Behavioural change interventions for weight loss have been found to be effective in the short term, but their long-term effectiveness remains a question. The objective of this study was to evaluate the effectiveness of the 36 weeks F.E.A.T program combining behavioural changes of healthy eating and physical activity. A quasi-experimental study of overweight adults was conducted in Malacca. A total of 53 subjects (mean age 47.4 ± 7.2 years) completed the program in three stages. In the first stage (T1: weeks 1–12), the intervention group (n = 28) participated in the F.E.A.T program activities, while the control group (n = 25) did not receive the intervention. In the second stage (T2: weeks 13-24), the activity was supervised and monitored by the peer support group. Sustainability of activity was measured at the third stage (T3: weeks 25-36). The effectiveness of the program was measured by changes in dietary intake, physical activity score, body weight, body mass index (BMI), waist circumference (WC) and body fat percentage at T0 (pre-intervention), T1, T2 and T3. All parameters showed significant interaction effects (time*group) except for energy intake. The intervention group showed significant decreases from T0 to T3 for energy intake (-14.3%), body weight (-4.3%), BMI (-4.2%), WC (-10.5%) and body fat percentage (-3.6%). While physical activity level increased by 109.6% for the intervention group. There were no significant differences in all of these parameters among the control group. The results show the effectiveness of the F.E.A.T program on dietary status and physical activity changes during the 36-week of intervention period.