt
of gratitude
in a nomogram
to Henry
Kahn
for determining
body
for pointing
out
mass
which
index,
an
General’s
the nomogram error.
--
From
the Pennington
Biomedical
Research
Center,
Baton
Rouge,
LA.
TABLE I Estimation of body
mass
index
from
several
nomograms
compared
in Newsweek, these sources.
with calculated
values Body
Accurate
Weight
m
kg
1.52 1.52 1.52
45.4 68.2 90.9
1.65
54.5
1.65 1.65 1.78 1.78 1.78 In kg/rn2.
81.8 109.1 68.2 100.0 140.9
Calculated
19.6 29.5 39.3 20.0 30.0 40.0 21.56
May
asking
two erroneous
1990,
for several
mass
organization
to these
is also
height
incorrect
and weight
them
versions, because
to correct
Inaccurate Surgeon General’s report (3)
their
the nomogram it came
values
index5
versions Bray
Height
to each
In addition
versions
Diet and Health (4)
(1, 2, 5, 6)
Bennion et al. (7)
19.3 29.2 38.9 19.8 30.0 40.0 21.5
19.5 29.5 38.9 19.8 30.0 39.8 21.5
21.5 30.0 38.0 20.0 28.2 35.8 20.2
21.2 29.5 37.5 20.0 27.8 35.5 20.2
31.5
31.6
31.2
27.8
27.5
44.5
44.5
43.8
37.0
37.0
from
Downloaded from www.ajcn.org by guest on October 14, 2011
eral’s
*
using
In kg/rn2.
1. US Department
I
index
Body mass
References
error
mass
height
ERRONEOUS WEIGHT
CMIN
BODY MASS INDEX
_______
ISO
320 40 30
300 280
[WT/
( HT)2J
20
250
70
110
240
#{149} SO
00
220
90 .5
200 90
so
ISO
50 130
ISO
#{176}
OBESE
55
MEN
:: ::
OVERWEIGHT
4CC(PTA8L(
____________
OVERWEIGHT
o
4PTA8L(
:
110
170
45
100
175
40
95 90
ISO
55
55 50
which
was
findings
(2) and error,
originally
the
and
several
correct
copyrighted
show
other version
in 1978
in
copies of the
( 1 ), is re-
1). To avoid errors in reproduction of this prints are made available upon request.
References Bray
4.
0
55
5
report
ment
Printing
.
200 SO
205 55 210 55
FIG I. A nomogram for determining body mass index. To use this nomogram, place a ruler or other straight edge between the body weight in kg or lb (without clothes) located on the left-hand line and the body weight in cm or in (without shoes) located on the right-hand line. The body mass index is read from the middle of the scale and is in metric units.(Copyright 1978 George A Bray.)
on nutrition Office,
Research chronic
Am
and
and
health.
1980
[DHHS
Council.
Diet
disease
Press, 1989. Bray GA. Classification North
30
SO
measurements
classifications
ofthe
syn-
risk.
Washington, (PHS) and
Washington
and evaluation
DC:
publication
health. DC:
Implications National
of the obesities.
US Govern88-502
10.] for
re-
Academy
Med Clin
1989:73:161-84.
6. Bray GA. Overweight and fat distribution-basic consideration and clinical approaches. Dis Mon 1989:7:451-537. 7. Bennion U, Bierman EL, Ferguson JM, Editors of Consumer Report Books. Straight talk about weight control. Mount Vernon, NY: Consumers Union, 1991.
Downloaded from www.ajcn.org by guest on October 14, 2011
ISO
Definitions,
eral’s
ducing
I 55
70
GA.
National
70
75
50
Kahn’s
nomogram
dromes ofobesity. Int J Obes 1978;2:99-l 13. 2. Bray GA. Obesity: definition, diagnosis and disadvantages. Med J Aus 1 985: I 42(suppl):S2-S8. 3. US Department ofHealth and Human Services. The Surgeon Gen-
55
50
25
1 confirm
the original
(5, 6, 7). To avoid
nomogram,
I.
OBESE
30
40
in Table
that
printed here (Fig nomogram, glossy
ISO
ISO
65
437
BMI
35
(70
TO
data
accurate
are
25
40
WOMEN
The addition
50
75
FOR
HEIGHT
KGLB I
NOMOGRAMS
