Is an intensive lifestyle modification programme aimed at weight reduction of effective in obese females attending a primary care setting in suburban Sri Lanka?

Blood samples will be obtained from all participants for the screening for the following: diabetes mellitus dyslipidaemia, thyroid disease. Once enrolled in the study their anthropometric measurements (height, weight, waist circumference, hip circumference) will be monitored monthly.

The study will be conducted in 2 stages.

During the first stage participants will be maintained on standard care which consists of lifestyle advice (exercise and diet) that is given to all obese patients who visit the clinic and their weight will be monitored for a period of 6 months.

The second stage includes a further 6 months where the participants are invited to participate in an exercise program which includes introduction of Cognitive-Behavioural Therapy (CBT) based lifestyle modification program. The following will be introduced: 1. Individual sessions with the principal investigator for the assessment of physical fitness and level of exercise that they can engage in. 2. Incorporating exercise in to the daily work schedule 3. Introduction to an activity diary which records the daily energy intake and expenditure (self monitoring) 4. Provision of sample diet sheets and food substitutes 5. Introduction of methods to re-channel negative thought processes to more constructive thoughts (cognitive restructuring) 6. Proactive problem solving and dealing with situations which precipitate cravings (stimulus control and adapting alternative behaviours) 7. Exercise sessions conducted once a week with 10-15 participants in a group by a qualified instructor from the physical education unit of the University of Kelaniya. All sessions will be conducted in the Faculty of Medicine, University of Kelaniya in the presence of an MBBS qualified doctor. 8. Building peer groups who can get together and organise walks in the evenings

1. Females with age between 18 to 65 years
2. Body mass index between 27.5 and 40 kg/m2
3. Residing in Ragama and receiving primary care at the Faculty of Medicine, Family Medicine Clinic

1. Unwilling to attempt weight loss
2. Significant medical co-morbidities, including uncontrolled metabolic disorders (e.g., thyroid, diabetes, renal, liver), unstable heart disease and ongoing substance abuse
3. Taking prescription medications for: diabetes, hypertension, dyslipidaemia
4. Psychiatric disorders requiring antipsychotics or multiple medications
5. Body weight change > 10 kg in the preceding 3 months
6. Pregnant, planning to become pregnant, or lactating less than six months

7. Plans to move during the study period (24 months post randomization)

   Participants achieving a BMI of 23.5 kg/m2 or becoming pregnant will be excluded.