Time trends in obesity: an epidemiological perspective.

The average prevalence of obesity (BMI > 30 kg/m2) among European centers participating in the WHO-MONICA study between 1983 and 1986 was about 15% in men and 22% in women Prevalence figures ranged in men from 7% in Gothenburg and 22% in Lithuania and in women from 9% to 45% in the same places. Some monitoring projects or repeated surveys suggest that the prevalence of obesity has been increasing during the past 15 years in some European countries. A closer look at data from The Netherlands suggest that average weight increase in the order of about 1 kilo can be responsible for quite dramatic increases in the prevalence of obesity. This suggest that only small changes in the daily caloric balance may be sufficient to increase the number of obese subjects in populations. In The Netherlands a decrease in energy intake and fat consumption was observed between 1987 and 1993 and smoking rates remained relatively stable. This could imply that reductions in energy expenditure are the main factors responsible for the increase in the prevalence of obesity. Since the increase in the prevalence of obesity seems to occur particularly in younger age-groups, the consequences of the increase in the prevalence of obesity only become apparent many years later. Especially chronic conditions such as arthritis or conditions related to obesity but occurring later in life such as cerebrovascular accidents, chronic heart failure or breast cancer in women. The rising prevalence of non-insulin dependent diabetes mellitus may be one of the first signs of the increasing problem of obesity in European countries.