Obesity and association with area of residence, gender and socio-economic factors in Algerian and Tunisian adults.

Introduction: The epidemiological transition has resulted in a major increase in the prevalence of obesity in North Africa. This study investigated differences in obesity and its association with area of residence, gender and socio-economic position among adults in Algeria and Tunisia, two countries with socio-economic and socio-cultural similarities.

Methods: Cross-sectional studies used stratified, three-level, clustered samples of 35-70 year old adults in Algeria, (women n = 2741, men n = 2004) and Tunisia (women n = 2964, men n = 2379). Thinness was defined as Body Mass Index (BMI) = weight/height <18.5 kg/m(2), obesity as BMI ≥30, and abdominal obesity as waist circumference/height ≥0.6. Associations with area of residence, gender, age, education, profession and household welfare were assessed.

Results: Prevalence of thinness was very low except among men in Algeria (7.3% C.I.[5.9-8.7]). Prevalence of obesity among women was high in Algeria (30.1% C.I.[27.8-32.4]) and Tunisia (37.0% C.I.[34.4-39.6]). It was less so among men (9.1% C.I.[7.1-11.0] and 13.3% C.I.[11.2-15.4]).The results were similar for abdominal obesity. In both countries women were much more obesity-prone than men: the women versus men obesity Odds-Ratio was 4.3 C.I.[3.4-5.5] in Algeria and 3.8 C.I.[3.1-4.7] in Tunisia. Obesity was more prevalent in urban versus rural areas in Tunisia, but not in Algeria (e.g. for women, urban versus rural Odds-Ratio was 2.4 C.I.[1.9-3.1] in Tunisia and only 1.2 C.I.[1.0-5.5] in Algeria). Obesity increased with household welfare, but more markedly in Tunisia, especially among women. Nevertheless, in both countries, even in the lowest quintile of welfare, a fifth of the women were obese.

Conclusion: The prevention of obesity, especially in women, is a public health issue in both countries, but there were differences in the patterning of obesity according to area of residence and socio-economic position. These specificities must be taken into account in the management of obesity inequalities.