Eligibility: obese patients attending our center. Exclusion criteria: previous dietary or anti-obesity drugs treatments, previous bariatric surgery, eating disorders, desire for short-term bariatric surgery, active neoplasia, end stage kidney or liver disease, food allergies or celiac disease.
Sample Size: a total of 260 patients (130 patients in each group) are needed for α=0.05 and 1-ß=0.8, to reach a difference of a 5% in weight loss between both groups, with a maximum of a 30% dropouts.
Intervention: structured health education program of Mediterranean diet and lifestyle changes with cooking lessons in monthly sessions, with the aid of phone and email contacts during an induction phase of 6 months, followed by an extension period of 18 months.
Control: same strategy without the cooking lessons. Primary outcome: weight loss in % Secondary outcomes: reversal in obesity associated comorbidities and quality of life.
