Sociodemographic and nutritional determinants of obesity in Belgium.

OBJECTIVE: To examine associations between sociodemographic, dietary factors and physical activity and the prevalence of obesity in the Belgian general population. DESIGN: Base-line data from the Belgian Interuniversity Research on Nutrition and Health (BIRNH) study (1979-1984). SUBJECTS: A total of 5837 men and 5243 women aged 25-74y were included in the analysis. The sample was considered representative of the Belgian population. MEASUREMENTS: Using the body mass index (BMI) as the criterion, obesity was defined as a BMI> or =30 kg/m2. Nutritional data were assessed by a 24 h food record. Physical activity level (PAL) was calculated by dividing total caloric intake by an estimation of basal metabolic rate (BMR, predicted from gender, weight and age). Age-adjusted odds ratios (OR) of the prevalence of obesity were estimated by multilogistic regression analysis. RESULTS: Prevalence of obesity was 12.1% in men and 18.4% in women. In both sexes, prevalence of obesity increased gradually in each 10-year age category (P<0.0001) and steeply decreased with level of education. Comparing lowest (Q1) to highest quartile (Q4), after adjustment for age, prevalence of obesity decreased with total carbohydrate intake, as well as total sugar intake in both sexes, and increased with total fat intake only in men. Obesity increased with a high fat to sugar ratio (men: OR(Q4/Q1) = 1.56; confidence interval (CI): 1.25-1.93; women: OR(Q4/Q1) = 1.45; CI: 1.17-1.80). PAL was inversely and very strongly associated with obesity (men: OR(Q4/Q1) = 0.20; CI: 0.15-0.26; women: OR(Q4/Q1) = 0.18; CI: 0.14-0.23). The same associations were observed with the mean BMI. CONCLUSION: This study indicates that prevalence of obesity is particularly high in Belgium. Low level of education and reduced physical activity, increased fat intake and especially elevated fat to sugar ratio appear to be powerful determinants of obesity in this Belgian population.

Trends in the prevalence of obesity among Belgian men at work, 1977-1992.

OBJECTIVE: To assess trends in average body mass index (BMI) and the prevalence of obesity between 1977 and 1992, in middle-aged Belgian men at work. SUBJECTS: A subsample of men at work, aged 40-54 y extracted from the base-line data from four independent prospective studies, each representing a period (Physical Fitness Study (1977-1978), Belgian Interuniversity Research on Nutrition and Health (BIRNH) (1979-1984), Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases (MONICA) (1986-1991) and ORCA (1992-1993)). DESIGN: Linear regression of the average body mass index (kg/m2) and logistic regression of the prevalence of obesity (BMI > or = 30kg/m2). Independent variables taken into account in multivariate analysis were: age, educational level, marital status and region. RESULTS: In this subsample of Belgian men at work, aged 40-54 y, prevalence of obesity increased from 9.2% in 1977-1978 to 14.5% in 1992-1993. This rise was present in each five-year age group, in both regions and in all educational groups, but strongest in the lowest educated. After adjustment for sociodemographic covariables, it was estimated that with regard to 1977-1978, the proportion of men with a BMI > or = 30 kg/m2 doubled over the 15-year period (odds ratio OR (95% confidence intervals, 95% CI)): 1.98 (1.40; 2.80). CONCLUSION: Keeping in mind that the trends have been calculated from data from four different studies, presenting some shortcomings, prevalence of obesity has increased between 1977-1992 in men aged 40-54 y at work. This rise is particularly pronounced in the lower educated groups.

How far is the Belgian population from the recommended nutritional goals and ideal serum cholesterol? Belgian Interuniversity Research on Nutrition and Health Study Group.

In a national Belgian nutritional study (the B.I.R.N.H. Study), the authors review how far the Belgian population is from the recommended nutritional goals and ideal serum cholesterol. They also make comparisons between genders and look at differences according to the linguistic background (French- or Dutch-speaking subjects). Only a small percentage of the Belgian population reach the nutritional goals for total fat intake in males (8.4%) and females (7%), saturated fat intake (7.0% and 6.2%, respectively), and P/S ratio (13.5% and 12.4%, respectively). The percentages reaching nutritional goals are somewhat higher for polyunsaturated fat intake (27.9% and 28.6%, respectively) and dietary cholesterol (39.4% and 54.6%, respectively). A total of 29.9% of the male population, and 32.7% of the female population are at 'high risk' of CHD according to their serum cholesterol levels. In general the results are better for the Dutch-speaking population than for their French-speaking counterparts. In conclusion, despite modifications in eating patterns and a decrease in CHD mortality in Belgium during the 1970s, a very high percentage of males and females are still far from the recommended nutritional goals and ideal serum cholesterol levels.

Physical fitness does not reflect physical activity patterns in middle-aged workers.

Questionnaires and a sub-maximal exercise test were used to assess occupational and leisure time physical activity as well as physical fitness in a standardized prospective study in 2,565 Belgian and Slovakian middle-aged healthy workers. Less than 5% of the subjects engaged in strenuous work requiring an energy expenditure above 31.5 kJ.min-1. One-third of the Belgians and 50% of the Slovakians reported no heavy leisure time activity during the preceding 12 months. Physical fitness, defined as the workload at heart rate 150 beats.min-1 (standardized for body weight), was significantly higher in Slovakians as compared to Belgians (1.52 +/- 0.28 W.kg-1 and 1.48 +/- 0.28 W.kg-1; P less than 0.001). Occupational physical activity in Belgians and heavy leisure time activity in Slovakians were independently related to fitness levels. However, each activity score explained less than 1% of the variance of physical fitness. We conclude that in these mainly sedentary, middle-aged subjects, fitness levels are independent from the usual physical activity patterns.

Ischaemic heart disease in middle-aged men. Prevalence comparisons in Europe.

The authors report the results of a collaborative study of the prevalence of ischaemic heart disease in 6 samples of middle-aged male clerical workers, drawn from 5 European countries and covering in all 4522 subjects. Detailed standardization of data-collection methods and of coding, analysis and tabulation was undertaken.Estimated prevalence rates for angina and history of possible infarction, based on the use of a standard questionnaire, showed significant variation between samples, but the validity of international comparisons of symptoms remains unproven. Prevalence rates for ischaemic-type ECG findings were high everywhere, and mostly showed no significant variation between the groups studied. Central coding of ECG findings proved essential to the making of unbiased comparisons. Neither the prevalence rates for symptoms nor those for ECG findings in these samples were recognizably correlated with the corresponding national mortality rates for ischaemic heart disease.Several possible risk factors were studied, but the only one found to be consistently associated with ischaemic heart disease was a raised blood pressure. Cigarette smoking was strongly associated with bronchitic symptoms and dyspnoea, but an association with heart disease was not demonstrated.