|
| Method | Underlying principle | Reliability (+ to +++) | Availability and cost | Advantages/disadvantages |
|
| Anthropometric methods |
| BMI | Weight/height2 | +
Inaccurate | The most used metric of obesity
Costless | Cheap and it does not require special equipment |
| Skinfold thickness | Thickness of the skin at various body areas | ++
Accurate but the operator needs specific training | Costless | Costless |
| Waist circumference and waist-to-hip ratio | Circumferential measurements of the abdomen and the hip | ++ | Costless
Superior to BMI for prognostic purposes | Cheap and it does not require special equipment |
| Body adiposity index | An index based on the hip circumference and height measurements | ++ | Costless | Cheap and it does not require special equipment |
|
| Machine-based methods |
| Underwater weighing | Body density | +++ | For clinical research only, expensive | Cheap |
| Air displacement plethysmography (ADP) | Body density. | +++
But not practical and required specialized person | For clinical research only, expensive | It is highly expensive and demands special apparatus and the use of compression underwear |
| Dual-energy X-ray absorption | The intensity of the X-ray is associated with the density, thickness and chemical composition of the crossed object | ++
Frequently used as a gold standard | Used mainly in clinical research, expensive | It requires taking an appointment with a medical professional in a clinic |
| Computed tomography (CT) | Transmitted intensity of X-rays | ++
Mainly used as a gold standard | Used for clinical research only, highly expensive | Used for clinical research only, highly expensive |
| MRI | The relaxation time for protons in fat is much shorter than that for protons in water | +++
Mainly used as a gold standard | Used for clinical research only, very costly | Used for clinical research only, highly expensive |
| BIA | Based on the fact that fat is a relatively nonconductive tissue
Impedance analysis | + to ++ | Instruments of various cost and reliability
Multifrequency instruments
Quiet and well validated | It does not need high technical skills to perform the impedance measurement |
| Near-infrared interactance | Optical densities are linearly and inversely related to percentage body fat | + | Inexpensive but insufficiently accurate | Its results in percent fatpredictability are slightly better than BMI |
|
