[Prevalence of obesity in Spain: the SEEDO'97 study. Spanish Collaborative Group for the Study of Obesity]

The weight distribution of a random sample of Spanish population aged 25-60 years is described. The prevalence of obesity and overweight is estimated by sex, age group and cultural level.

Weight, height and waist to hip ratio (WHR) were measured on 5,388 subjects aged 25-60 yr who participated in population Nutritional surveys carried out in four Spanish autonomous regions (Cataluña, País Vasco, Madrid and Valencia) from 1989 to 1994. They were pooled together in order to build a national random sample. The sample was classified according to body mass index (BMI) (weight in kg/height in m2). Obesity was defined as BMI > or = 30 kg/m2. The prevalence of obesity by sex, age group and cultural level was estimated. Risk values for WHR were defined as WHR > 1 for men and WHR > 0.9 for women.

The prevalence of obesity was 13.4%, 11.5% among men and 15.2% among women. Obesity increased with age in men and women, from 5.3% in the 25-34 yr group to 26.3% in the age group 55-60. Among those with a BMI > or = 30, 30.7% of men and 25.1% of women had also risk values for WHR. Educational level showed an inverse relationship with obesity, thus obesity was higher in less educated groups, particularly among women (p < 0.001). The geographical distribution of obesity showed a south-southeast trend, significant for males (p < 0.001).

Prevalence of obesity in Spain was 13.4%, higher after 45 yr of age, particularly in women and less educated groups.