In order to explore the cognitive treatment of patients with early onset anorexia nervosa (AM) in front of images of silhouettes and food, we will use the eye-tracking method. While we hypothesize a judgment disorder in these patients, the exploration of implicit cognitive treatment without desirability bias is essential. Eye-tracking is a method of recording the eye path that provides qualitative and quantitative information on the visual exploration of subjects. The visual pathway depends on how the subject's attention is directed to a given stimulus, but also on certain cognitive traits (e.g., excessive attention to details) or symptoms (e.g., avoidance of caloric food images or attraction to thin images). It is therefore a non-invasive exploration tool, which provides information on how patients look at food images and silhouettes. This project will describe the cognitive treatment of dietary stimuli and body image in young patients with early onset AM. It could identify a biomarker of AM in the pediatric population and improve the diagnosis of the disease. A better diagnosis of AM in patients under 15 years of age is essential and will improve medical care and develop personalized medicine.

Monocentric, prospective cohort, case-control type study. The population concerned is composed of patients with early onset anorexia nervosa (AM) and control subjects (two groups).

The objectives of this study are to:

Describe the cognitive treatment of early-onset AM patients with specific stimuli of the disorder (eating and body images) compared to age- and sex-matched control subjects:

• children controls not achieved with normal body mass index(BMI);
• children with unbalanced insulin-dependent type 1 diabetes, therefore subject to a strict diet that requires good nutritional knowledge and no weight judgment disorders.

Describe the links between cognitive treatment and clinical phenotype in patients with early onset AM, in particular severity of eating behaviour trouble symptomatology (TCA), psychiatric and somatic comorbidities, neuropsychological profile.

30 patients with early-onset AM. Two groups of control subjects (matched for age and gender): 30 subjects from the general population with a normal Body Mass Index (BMI) and 30 subjects with chronic somatic pathology (type 1 diabetes) without weight variation (good knowledge of dietary caloric values without impaired judgment about the caloric value of foods and representation of the body image of self and others) A total of 90 participantsPatients and controls without eating disorders will be recruited at Robert Debré Hospital, after signature of the authorization by the holder(s) of parental authority present at the time of hospitalization All patients treated in the department benefit from extensive phenotypic exploration, carried out in routine care.

For controls, phenotypic exploration will require a half-day evaluation.

Inclusion Criteria:

Patients with anorexia nervosa.

• Age 8 to 14 years,
• Early AM diagnosis (AM DSM-5 criteria, and presence of primary amenorrhea at diagnosis for girls),
• Follow-up in the Child Psychiatry Department of the Robert Debré Hospital,
• Affiliation to a social security system,
• Authorization of the holder(s) of parental authority and acceptance of the child to participate in this research.

Witnesses from the general population:

• Age 8 to 14 years,
• Normal Height-weight development defined by: Weight, Height, BMI between 10° and 90° percentile for age and sex, without changing the growth curve.
• Authorization of the holder(s) of parental authority and acceptance of the child to participate in this research

Witnesses with type 1 diabetes:

• Age 8 to 14 years,
• Type 1 diabetes for more than a year,
• Follow-up in the endocrinology department of the Robert Debré Hospital,
• Normal height-weight development defined by: Weight, Height, BMI between 10° and 90° percentile for age and sex, without changing the growth curve.
• No clear imbalance with HbA1c <8.5%.
• Authorization of the holder(s) of parental authority and acceptance of the child to participate in this research

Exclusion Criteria:

• Patients with AM.
• Existence of an intellectual deficit (IQ <70). The patient will not be able to have a new IQ test within one year of inclusion.
• Other Axis I disorder (Kiddie SAS)
• Existence of a severe neurosensory disorder
• Existence of a neurological disorder
• other eating disorders(DSM-5)
• Diabetes type 1

Witnesses :

• Any Axis I psychiatric disorder
• Existence of an intellectual deficit
• Existence of a severe neurosensory disorder
• Existence of a neurological disorder
• Long-term drug treatment (other than insulin for controls with type 1 diabetes)
• Type 1 diabetes (for controls in the general population)

Psychometric test taken in the year before inclusion