The ACT-based intervention integrates educational topics on heart healthy behaviours with mindfulness and acceptance training regarding difficult thoughts and feelings, clarification of health-related values and commitment to behave in the valued direction while contacting difficult experiences.

These programs are based on current guidelines for the long- term multi-disciplinary rehabilitation and prevention of obese patients, including Cognitive Behavioral Therapy (CBT), in a group setting, as Gold Standard.

Assigned Interventions: Behavioral: usual care (CBT)

The change in the score of CORE-OM measured in three time points, before treatment (baseline), post treatment (after one month in-patient rehabilitation program) and at 6 months Follow-Up. CORE-OM (Italian version by Palmieri et al., 2009) is a self-report measure designed for use as a baseline and outcome measure in psychological therapies and after its conclusion. It assesses the subjective experience of a person, as well as the way he or she functions in the world. It is composed by 34 items on a 5-points likert-scale from 0 (never) to 4 (always). Low scores correspond to high wellbeing. The CORE-OM provided 5 scales: wellness, symptoms, functioning, risk and total. The investigator involved in administering and interpreting the CORE-OM were blinded to treatment assignment.

The change in the score of AAQ-II measured in three time points, before treatment (baseline), post treatment (after one month in-patient rehabilitation program) and at 6 months Follow-Up.The Acceptance and Action Questionnaire (AAQ; Hayes et al., 2004) is the most widely used measure of experiential avoidance and psychological inflexibility. We used the 7-item Italian (7-points likert-scale from 0-never true to 7-always true) version of AAQ-II (Pennato, Berrocal, Bernini & Rivas, 2013) that shows adequate indexes of validity and reliability with a single-factor structure. In the case of AAQ-II higher scores indicate greater psychological flexibility.

The change in the weight, expressed in kilograms, measured in three time points, before treatment (baseline), post treatment (after one month in-patient rehabilitation program) and at 6 months Follow-Up.