4. www.DexaFit.com
3727 North Broadway Street
Chicago, IL 60613
DexaFit@gmail.com
(312) 650-9856
Fat Mass Index
FMI Severe Moderate Mild Fat Normal Excess Fat Obese Class I Obese Obese
Class Fat Fat Deficit Deficit Class II Class
Deficit III
Male <2 2 to <2.3 2.3 to <3 3-6 >6 to 9 >9 to 12 >12 to >15
15
Female <3.5 3.5 to <4 4 to <5 5-9 >9 to 13 >13 to 17 >17 to >21
21
Fat Mass Index (FMI) vs. BMI: Currently, BMI is the standard measure for clinical obesity. One advantage of
FMI over BMI is that it amplifies the relative effect of weight loss or gain on body fat based on different
variables: aging, crash diets, height, etc. Expression of a change in body fat in absolute value fails to allow an
appropriate comparison among subjects of different sizes or backgrounds.
Where BMI may fail to change substantially because of an associated physical activity program (e.g., strength
training), the body’s fat mass may substantially decrease, and hence the FMI as well. The high sensitivity of
FMI to a slight change of body fat stores and lean mass, compared to the BMI or percentage of total body fat,
makes it more valuable for assessing static and dynamic nutritional status and body composition health.
Problems with BMI (Weight/Height^2) Advantages of FMI (Fat Mass/height^2)
Measure of excess weight, not excess fat Measure of excess fat not confounded by
Not gender specific lean mass
Same reference values for both genders Gender specific reference values
Muscle Symmetry: A lean mass difference close to zero indicates a balance of muscle. An injury, non-
symmetrical training, or health condition may cause a disproportionate lean mass difference.
Android and Gynoid Fat: When in lean and peak condition, android fat (i.e. belly/visceral fat) should be
around 60-65% of gynoid fat (i.e. hips, thighs, and buttocks). When out of shape and overweight, android fat
can exceed gynoid fat—a possible precursor to disease if it continues to increase or stay the same over time.
A/G Ratio: The android to gynoid ratio is directly correlated to the prevalence of visceral fat, which is a result
of organs insulating themselves from toxins by encapsulating the toxins in fat. This survival strategy may
impede organ function and increase the risk for heart disease, stroke, and metabolic syndrome. Ideally your
android fat will be lower than your gynoid fat (a ratio below 1.0).
Target Fat Loss: Your target fat loss is the amount of fat mass you need to lose (assuming lean mass stays the
same) to reach your target fat percentage.
A/G Ratio
Optimal 0.8 Target 1.0 Risk 1.2 Risk
http://www.ncbi.nlm.nih.gov/pubmed/20737611
http://www.nature.com/ijo/journal/v26/n7/abs/0802037a.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2929934/
5. www.DexaFit.com
3727 North Broadway Street
Chicago, IL 60613
DexaFit@gmail.com
(312) 650-9856
Female Body Composition Values by Age:
Age Range Mean Age BMC (g) Tissue (%fat) Region Android Gynoid A/G Ratio
(%fat) (%fat) (%fat)
18-29 22.5 2626 28.6 27.4 31 38 0.8
30-39 35.5 2523 30.9 29.6 34.6 39.9 0.85
40-49 45.4 2653 33.3 31.9 37 41.6 0.87
50-59 54.6 2479 34.9 33.6 38.7 43.2 0.89
18-59 40 2580 32.1 30.8 35.4 40.8 0.85
Male Body Composition Values by Age:
Age Range Mean Age BMC (g) Tissue (%fat) Region Android Gynoid A/G Ratio
(%fat) (%fat) (%fat)
18-29 22.7 3308 13.8 13.2 17.7 18.1 0.94
30-39 35 3534 22.8 21.8 31.5 28.4 1.11
40-49 44.4 3226 19.3 18.6 23.8 20.5 1.04
50-59 54.0 3304 24 23.1 32.2 26.9 1.17
18-59 32.9 3314 17.3 16.6 22.5 21 1.01
BMD and Body Composition Values of College Runners, Swimmers, and Baseball Players:
Region BMD (cm²) BMC (g) Fat (lbs) Lean (lbs) %Fat
Arms
Runner 1.043 491 2.21 17.64 10.6
Swimmers 0.992 478 2.87 18.96 12.6
Baseball Players 1.125 524 4.41 18.96 17.8
Legs
Runner 1.531 1400 8.16 46.74 14.0
Swimmers 1.314 1183 10.8 45.42 18.3
Baseball Players 1.538 1426 16.3 48.50 24
Trunk
Runner 1.152 991 8.61 65.26 11.1
Swimmers 1.077 984 13.01 68.34 15.4
Baseball Players 1.225 1111 21.16 67.02 22.7
Android
Runner — — 0.88 9.04 9.8
Swimmers — — 1.76 9.26 15.4
Baseball Players — — 3.53 9.04 26.0
Gynoid
Runner — — 3.11 21.61 12.2
Swimmers — — 5.29 21.16 20.1
Baseball Players — — 9.04 21.16 29.3
Total
Runner 1.371 3417 20.72 137.13 12.5
Swimmers 1.247 3178 28.89 140.88 16.2
Baseball Players 1.414 3604 43.87 142.42 22.2
*Dr. Mary K. Oates: http://dxabodycomp.com/medical_research.php