Determinants of geographical variations in body mass index (BMI) and obesity in Spain

Abstract

OBJECTIVE: To identify the factors associated with geographic variations in Body Mass Index (BMI) and obesity in Spain. DESIGN: Cross-sectional, ecological analysis using data on illiteracy rate (per 1000 population), energy intake (kcala apersona ad), sedentary population (%), smoking population (%), alcohol consumption (gapersonad), and percentage of population aged 65 y or over, for Spain's 50 provinces. SUBJECTS: Non-institutionalized population aged 16 y or over. MEASUREMENTS: Median BMI and percentage of population with obesity, de®ned as BMI b 30 kgam 2 . RESULTS: There was a clear geographical pattern, with some areas in the south and north-west of the country registering the highest BMI and prevalence of obesity and a north ± south pattern on illiteracy per 1000 population. Multivariate regression analysis showed that illiteracy, sedentary lifestyle and energy intake explain 35% and 14% of the variation in BMI and obesity, respectively. Illiteracy proved to be the variable most associated with both BMI (regression coef®cient (b b 0.01; P 0.005) and obesity (b b 0.05; P 0.013). Sedentary lifestyle showed a statistically signi®cant relationship with BMI (b b 0.01; P 0.03), but not with obesity (b b 0.03; P 0.581). Energy intake exhibited a relationship with BMI (b b`0.01 P 0.03) that lost statistical signi®cance when adjusted for age. CONCLUSION: Geographical variations in BMI in Spain are partly explained by illiteracy, sedentary lifestyle and, to a lesser extent, energy intake, whereas regional variations in obesity are related only to the educational level of the population.

Increasing prevalence of overweight and obesity among Spanish adults, 1987–1997

“…35 In Spain, however, total energy intake has not been shown to have any effect on regional differences in the prevalence of obesity in a recent ecological study. 16 These data, together with other evidence available at the individual level, make one doubt the in¯uence of energy intake on obesity at the population level, although recent studies that use more precise methods than self reports to measure energy consumption show a clear association between energy intake and weight. For this reason it has been suggested that the inconsistency of this association in epidemiological studies is related to the validity of the instruments that measure the consumption of food in the population since these instruments have been shown to underestimate intake, especially in persons with greater relative weight.…”

“…14,15 Likewise, regional differences in body mass index (BMI) and in the prevalence of obesity have been shown in Spain. 16 Some of these variations suggest that there is a potential for the reduction of the magnitude of the problem through public health intervention programs directed both to the general population and to the groups most affected.…”

Decomposing cross-country differences in levels of obesity and overweight: Does the social environment matter?

“…However, the factors that contribute to creating this gap remain unclear. Finally, we have identified two studies that, in a similar vein to ours, examine within-country differences in obesity: between two regions in Denmark (Halkjaer and Sørensen, 2004) and across Spanish regions (Gutierrez-Fisac et al, 1999). The evidence drawn from these studies suggests that differences are mainly attributable to educational level and intelligence test scores.…”

Psychosocial and Demographic Determinants of Regional Differences in the Prevalence of Obesity

“…The role of diet and physical activity in regional differences in the prevalence of obesity is not convincing (Reeder et al, 1997;Gutíerrez-Fisac et al, 1999). Comstock and co-workers found that obese subjects were less likely to move away from a defined area than lean subjects (Comstock et al, 1966), which may contribute to such regional differences.…”