The investigators hadn't got funding to support the study

Clinical trial comparing two health education programs for obese patients in order to achieve a substantial and beneficial weight loss, using mediterranean diet. Patients will be allocated to two groups, one will receive education in diet and lifestyle, and the other one the same plus cooking lessons. The intervention period is for 6 months with monthly visits and phone and email contacts in between. An extension observation period of two years is also planned with 6 months contacts in our clinic, also with phone and email contact available.

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.

Inclusion Criteria:

• Obese patients attending our center

Exclusion Criteria:

• Previous dietary or pharmacologic treatment for obesity, previous bariatric surgery, desired bariatric surgery in the short-term, eating disorders, end-stage kidney or liver disease, active neoplasia, food allergies, celiac disease.