NCT06503809 · Washington University School of Medicine
Efficacy and Safety of a Ketogenic Diet in Type 1 Diabetes
What this study is about
Despite strong evidence that tight control of blood sugar reduces the risk of diabetes complications, most people with type 1 diabetes do not achieve recommended blood sugar targets. This randomly assigned controlled trial will test whether a very-low- carbohydrate ketogenic diet can effectively and safely improve blood sugar control in adults with type 1 diabetes.
View original scientific description
Despite strong evidence that tight control of blood sugar reduces the risk of diabetes complications, most people with type 1 diabetes do not achieve recommended blood sugar targets. This randomized controlled trial will test whether a very-low- carbohydrate ketogenic diet can effectively and safely improve blood sugar control in adults with type 1 diabetes.
Interventions
BEHAVIORAL
Ketogenic Diet
Participants will consume a very-low-carbohydrate ketogenic diet for 12 weeks.
BEHAVIORAL
Standard Diet
Participants will consume an American Diabetes Association-recommended standard diet for 12 weeks.
Primary outcome measures
Change in continuous glucose monitor (CGM) time-in-range
Time frame: Before and immediately after the dietary intervention
Interstitial glucose percent time in range assessed by using a continuous glucose monitor
Change in skeletal muscle insulin sensitivity
Time frame: Before and immediately after the dietary intervention
Insulin sensitivity will be determined by the hyperinsulinemic-euglycemic clamp procedure
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age ≥18 and ≤65 years
- T1D diagnosed \>1 year prior to screening
- HbA1c 7.0%-9.0%
- Stable insulin delivery method for the past 30 days
- Ability to read all device instructions and insulin pump settings
- eGFR ≥60 mL/min/1.73 m2
- Use of an insulin pump or insulin delivery by multiple daily injections
- Use of personal CGM for at least 12 weeks and willing to change to Dexcom CGM for the duration of the study, if using a different sensor, to reduce variability in glucose values associated with different CGM products
- Use of cellular phone with data capability for wireless connectivity to the CGM system.
Exclusion criteria
- Body mass index \<20.0 or \>34.9 kg/m2
- Severe gastroparesis or history of bariatric surgery
- Diabetes-related hospitalization (including for diabetic ketoacidosis or severe hypoglycemia) within 12 months of screening
- Poorly controlled hypertension (SBP ≥160 mmHg or DBP ≥100 mmHg)
- Taking diabetes medications, other than insulin (particularly SGLT2 inhibitors, which are associated with an increased risk of euglycemic DKA)
- Structured exercise \>210 minutes per week
- Pregnant, lactating, not using effective birth control if premenopausal, or planning to become pregnant within the 6-month study period
- Unstable weight (\>4% change in the last 2 months)
- Significant organ system dysfunction (e.g., severe pulmonary, renal, hepatic, or cardiovascular disease)
- Anemia (Hgb \<10 g/dL)
- Major psychiatric illness
- Active tobacco use (\>8 cigarettes/day) or illegal drug use
- Regular alcohol consumption (\>10 standard drinks per week)
- Use of medications known to affect the study outcome measures or increase the risk of study procedures that cannot be temporarily discontinued for this study
- Familial hypercholesterolemia
- Active eating disorder
- Dietary restrictions incompatible with a very-low-carbohydrate KD, vegan diet, vegetarian diet, severe lactose intolerance, severe aversion/sensitivity to eggs, fish, nuts, wheat, or soy, and any anaphylactic food allergy
- Already consuming a low-carbohydrate (\<130 g/day) diet
- Persons who are not able to grant voluntary informed consent
- Persons who are unable or unwilling to follow the study protocol or who, for any reason, the research team considers an inappropriate candidate for the study.
Where
- St Louis, Missouri
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 19, 2026 · Source of record for eligibility and locations