Impact of Meal Timing on Glycemic Profiles in Adolescents with Type 2 Diabetes

CANDIDATE: Alaina Vidmar is a pediatric clinical scientist specializing in treatment of adolescents with obesity

and type 2 diabetes (T2D). The proposed study will focus on investigating if time-limited eating (TLE: 8-hour

eating/16-hour fasting) in adolescents with T2D reduces glycemic excursions, delays β-cell dysfunction, and

reduces body fat mass compared to prolonged eating period (12+hours). This K23 Award will provide her with

advanced training in clinical trial design and advanced statistical methods, pediatric nutrition and body

composition measurement, and glucose monitoring technology, all of which are required for her to compete for

independent R01 funding. RESEARCH CONTEXT: Preliminary evidence, mostly in adults, has shown that TLE

reduces body weight and fat mass, improves insulin sensitivity, reduces hepatic fat accumulation, and is safe

with minimal risk when compared to prolonged eating windows and has no negative effect on daily function or

lifestyle behaviors. 1–12 Because of its simplicity, TLE may represent a more feasible approach for adolescents

than other caloric restriction regimens. Our preliminary data support TLE feasibility, acceptability, and safety in

adolescents with obesity, with and without diabetes.13–15 However, no trial to date has studied the effects of TLE

on glycemic control and body composition in adolescents with T2D. We hypothesize that TLE will reduce

glycemic excursions, improve β-cell function, and reduce body fat mass in adolescents with T2D when compared

to prolonged eating periods. One-hundred adolescents with T2D (aged 14-21 years), with a hemoglobin A1c

(HbA1c) < 9%, and on Metformin monotherapy, will be recruited. All participants will be randomized to one of

two meal-timing schedules to be followed for 12 weeks: (1) Control: >12-hour eating or (2) TLE. We will examine

the effects of TLE versus control in 3 specific aims: (1) Effects on glucose control as measured by percent time

in range (captured from continuous glucose monitoring data), Hemoglobin A1c, and β-cell function (mean change

in insulinogenic index after a mixed meal tolerance test); (2) Effects on body composition and liver fat (DEXA

and magnetic resonance imaging); and (3) Effects on sleep, physical activity, and dietary intake. CAREER

DEVELOPMENT: Dr. Vidmar has access to a rich academic research environment, one of the largest pediatric

T2D populations in the country, the support of her institution, and a stellar mentoring committee consisting of (1)

Dr. Goran, a pediatric nutritional scientist, (2) Dr. Raymond, a physician-scientist with expertise in diabetes

technology, (3) Dr. Ramon Durazo-Arvizu, a statistician, (4) Dr. Espinoza, an expert in clinical bioinformatics,

and (5) Dr. Salvy, a behavioral and clinical psychologist with expertise in TLE implementation. The two co-

primary mentors, Drs. Goran and Raymond will be responsible for guiding Dr. Vidmar in achieving the milestones

towards transition to independence. In summary, this proposal meets a critical need for finding an effective

dietary intervention for treatment of adolescents with T2D and provides Dr. Vidmar with a robust training platform,

and structured mentoring path towards an R01-level competitive application.