Dinner Time for Obesity and Prediabetes (DTOP)

National Institute Of Diabetes And Digestive And Kidney Diseases

Investigators

Abstract

We will recruit people aged 18 to 50 years into two groups: people who are obese and have prediabetes, and people who have a normal weight and are healthy. Participants will have one overnight stay at Johns Hopkins University (JHU) and two 2-night stays at the National Institutes of Health (NIH). The NIH stay will be repeated after 3 to 4 weeks. The sleep and meal schedules will be different at each visit. Each participant will undergo circadian phenotyping with assessment of DLMO and core body temperature profile, as well as wrist actigraphy. Thereafter, participants will be crossover randomized to (1) a 24-hour metabolic chamber protocol where dinner is eaten 3 hours before DLMO (early dinner), or (2) a 24-hour metabolic chamber protocol where dinner is eaten 1 hour after DLMO (late dinner). The timing and nutritional contents of all meals, as well as sleep timing and duration, will be held constant. Oral 2H31 palmitate will be given with each dinner condition to quantify dietary fat oxidation. The 2 dinner conditions will occur in random order, with a 3- to 4-week washout period. The study will recruit a total of 32 participants in 2 cohorts: 16 individuals who are normal-weight and healthy and 16 individuals with obesity and prediabetes. Each cohort will comprise 8 men and 8 women. Randomization will be stratified by cohort and by sex.