Morbid or severe obesity is a chronic pathology of multifactorial etiology that affects 4.3% of the French population. In these patients, eating disorders are frequent and must be managed as they are considered risk factors with poorer weight prognosis and lower quality of life.

Some authors have proposed that the concept of food addiction (i.e., the existence of an addiction to certain foods rich in sugar, fat and/or salt) may make it possible to identify, among obese patients, a subgroup of patients that is more homogeneous in terms of diagnosis and prognosis.

Food addiction is common in obese patients and is associated with higher levels of depression, anxiety, impulsivity, emotional eating and poorer quality of life. Nevertheless, we do not know the impact of managing this addiction on the future of these patients (food addiction, weight, comorbidities, quality of life). Telephone-based cognitive behavioral therapy intervention (Tele-CBT) is a treatment of choice for addictions, but there are inequalities in access to this treatment (distance between home and hospital, limited local resources of caregivers, constraints in patient availability) which require the therapeutic framework to be adapted to these constraints. A short Tele-CBT program has demonstrated its effectiveness in reducing bulimic hyperphagia in these patients (Cassin et al. 2016), but its effectiveness on food addiction, Body Mass Index and the evolution of metabolic complications related to obesity is still unknown. The evaluation of this program was limited to 6 weeks (American study), and we do not know if these results can also be extrapolated to France.

The main hypothesis of this study is that in patients suffering from severe or morbid obesity and with food addiction, the performance of tele-CBT (intervention group: 12 sessions for 18 weeks) will be accompanied by a significant medium-term decrease in the prevalence of food addiction compared to usual management (control group).

Morbid or severe obesity is a chronic pathology of multifactorial etiology that affects 4.3% of the French population. In these patients, eating disorders are frequent and must be managed as they are considered risk factors with poorer weight prognosis and lower quality of life.

Some authors have proposed that the concept of food addiction (i.e., the existence of an addiction to certain foods rich in sugar, fat and/or salt) may make it possible to identify, among obese patients, a subgroup of patients that is more homogeneous in terms of diagnosis and prognosis.

Food addiction is common in obese patients and is associated with higher levels of depression, anxiety, impulsivity, emotional eating and poorer quality of life. Nevertheless, we do not know the impact of managing this addiction on the future of these patients (food addiction, weight, comorbidities, quality of life). Telephone-based cognitive behavioral therapy intervention (Tele-CBT) is a treatment of choice for addictions, but there are inequalities in access to this treatment (distance between home and hospital, limited local resources of caregivers, constraints in patient availability) which require the therapeutic framework to be adapted to these constraints. A short Tele-CBT program has demonstrated its effectiveness in reducing bulimic hyperphagia in these patients (Cassin et al. 2016), but its effectiveness on food addiction, Body Mass Index and the evolution of metabolic complications related to obesity is still unknown. The evaluation of this program was limited to 6 weeks (American study), and we do not know if these results can also be extrapolated to France.

The main hypothesis of this study is that in patients suffering from severe or morbid obesity and with food addiction, the performance of tele-CBT (intervention group: 12 sessions for 18 weeks) will be accompanied by a significant medium-term decrease in the prevalence of food addiction compared to usual management (control group).

Inclusion Criteria:

• Age 18-65 years
• BMI ≥35kg/m² (morbid or severe obesity)
• First appointment to a physician specialized in nutrition
• "Food addiction diagnosis" according to the YFAS 2.0
• Affiliated to the French national health service
• Consent signed

Exclusion Criteria:

• Difficulties in understanding the self-administered questionnaires, including illiteracy
• Impossibility to participate to the CBT sessions (i.e., no phone, scheduled unavailability)
• Not eligible for CBT (i.e., cognitive disorders, hearing disorders)
• Antecedent of monogenic or oligogenic obesity (MC4R mutation)
• Severe alcohol use disorder (at least 6 out of 11 DSM-5 criteria for alcohol use disorder)
• Current medication with a significant adverse effect on eating behavior (i.e., lithium, neuroleptic/antipsychotic)
• Discrepancy between self-administered questionnaires and the clinical interview conducted prior to inclusion (for the assessment of food addiction diagnosis).
• Condition associated with important weight variations (i.e., oedema related to severe cardiac insufficiency, renal insufficiency, hepatic insufficiency with cirrhosis, exudative enteropathy)
• Participation to another psychological or pharmacological interventional study that could impact our primary or secondary outcomes
• Wearing a pace-maker or metal prosthesis
• Person under tutorship or curatorship