[Body mass index (BMI) and percent fat mass. A BMI > 27.5 kg/m2 could be indicative of obesity in the Spanish population].
BACKGROUND
The World Health Organization (WHO) defines obesity as a condition of excessive fat accumulation to the extent that health and well-being are affected. For population studies, the measurement of weight, corrected for height, is still the method of choice (BMI). In Caucasian populations, the BMI cut-off point for obesity (30 kg/m2) corresponds with a percent body fat (PFM) of over 25% in young adult males and 35% in young adult females. However, the relation between BMI and PFM is not uniform among populations. It is important to define in each population the threshold of BMI which corresponds to the definition of obesity.


METHODS
BMI was calculated in 282 subjects. PFM was analyzed using Bio-electrical impedance. Blood pressure, serum glucose and insulin, and the fasting insulin resistance index were also determined in all subjects to analyze the metabolic impact.


RESULTS
The PFM of 25% in males and 35% in females corresponded to a BMI of 27.5 and 27.4 kg/m2, respectively. The slope of the relationship between the degree of obesity and comorbilities (insulinemia, fasting insulin resistance index and blood pressure) was strengthened above 26 kg/m2 in men and 24 kg/m2 in women.


CONCLUSIONS
BMI that corresponds to a PFM previously defined as obesity is lower in our population in comparison with other Caucasian populations. Our results confirm that is impossible to compare the prevalence of obesity among populations using exclusively the BMI. It will be important to define, using reference methods, whether these findings have physiological impact or not, and if this cut-off of BMI determines an increment in cardiovascular and overall mortality using epidemiological approaches.
Fernández-Real
J M
JM
Unidad de Diabetes, Endocrinología y Nutrición, Hospital Universitario de Girona, Laboratori Hormonal, Hospital Clínic i Provincial, Barcelona, Spain. endocrino@htrueta.scs.es
Vayreda
M
M
Casamitjana
R
R
Saez
M
M
Ricart
W
W
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D009752:Nutritional Status; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*; D011446:Prospective Studies; D017678:Sex Distribution; D013030:Spain / Q000453:epidemiology