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Obesity Surgery, 17, 565-568
Weight loss, although certainly not the only criteri-
on, is an important outcome measure after bariatric
surgery. However, as the years go by and health con-
ditions in society change, it is important to review
the current situation.
In 1959, the Metropolitan Life Insurance Company
released tables of the best weight for each height for
longevity, based on collected insurance data.1These
were called the “desirable” weights.
In 1983, the Metropolitan Life Insurance
Company in New York released the “ideal” weights
for greatest longevity (or for lowest mortality).2
These were based on the Build Study of 1979, deter-
mined by the Society of Actuaries in Chicago, on
patients followed for 18 years (1954-1972).3This
data was collected from 25 life insurance companies
in the USA and Canada, representing 4.2 million
insured individuals, and is still by far the largest
study available. The “ideal” weights were higher
than the prior “desirable” weights, and this was
attributed to an increase in muscle mass due to
improved fitness.2The average weights in the popu-
lation are higher than the ideal weights for survival.
The criticisms of the 1983 Height and Weight
Tables were:41) the insured population tended to be
affluent and white; 2) 10% of the weights were self-
reported; 3) the weights included indoor clothing,
estimating 5 lbs for men and 3 lbs for women, and
shoes with 1 inch heels in both men and women; 4)
individuals with known heart attacks, cancer, dia-
betes and hypertension were excluded.
The ideal weight was based on the mean weight of
the insured individuals age 25-59, but ideal weight
for survival actually increased up to age 54.3
The Metropolitan Tables included small, medium
and large frames, based on elbow-girth using
calipers,5because the elbows do not develop adi-
posity. The elbow-girth from the 15th to 85th per-
centile was termed the medium frame.
The Tables presented weight ranges for height,
sex and body frame, associated with the lowest mor-
tality. The mid-point of the ideal weight range for
the medium frame for each height was selected as
the ideal weight for calculations.
Excess weight (initial weight – “ideal” weight) was
the weight above “ideal” weight. From this, the wide-
ly used equation became available: percent excess
weight loss (using the initial excess weight) or
%EWL =preoperative weight – current weight x100.
preoperative weight – ideal weight
An easy formula to calculate the “ideal” weight is
shown in Table 1.6
%EWL has been widely used. However, this is
based on 1979 data. People are now living longer.
The ideal weight associated with maximal longevi-
ty has increased,7likely due to earlier diagnoses,
medications, improvements in public health and
medical care, and the effect of the fitness industry
on muscle mass.
However, this current finding of increased longevi-
ty at higher weights may in the future become negat-
ed due to the occurrence today of obesity and its relat-
ed morbidities in adolescents and teenagers,8where
we now have a generation which may not live as long
as its parents.9In any event, the %EWL, widely used
in the USA and many other countries by bariatric sur-
geons, has lost considerable accuracy by 2007.
Reporting Weight Loss 2007
Table 1. Formula for calculation of Ideal Weight6*
Adult Female:5 ft.tall = 119 lb.For each additional inch, add 3 lb.
Adult Male: 5 ft. 3 inches tall = 135 lb. For each additional inch,
add 3 lb.
1 foot = 30.4 cm; 1 inch = 2.54 cm.
Divide lb. by 2.2 to change to kg.
*Formula corresponds to mid-point of medium frame of the
Metropolitan Tables, with accuracy within 1%. To convert to
ideal weight for small or large frame, decrease or increase the
result by 10%. Patients without shoes.
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