Eating disorders (EDs), as classified by the American Psychiatric Association's DSM-5, have an estimated lifetime prevalence of 0.6% in the Caucasian adult population, with a male-to-female ratio of 1:8, and begin in 84% to 87% of cases between the ages of 15 and 25.

Anorexia nervosa (AN) is an eating disorder that represents a significant public health concern due to its impact on long-term morbidity and mortality. The incidence of AN is steadily increasing in many countries, particularly in France, with a prevalence of 2-3% among adolescents and young adults. A 10-year mortality rate of 5-10% has been reported, making AN the psychiatric disorder with the highest mortality rate. This predominantly female disorder (female-to-female ratio of 1:9) is defined by the persistent association of disordered eating behavior, distorted body image, and obsessions with weight and food, with detrimental health consequences. Anorexia nervosa (AN) exposes patients to numerous somatic and neuropsychiatric complications, which are poor prognostic factors. Its etiopathogenesis is multifactorial and involves environmental, psychological, genetic, and sociocultural factors. Bulimia nervosa (BN) is also associated with an intense fear of gaining weight. There is a disturbance of body image characterized by profound dissatisfaction with weight and physical appearance. BN is characterized by binge-eating episodes (consuming a large amount of food in a short period of time, associated with a feeling of loss of control) followed by inappropriate compensatory behaviors such as self-induced vomiting, misuse of laxatives, diuretics, or other medications; fasting; and excessive exercise. Individuals with bulimia nervosa generally have a subnormal body mass index (BMI), making diagnosis more difficult.

Type 1 diabetes is an autoimmune disease characterized by the destruction of the beta cells of the pancreatic islets of Langerhans, leading to a deficiency in insulin secretion. Generally, the diagnosis is made in childhood or adolescence, but late-diagnosed forms exist, forming an entity called latent autoimmune diabetes in adults (LADA), also known as type 1 diabetes. Diagnosis is made by measuring antibodies specific to type 1 diabetes: anti-GAD and anti-IA2 antibodies as the first-line tests, and anti-ZnT8 antibodies as a second-line test. Drug treatment primarily relies on continuous insulin administration via multiple daily injections or an insulin pump. Nutritional management is a cornerstone of treatment, playing a crucial role in glycemic control and the prevention of metabolic complications.

"Diabulimia" is a recent term describing a specific eating disorder in patients with type 1 diabetes. It is characterized by a voluntary restriction of insulin administration for the purpose of weight loss, at the expense of optimal glycemic control. This condition involves several complex factors (such as insulin injection, capillary blood glucose, emotions, and body image) that link diabetes management to the patient's mental health.

"Diabulimia" is not yet recognized as a distinct medical entity, lacks precise diagnostic criteria, and is difficult to detect. However, the serious consequences it entails, such as diabetic ketoacidosis in the short term and the chronic complications of hyperglycemia in the long term, make its screening essential.

Technological advances in the treatment of type 1 diabetes have been significant in recent years and have considerably improved the management of the disease.

Continuous glucose monitoring has radically changed the management of type 1 diabetes by empowering patients to self-manage and adjust their insulin therapy. Glucose monitoring methods have evolved considerably over the last few decades: from urine tests before the 1980s, to capillary blood glucose self-monitoring with a portable blood glucose meter introduced in 1978, to continuous glucose monitoring (CGM) methods that emerged in 1999.

Recently, CGMs have replaced capillary blood glucose meters. CGMs include sensors and transmitters that send blood glucose readings to a receiving system such as a meter, smartphone, or smartwatch, and potentially to a cloud service.

Currently in France, all diabetic patients on multi-injection or continuous insulin pump administration are eligible for reimbursement of a continuous glucose monitoring system allowing the measurement of interstitial glucose by wearing an interstitial glucose sensor. This study aims to evaluate blood glucose readings collected by two devices:

• Abbott FreeStyle Libre (FSL) is a flash interstitial glucose monitoring system where glucose is continuously monitored via intermittent scanning (ISGS). It is a standalone interstitial glucose sensor that collects glucose data by scanning the sensor.
• Dexcom is a real-time continuous glucose monitoring (RTGS) system. The reader provides a blood glucose reading every 5 minutes, along with a trend arrow and data collection over several hours (up to 24 hours).

These continuous glucose monitoring (CGM) methods allow blood glucose readings to be transmitted to an online platform that healthcare professionals can access. They can then analyze these readings remotely. This data analysis is assisted by algorithms that identify the time spent within, above, or below the target blood glucose level. Following the assessment by the healthcare professional, the patient can be contacted directly via the platform's instant messaging service.

In recent years, a link has been observed between type 1 diabetes (T1D) and eating disorders (EDs). Indeed, patients with T1D are at higher risk of developing an ED than the general population. This is partly explained by the fact that particular attention is paid to the dietary and nutritional management of T1D patients from the moment of their diabetes diagnosis, in order to allow for better glycemic control. Eating disorders in patients with type 1 diabetes (T1D) can lead to potentially serious complications. In the short term, they increase the likelihood of diabetic ketoacidosis resulting from hyperglycemia not corrected by adequate insulin administration. Hospitalization rates and length of stay are also significantly higher in patients with both T1D and an eating disorder. In the long term, they can lead to a higher prevalence of microvascular complications such as diabetic retinopathy (with a 2.5-fold increased risk), microalbuminuria, and diabetic neuropathy. Higher mortality has also been demonstrated in these patients: a mortality rate of 4.06% for patients with T1D, 8.86% for patients with anorexia nervosa, and 14.5% for patients with both conditions.

Few studies have investigated the association between T1D and eating disorders. These studies are older, have small sample sizes, and focus on only one type of eating disorder. Within the framework of this project, the SCOFF questionnaire will be used to screen for restrictive (anorexia nervosa) and compulsive (bulimia) eating disorders. Glycemic control will be assessed through the analysis of CGM data. No study has used this innovative tool to evaluate the impact of eating disorders on type 1 diabetes.

The aim is also to change healthcare professionals' approach to eating disorders by screening for them regularly and early to prevent chronicity and short- and medium-term complications. These results could contribute to establishing specific recommendations regarding the screening for eating disorders in the management of patients with type 1 diabetes, and for appropriate multidisciplinary care.

Inclusion Criteria:

1. Female patients
2. Patients aged 18 to 40 years
3. Patients diagnosed with type 1 diabetes (positive for anti-GAD, anti-IA2, and anti-ZnT8 antibodies)
4. Patients on insulin therapy alone (basal-bolus regimen or insulin pump)
5. Patients using a continuous glucose monitoring device such as an FSL or DEXCOM
6. Patients followed in the clinical nutrition and/or diabetology department of the Rouen University Hospital and the Le Havre Hospital
7. Social security coverage
8. Patients who have agreed to participate in the study

Exclusion Criteria:

1. Patients taking antidiabetic medication other than insulin therapy alone
2. Patients with limited understanding of spoken or written French
3. Individuals deprived of their liberty by an administrative or judicial decision, or individuals subject to legal protection measures for adults
4. Individuals under guardianship, conservatorship, or other protective supervision
5. Pregnant or breastfeeding women

type 1 diabetic patients