Metabolic Changes Induced by a Very Low Carbohydrate Diet in Youth With Type 1 Diabetes

NCT ID: NCT04955691

Last Updated: 2025-10-16

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 19 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-07-29
• Study Completion Date: 2024-08-06

Brief Summary

As more adolescents with type 1 diabetes (T1D) opt to follow very low carbohydrate diets to improve glucose control, it is becoming increasingly important to study the metabolic and neurological changes that occur on these diets and how these effect patient safety. Understanding the impact of dietary changes on metabolic and neurological factors will help guide clinical advice about the overall safety and efficacy of these diets in the pediatric T1D population. This work will be the basis of future studies testing dietary interventions to improve glycemic control and ensure that these dietary interventions are safe for growing youth with T1D.

Detailed Description

The primary objective of this randomized crossover study is to determine whether a very low carbohydrate diet improves glycemic changes (measured by continuous glucose monitors) when compared to a standard carbohydrate diet in youth with type 1 diabetes.

The secondary objectives of the study are to compare metabolic changes after 2 weeks on each diet using the 2-step hyperinsulinemic euglycemic-hypoglycemic clamp and stable isotope infusions. The euglycemic portion of the clamp will allow us to determine the hepatic glucose production and adipose tissue lipolysis. Secondary objectives also include measuring the neurohormonal response to hypoglycemia after 2 weeks on each diet.

Conditions

Type1diabetes, Low Carbohydrate Diet

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

low carbohydrate diet

In this crossover study, participants will be randomized to either a low or standard carbohydrate for 2 weeks. Participants in the low carbohydrate group will limit carbohydrate intake to 15% of total daily calories.

Group Type: EXPERIMENTAL

low carbohydrate diet

Intervention Type: OTHER

Participants will engage in a diet that limits carbohydrate intake to 15% of total daily calories for 2 weeks.

standard carbohydrate diet

In this crossover study, participants will be randomized to either a low or standard carbohydrate for 2 weeks. Participants in the standard carbohydrate group will follow an ad libitum diet with standard carbohydrate intake.

Group Type: ACTIVE_COMPARATOR

standard carbohydrate diet

Intervention Type: OTHER

Participants will engage in a diet that recommends standard carbohydrate intake with respect to total daily calories for 2 weeks.

Interventions

low carbohydrate diet

Participants will engage in a diet that limits carbohydrate intake to 15% of total daily calories for 2 weeks.

Intervention Type: OTHER

standard carbohydrate diet

Participants will engage in a diet that recommends standard carbohydrate intake with respect to total daily calories for 2 weeks.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Diagnosis of type 1 diabetes for at least 1 year
• Hemoglobin A1c level < 10% within the past 2 months
• Provision of signed and dated informed consent form by the adult (if person is at least 18 years old) or parent and assent form if the participant is <18 years old.
• Stated willingness to comply with all study procedures and availability for the duration of the study
• All sexes are eligible
• Diagnosis of type 1 diabetes for at least 1 year
• Insulin pump use for at least 2 months.
• Ability to perform daily blood ketone checks, wear a continuous glucose monitor, willing to wear an activity monitor, willing to adhere to the study diets and keep a diet journal.
• For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation and for an additional 4 weeks after the end of the dietary intervention.
• For males of reproductive potential: use of condoms or other methods to ensure effective contraception with partner

Exclusion Criteria

• Current use of glucose-lowering agents other than insulin
• Unstable psychiatric disorders, including eating disorders
• Weight loss medications within the last 6 months
• Pregnancy or lactation, or planning pregnancy within the next 6 months
• BMI < 19 kg/m2 for individuals 18 years of age or older
• BMI < 5%ile for individuals under 18 years
• Weight less than 49 kg or 108 pounds
• Other medical conditions that may interfere with glucose metabolism and insulin sensitivity

• Minimum Eligible Age: 12 Years
• Maximum Eligible Age: 21 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role: collaborator

Yale University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Laura M Nally, M.D.

Role: PRINCIPAL_INVESTIGATOR

Yale University

Locations

Yale-New Haven Hospital

New Haven, Connecticut, United States

Countries

United States

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

1K23DK128560-01

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2P30DK045735-26

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2000029479

Identifier Type: -

Identifier Source: org_study_id