Type 1 Diabetes Research Study

A clinical trial conducted at Boston Children's Hospital currently recruiting participants with type 1 diabetes. We are studying how the carbohydrate content of an assigned diet affects blood glucose control and brain function in those with the condition.

• Consuming foods given to you by the study team for 12 weeks. These study meals will be delivered to your home by a company specializing in food delivery. You will be randomly assigned to receive one of two different diets: a standard carbohydrate diet, which follows routine dietary recommendations for diabetes, or a very low carbohydrate (ketogenic) diet.
• You will be asked to upload and share data from your diabetes devices (CGM, insulin pump) to a cloud-based software and have a weekly check-in with the study team. You will be asked to use a wrist-wearable activity monitor to quantify exercise.
• Up to five weekday in-person study visits at Boston Children’s Hospital or Beth Israel Deaconess Medical Center over the course of 12 weeks. Most visits take about one to two hours, and some involve a blood draw. On the morning of some of your in-person visits, you will be asked to arrive fasted (no eating).
• Two of the visits take longer, about four to five hours, and involve IV placements, frequent blood draws, and a glucagon injection or MRI studies of your brain during hypoglycemia (low blood sugar) response. You will receive IV insulin to drop your blood glucose level to 50 to 60 mg/dL for up to 30 minutes. One of these visits may include a ketone drink.

Learn more about this clinical trial and eligibility criteria on our study details page. See information on our study on ClinicalTrials.gov and the Boston Children’s Hospital Clinical Trial Finder.

• free home delivery of all your meals for 12 weeks
• intensive diabetes management and medical supervision
• compensation up to $1,300
• free parking or travel reimbursement for the study visits 

Males and females aged 18-40 with:

• type 1 diabetes for at least 1 year
• BMI between 18.5-35 kg/m2
• stable glycemic control (HbA1c = 6.5-9%)
• current use of a CGM and insulin pump
• attendance of at least one diabetes care visit (including virtual) in the past year

Conditions that prohibit participation:

• diabetic ketoacidosis (DKA) or hypoglycemia with seizure or coma in the past six months
• dietary restrictions or intolerances that are incompatible with planned food deliveries (e.g., celiac disease, gastroparesis, some allergies)
• following a weight loss or otherwise restrictive diet
• vigorous exercise for more than 2 hours on more than 3 days per week
• history of an eating disorder or at risk of one
• major medical illness or use of certain medications other than insulin and metformin that could interfere with metabolic or glycemic variables
• significant psychiatric illness
• smoking, use of recreational drugs, or excessive alcohol consumption
• pregnancy or breastfeeding
• anemia
• for participants who undergo an MRI: standard MRI exclusion criteria; irregular menses; use of certain psychotropic medication (except SSRI or other mild anti-depressive or anti-anxiety medication, unless these medications are safe to be held for several days to allow for the acquisition of MRI data) of psychotropic medication that cannot be safely held for MRI image acquisition

Symptoms such as fatigue, cramps, and constipation may occur when switching to a very low carbohydrate diet. Possible risks include hypoglycemia or elevated ketone levels while following the very low carbohydrate diet or from the ketone drinks. You may feel nauseous from the glucagon medication or ketone drink. There is a small chance of allergic reaction from the delivered meals or study medications (glucagon, oral ketones). You may experience slight pain or bruising from the blood draws and a feeling of claustrophobia (fear of small places) during the MRI.

Despite technological advances, glucose control remains suboptimal in people with type 1 diabetes. Diet plays an important role in diabetes management, and some foods have a bigger effect on blood glucose than others. This study will help us understand the effect of dietary carbohydrate on blood glucose control and brain function in people with type 1 diabetes, and evaluate the effects and safety of a very low carbohydrate compared to a standard diet.

Participating in research is voluntary and separate from your clinical care. You may decline participation or start the study and choose to drop out at any time. All research data are kept confidential.

More details about study visits

• After the initial screening visit, there will be an individual visit during which you will have a fasting blood draw, be randomly assigned one of the two diets, and receive diet education and a refresher on diabetes management skills. This visit should take roughly two hours.
• Each weekly visit thereafter will be an individual check-in and last about 30 minutes. Most of the check-ins will be on Zoom. We will collaboratively review your blood glucose and insulin data, and may decide to adjust your insulin regimen. At the end of the study, you will come in to Boston Children’s Hospital or Beth Israel Deaconess Medical Center in the morning after a 10-hour fast, and we will take a small sample of blood.
• During the metabolic visits to evaluate your hypoglycemia response, we will place two IV catheters, one to give medication (insulin, dextrose) and one to check your blood glucose and other labs every five to 30 minutes. We will slowly drop your blood glucose level to 50-60 mg/dL and safely keep it there. A physician will be with you at all times, and we will have IV glucose to treat you quickly if your blood glucose level drops too low or you become uncomfortable. Depending on the visit, you will receive a glucagon injection or have a brain MRI (may be with or without a ketone beverage) to evaluate brain function during hypoglycemia.

More details about research procedures

• Food will be delivered weekly to your home address (three meals and one-to-two snacks per day).
• You will be asked to eat only the foods that are provided to you by the study.
• You will be asked to maintain your current level of physical activity.
• You will be asked to complete a brief daily online questionnaire on hunger, hypoglycemic episodes, physical activity, etc.
• You will be asked to upload your diabetes devices once each week to a diabetes data management software, and have a weekly check-in with the study team.
• You will need to contact the study team to reschedule if you are unable to make your scheduled study visit.

You can also find answers to your questions on our FAQ page.