Very low-energy ketogenic program for adults with type 1 diabetes and obesity using an automated insulin system

Applying Very Low Calorie Ketogenic Diet to the Treatment of Obesity in People With Type 1 Diabetes on Intensive Insulin Therapy Using Automated Insulin Delivery System

Not applicable Interventional Azienda Ospedaliero-Universitaria Consorziale Policlinico di Bari · NCT07185555

This will test whether a 4-week very low-energy ketogenic diet delivered with meal replacements can help adults with type 1 diabetes and obesity who use an advanced hybrid closed‑loop insulin system lose weight safely.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment14 (estimated)
Ages18 Years to 99 Years
SexAll
SponsorAzienda Ospedaliero-Universitaria Consorziale Policlinico di Bari Academic / other
Locations1 site (Bari, Italy)
Trial IDNCT07185555 on ClinicalTrials.gov

What this trial studies

This is a single-center, single-arm feasibility trial testing a 4-week Very Low‑Energy Ketogenic Therapy (600–800 kcal/day, <30 g/day carbohydrates) delivered via commercial meal replacements under close medical supervision. Participants must have type 1 diabetes for at least 12 months, BMI ≥30 kg/m², HbA1c <9%, and be using an Advanced Hybrid Closed Loop (AHCL) insulin system for at least 3 months. Primary outcome is change in body weight at 4 weeks, with secondary measures including body composition, muscle strength, glucose metrics, insulin requirements, laboratory safety parameters, and patient-reported outcomes. Safety monitoring includes frequent glucose checks, capillary ketone monitoring, and surveillance for hypoglycemia and diabetic ketoacidosis while insulin is adjusted as needed through the AHCL system.

Who should consider this trial

Good fit: Adults (≥18 years) with established type 1 diabetes (≥12 months), BMI ≥30 kg/m², HbA1c <9%, experienced in carbohydrate counting, using an AHCL system for ≥3 months, and willing to follow a prescribed meal‑replacement ketogenic program are ideal candidates.

Not a fit: People with recent diabetic ketoacidosis or severe hypoglycemia, chronic kidney disease (eGFR <60 ml/min), active eating disorders or incompatible dietary restrictions, gastroparesis, recent febrile illness, or those not using an AHCL system are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, this approach could provide a rapid, supervised weight-loss option for adults with type 1 diabetes and obesity that improves weight and metabolic markers while using closed‑loop insulin systems to lower some safety risks.

How similar studies have performed: Very‑low‑energy and ketogenic diets have proven effective for weight loss in obesity and type 2 diabetes, but evidence in type 1 diabetes is limited and safety concerns have previously constrained testing, with closed‑loop insulin systems now offering a safer context for exploration.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Age ≥ 18 years

Diagnosis of type 1 diabetes or autoimmune diabetes for ≥ 12 months

BMI ≥ 30 kg/m²

HbA1c \< 9%

Knowledge and use of carbohydrate counting

Use of an Advanced Hybrid Closed Loop (AHCL) system for ≥ 3 months and willingness to maintain it during the study

At least 1 diabetology follow-up visit in the last 12 months (including telemedicine)

Willingness to purchase meal replacements for the entire study duration

Exclusion Criteria:

Ketoacidosis, severe hypoglycemia with seizures/coma, or severe hyperglycemia requiring hospitalization in the last 6 months

Febrile illness within the last 2 weeks

Dietary restrictions or intolerances incompatible with study food supplies

Celiac disease, gastroparesis, food allergies

Intense physical exercise \>2 hours on \>3 days per week

History or risk of eating disorder, or other psychiatric disorders

Recreational drug use or excessive alcohol consumption

Chronic kidney disease (eGFR \<60 ml/min)

Gallstones

Liver failure

Heart failure (NYHA III-IV), unstable angina, cardiac arrhythmia, myocardial infarction, or stroke within the last 12 months

Respiratory failure

Severe or active infections

Planned elective surgery

Rare metabolic diseases (porphyria, CPT2 deficiency, mitochondrial fatty acid oxidation defect, pyruvate carboxylase defect)

Pregnancy (current or actively trying to conceive)

Breastfeeding

Current glucocorticoid therapy (except stable low-dose, inhaled, or replacement for adrenal insufficiency)

Other serious medical conditions that might interfere with participation or study completion in the investigator's judgment

Participant judged unable or unwilling to complete the study

Where this trial is running

Bari, Italy

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Type 1 DiabetesObesityType 1 Diabetes MellitusVery Low-Energy Ketogenic DietInsulin TherapyWeight LossContinuous Glucose MonitoringAdvanced Hybrid Closed Loop
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.