Determinants of geographical variations in body mass index (BMI) and obesity in Spain.
OBJECTIVE
To identify the factors associated with geographic variations in Body Mass Index (BMI) and obesity in Spain.


METHODS
Cross-sectional, ecological analysis using data on illiteracy rate (per 1000 population), energy intake (kcal/person/d), sedentary population (%), smoking population (%), alcohol consumption (g/person/d), and percentage of population aged 65 y or over, for Spain's 50 provinces.


METHODS
Non-institutionalized population aged 16y or over.


METHODS
Median BMI and percentage of population with obesity, defined as BMI > 30 kg/m2.


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 coefficient (beta = 0.01; P = 0.005) and obesity (beta = 0.05; P = 0.013). Sedentary lifestyle showed a statistically significant relationship with BMI (beta = 0.01; P = 0.03), but not with obesity (beta = 0.03; P = 0.581). Energy intake exhibited a relationship with BMI (beta < 0.01 P = 0.03) that lost statistical significance when adjusted for age.


CONCLUSIONS
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.
Gutiérrez-Fisac
J L
JL
Department of Preventive Medicine and Public Health, Autonomous University of Madrid, Spain.
Rodríguez Artalejo
F
F
Guallar-Castillon
P
P
Banegas Banegas
J R
JR
del Rey Calero
J
J
D000428:Alcohol Drinking; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004522:Educational Status; D002149:Energy Intake; D015444:Exercise; D006801:Humans; D008019:Life Style; D009765:Obesity / Q000453:epidemiology*; D011897:Random Allocation; D012907:Smoking; D012923:Social Class; D013030:Spain / Q000453:epidemiology