OBJECTIVES: To evaluate the 5-year incidence of obesity in a sample of CVD-free adults and investigate the potential effect of several sociodemographic and lifestyle habits on weight change and obesity incidence in these individuals. METHODS: Men (n 1514) and women (n 1528) (>18 years) without any clinical evidence of CVD, living in the Attica area of Greece, were enrolled in the ATTICA study from May 2001 to December 2002. The sampling was random, multistage and included information about various sociodemographic, lifestyle (diet, exercise and smoking), biochemical and clinical characteristics. In 2006, the 5-year follow-up was performed through telephone calls or personal visits. Data from the 1364 participants are analysed in the present work. RESULTS: The 5-year incidence of obesity was 21.8 % in men and 11.9 % in women. The ratio of men to women revealed that more men than women developed obesity, while more women than men became overweight during the follow-up period. It was found that men were 1.6 times more likely to develop obesity compared with women; abnormal waist circumference, smoking habits and the presence of hypercholesterolaemia increased the risk for developing obesity, irrespective of age and baseline lifestyle characteristics of the participants. In the multivariate analysis, no association was detected between adherence to a Mediterranean diet and incidence of obesity in initially normal-weight individuals. CONCLUSIONS: Obesity remains a serious health problem for the Greek population; the alarming rates of excess body weight continue to increase. Preventive measures should be urgently addressed, targeting particularly those with metabolic risk factors.