Effect of Advanced Hybrid Closed Loop System, MiniMed 780G in Newly Diagnosed Children and Adolescents With Type 1 Diabetes on Glycemic Control and Patient Reported Outcomes Compared to Standard Insulin Therapy Historical Data (AHCL in New Onset T1D Children Study)

Inclusion Criteria: 1. Clinical diagnosis of type 1 diabetes (WHO criteria). Diagnosis of type 1 diabetes is based on international criteria and the investigator's judgment; C peptide level and antibody determinations are not required. 2. Age range 7 to 17 years. 3. Literate in Greek or English. 4. Willing to wear study devices. 5. Willing to follow study-specific instructions. 6. Total daily insulin dose greater than 8.0 units over 1 week period 7. Willing and able (access to internet from home) to download information into the Medtronic CareLink software 8. Clinically eligible to start the AHCL system Exclusion Criteria: * Type 2 diabetes mellitus or MODY diabetes * Any untreated comorbidities of type 1 diabetes * Medication affecting metabolic control or interfering in the interpretation of HbA1c * Pregnancy * Untreated diabetes retinopathy, or other causes that in the investigator's opinion, precludes the individual from participating in the trial. * Known or suspected allergy to insulin. * Regular use of acetaminophen. * Lack of reliable telephone facility for contact. * Living alone. * Severe visual or hearing impairment. * Medically documented allergy to the adhesive of plasters or unable to tolerate tape adhesive around sensor placement. * Serious skin lesions at areas of the body used for insertion of the glucose sensor. * Illicit drugs abuse. * Alcohol abuse. * Sickle cell disease, haemoglobinopathy, receiving red blood cell transfusion or erythropoietin within 3 months prior to time of enrollment. * Eating disorder including anorexia/bulimia. * Milk protein allergy.