DOI: 10.2337/db23-114-lb ISSN: 0012-1797

114-LB: Early Time-Restricted Feeding Reduces Time in Elevated Glucose Range in Adults With Prediabetes

  • Endocrinology, Diabetes and Metabolism
  • Internal Medicine

Objective: Early time-restricted feeding (eTRF) is an intermittent fasting strategy restricting caloric intake to the first 6-8 hours of the day. While previous studies have shown that eTRF improves glycemia, it is unclear if the effect is due to associated weight loss or metabolic benefits of the feeding strategy itself. In this study, we evaluated the weight-independent effects of eTRF on glycemia using multiple CGM-based time in range (TIR) metrics.

Methods: We conducted a randomized 7-day isocaloric crossover supervised feeding study comparing eTRF (80% of calories consumed between 8am-1pm) to a usual feeding pattern (UFP, 50% of calories consumed after 4pm) among participants with prediabetes and BMI > 28 kg/m2 in a metabolic ward. Participants were randomized 1:1 to eTRF or UFP for days 1-7, then crossed over to the other arm on days 8-14. Food intake was tailored to meet weight stable caloric needs. Participants also wore blinded Abbott Freestyle Libre CGMs throughout the study period. We evaluated time spent below 70 mg/dL (TBR<70), in 70-140 mg/dL (TIR70-140), and in 140-180 mg/dL (TIR140-180) glucose range per arm. Further, we compared TIR140-180 between arms stratified by time of day: Daytime and Overnight (6am-12am and 12am-6am CGM readings, respectively) using linear mixed effect regression adjusting for type and order of intervention.

Results: We analyzed data from 10 participants (age 58 (10) years, 50% female, 80% Black, BMI: 37.3 (5.4) kg/m2, HbA1c: 5.8 (0.1)%). Weight change over the study period was not significant (p=0.08). Compared to UFP, eTRF was associated with a decrease in TIR140-180 overall (3.3%, p=0.01) and during Daytime (4.3%, p=0.02) but not Overnight (0.4%, p=0.73). We observed no significant differences in TBR<70 (p=0.28) and TIR70-140 (p=0.88) between arms.

Conclusion: eTRF may improve glucose control in adults with prediabetes and high BMI by reducing daytime excursions into the elevated 140-180 mg/dL range.


S. Barua: None. J. Bruno: None. S. Nasserifar: None. S. M. Vanegas: None. C. Popp: None. J. M. Walker: None. J. O. Aleman: Advisory Panel; Intellihealth, Consultant; Novo Nordisk, Employee; Veterans Administration, Research Support; NIH - National Institutes of Health, Veterans Administration.


Shapiro-Silverberg Foundation; The Rockefeller University; Doris Duke Charitable Foundation; American Heart Association (17-SFRN33490004); National Institutes of Health (K08DK117064); National Heart, Lung, and Blood Institute (5T32HL098129-12)

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