Definition and diagnosis
Adiposity causes an increase of body fat to more than twice the normal level. At the same time body water levels will rise. At the same time a reduction of body cell mass (BCM) is observed. Thus for example the body composition of a morbid obese person of doubled body weight could be as described in Table 1, compared to a man of normal weight and same height.
Diagnosis is made rather easily by considering patients' height and weight. The current internationally recognised calculation value is called BMI (Body Mass Index, Kg /m2), and is calculated by dividing body-weight in kilograms by the square of the height (m2).
The BMI was introduced in the 18th century by the Belgian Quetelet. It is much more suitable than the Broca-number (ideal weight according to Broca = body height in centimetres minus 100 in kilograms) which at best provides a rough estimate, since its conventions are very strict on males, small and old people, yet evaluate tall and young people mostly too favourably, and is not applicable to children at all.
| Kg | % | Kg | % | |
|---|---|---|---|---|
| Weight Total BMI |
70 24 kb/m2 |
100 | 140 48 kb/m2 |
100 |
| Water | 42 | 60 | 52 | 37 |
| Proteins | 12 | 17 | 20 | 14 |
| Fat | 12 | 17 | 63 | 45 |
| Minerals | 3.5 | 5 | 4.2 | 3 |
| Carbohydrates | 0.5 | 0.7 | 0.8 | 0.6 |
| Tab. 1: Body composition at 70, respectively 140kg body weight and 1.7m height | ||||
Adiposity is defined as a disease by the WHO (World Health Organization). A panel of WHO experts issued a classification to this effect in 1995. At normal weight the BMI is 18.5 – 24.9kg /m2, in obese people 25 – 29.9, in grade I adipose people 30 – 34.9, in grade II adipose people 35 – 39.9 and in grade III adipose people, which is synonymous with morbid adiposity, it is above 40. It is also defined by excess weight of 45 kilograms and more, or 180% of the normal (ideal) weight. Two main types of obesity (adiposity) have been known for quite some time, though their meaning was rather unclear:
1. Gynoid adiposity ("pear-shaped"): Fat distribution mainly to the hips and thighs. Concomitant, respectively secondary diseases are diagnosed often but in their mild forms.
2. Android adiposity (visceral fat type, "apple shaped"): Centric fat distribution patterns with increased disposition towards the abdominal area. This form constitutes a severely increased health risk compared to the gynoid adiposity, with increased comorbidity The visceral fat tissue seems to be more endocrinic and metabolically active compared to the peripheral-gynoid type which is associated with less severe health risks. Both types can be distinguished by their associated body appearance, and adequately determined by using a measuring tape. When doing so circumference is measured just above the navel and above the hips in an upright standing position. These two values are used to calculate the quotient (=T-H-quotient, Waist-Hip-Ratio =WHR, see Table 2). Due to the significantly increased risk of secondary diseases with the android type, gender-specific threshold values for the hip circumference may be deduced (s. Tab. 3).
| Waist-Hip-Ratio | |
|---|---|
| Males | > 1 |
| Females | < 0.85 |
| Tab. 2: Waist-hip ratio for the android adiposity type | |
| RISK | Increased risk level | Severely increased risk level |
|---|---|---|
| Males | > 80 cm | > 88 cm |
| Females | > 94 cm | > 102 cm |
| Tab. 3: Hip circumference increased comorbidity risk threshold values | ||
| ||||||||||||||||||||||||
| Tab. 3: Hip circumference increased comorbidity risk threshold values | ||||||||||||||||||||||||