To investigate the socio-economic and dietary factors associated with overweight and obesity, respectively, in southern France.

Cross-sectional analysis of socio-economic, lifestyle and nutritional characteristics of a representative population sample. A questionnaire elicited information on anthropometric measurements, socio-economic factors, physical activity, tobacco use, and alcohol and food intakes. Non-parametric tests, multiple linear regression models and correspondence factorial analysis (CFA) were used to estimate the association of the various factors with overweight and obesity.

French Southwest and Mediterranean areas.

In total, 1169 subjects (578 women and 552 men), aged 30–77 years, were recruited at random.

Overweight and obesity were associated with age and education in both genders, reproductive factors in women and tobacco use in men. A few dietary factors were identified (high energy intake and low intake of carbohydrates), but all these variables explained little of the variation (18.5% in women and 14.6% in men). The CFA further investigated the association of lifestyle and nutritional factors, giving more weight to nutritional behaviour for overweight men and women. Factors for obesity differed from those for overweight by being different in men and women, possibly related to psychological behaviour, and there were fewer of them, suggesting an insufficient coverage by the usual questionnaires.

Overweight and obesity appear as two different entities. Energy imbalance induced by various lifestyle factors plays a major role in the development of overweight, whereas obesity represents a more complex entity where psychological and genetic factors that are difficult to assess may be more important. General nutritional guidelines appear more adapted to the prevention of overweight than to that of obesity, and individual counselling to the prevention of obesity.