You only have to look at college or Olympic wrestlers, both at 8% body fat, to know that at a given weight class, say 163 lbs, you can have one at 76", and one at 63". So the weight tables are useless in this case. So, you go to taping to guesstimate body fat. I say guesstimate because neither the weight tables, nor the taping, actually measures body fat. They are both estimates based on national averages. So you tape both of these wrestlers... the 74" wrestler is OK via the height weight standrds in AR 600-R. The 63" wrestler is of a very stocky build, plus has added about 30 lbs of lean muscle to his frame with training. The 63" wrestler's chest is big and round, and so too is his abdomen... but with 10% body fat. The 63" wrestler fails the taping test, not because of body fat % (which at 10% is at half of the allowable 20% for 21 yr. old males), but because of a body shape that is statistically uncommon.
My point is, if body fat % is the metric, then measure body fat % the correct way, not by using statistical tables form MetLife from 1928 (or whatever year it was), or taping abdomen-neck for men, or abdomen+hips-neck for women, that doesn't take into account the SHAPE of a very stocky body vs. a very thin one --- let's say the outer edge 10% of the statistical curve for both thinness, or stockiness, at a given body fat %. For a female, the current taping method makes no accounting for the different shape of the gluteal or thigh muscles (this area is not measured for males). Some have thin gluts and thighs (sort of like a long distance runner), some very large gluts and thighs, sort of like a weight lifter.
Take two 66" female cadets with 25% body fat (as measured by a scientific body fat % method that takes into account body shape). The thin body shape has measurements of 13neck,27"waist,39" hips. This thin body shape cadet shows 25% body fat per the taping tables in AR 600-9. The stocky cadet's measurements are 14neck,27"waist, 45" hips. The stocky cadet has 31% body fat per the taping tables, almost completely because she has muscular gluts and thighs. Per the taping guesstimate tables, the runner is in the middle of Standard at 25% BF%, and the stocky cadet is overweight at 31% of BF%.
I was curious and googled "measuring body fat %" and found this page that describes about ten ways of measuring body fat %. None of the methods involves a height/weight statistical table, or a tape measuring statistical table.
http://new-fitness.com/body_fat_analyzing.html
I am not criticizing the goal of having soldiers combat ready and physically healthy. Nor am I commenting on the limits --- that for a 21 year old, 20% is the upper limit for a male, and 30% for a female. Every soldier, whether serving in a field hospital, or in an intelligence office in Virginia, needs to be available and ready to deploy into front line combat, or any other area where physical fitness is a requirement... ie. there really are no "desk jobs", and lives could be on the line at any moment. Body fat % is a critical part of that objective.
I
am saying that if good people who want to serve, enlisted or commissioned, and are outside the guesstimate height/weight tables or outside the guesstimate taping method, then go to the next step and truly measure their body fat % in the scientific way... with the water tank, MRI, or any of the methods described in my link above. It just doesn't make sense to guesstimate by either imprecise method in a matter that is so critical to careers.