This is a two-year project. In the first year, we estimated the prevalence of obesity and metabolic syndrome and explored their relationship with dietary intake and exercise status using the cross-sectional framework in subjects aged 40 years and over from Taichung Community Health Study. Then, we conducted a randomized controlled trial to evaluate the effects of three types of weight control educational intervention programs. Obese subjects were randomly allocated into "individualized health education group", "fellowship health education group" and "mail-delivered health education group". The sample size for these three groups was 79, 81, 80, respectively. All subjects received one of three 6-month interventions and were followed up for 1 year and were assessed at 6-month interval.