Very Low Carbohydrate Diet as an Adjunctive Therapy for Youth Type 1 Diabetes
Condition: Type 1 Diabetes
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 1
Study type: Interventional

Summary: 
      This prospective, open-label pilot/feasibility study of 10 youth with T1D is to evaluate
      glycemic and metabolic changes taking place with a very low carbohydrate diet.
    

Detailed description: 
      First, to evaluate the feasibility of following each type of VLCD (high protein or high fat),
      participants will follow a standard carbohydrate diet for 2 weeks, followed by a 1 week
      transition to a VLCD, and then follow the a high protein VLCD for 2 weeks followed by a high
      fat VLCD for 2 weeks. The study will consist of 4 in person or virtual visits which will take
      place over ~7 weeks. All participants will be initially studied for 2 weeks while ingesting a
      standard diet recommended by the American Diabetes Association, followed by a 1-week
      transition to a VLCD, and followed by 2 weeks on each type of VLCD (high protein, high fat).
      During the first (baseline) period fasting β-hydroxybutyrate levels will be measured 2-3
      times per week. During the VLCD study periods, fasting β-hydroxybutyrate levels will be
      measured daily in the morning using a blood ketone meter; insulin doses will be collected
      using insulin pump downloads and continuous glucose monitoring (CGM) profiles will be used to
      assess glycemic excursions on each diet, as well as the time in hypo-, eu- and hyperglycemic
      ranges. The purpose of this study is to examine changes in sensor glucose levels, basal and
      bolus insulin doses, and metabolic factors following implementation of a very low
      carbohydrate diet (VLCD). Sensor-derived time glucose ranges will serve as a surrogate marker
      of hemoglobin A1c given the short duration of the study. Safety measures of the diet will
      also be assessed, including daily fasting ketone levels.

      The first hypothesis of the study is that use of a VLCD with strict monitoring of ketosis
      will reduce glycemic variability and increase time in target range, defined as 70-180 mg/dL
      by reducing the time in the hyperglycemic (>180 mg/dL) and hypoglycemic ranges (<70 mg/dL).
      Decreased carbohydrate intake will lead to less postprandial hyperglycemia. Lower insulin
      doses for meals and snacks as a result of decreased carbohydrate intake will lessen
      postprandial hypoglycemia as well.
    

Intervention name(s): Very Low Carbohydrate Diet
Intervention type(s): Behavioral
Intervention description(s): A very low carbohydrate diet (VLCD), is defined as limiting carbohydrate intake to 11% of total daily caloric intake.
Intervention model: Sequential Assignment
Intervention model description: Following enrollment, participants will follow a standard carbohydrate diet for 2 weeks. They will then undergo a 1 week transition followed by 2 weeks on a higher protein very low carbohydrate diet that is then followed by 2 weeks on a higher fat very low carbohydrate diet.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: very low carbohydrate diet