Abstract

Background Time-restricted eating (TRE) shows promise for metabolic health, but its effectiveness in glucose management among individuals with type 2 diabetes, and its role in modulating glucose responses to dietary intake remain poorly understood.

Objective We aimed to identify temporal associations of TRE and dietary intake with 24-hour glucose dynamics. We further examined the interactions between eating windows and carbohydrate intake.

Methods Clinical information, dietary records, and continuous glucose monitoring data from 90 Chinese adults with type 2 diabetes were analyzed. Two digital biomarkers were developed to characterize duration and regularity of eating patterns: a binary indicator for eating windows <10 hours (TRE10) and a continuous measure of deviation from an individual’s median eating window (TWD). Linear mixed-effects models and functional data analysis were used to examine independent and temporal associations of glucose levels with TRE and dietary intakes.

Results TRE10 was associated with reduced mean amplitude of glycemic excursions (MAGE) (β = −7.15, P = 0.031) and glucose standard deviation (SD) (β = −2.16, P = 0.035), with the strongest associations around 09:00. TWD was positively associated with glycemic coefficient of variation (CV) (β = 0.36, P = 0.050) and higher glucose levels between 07:00 and 08:00. Carbohydrate intake was significantly associated with time in range (TIR) and glycemic variability, with notable glucose changes at 10:00 and 21:00. Dietary vitamin D intake was linked to reduced glycemic area under the curve (AUC) (β = −0.29, P = 0.040), with pronounced effects at 12:00 and 20:00. Additionally, eating windows < 10 hours attenuated carbohydrate-induced glucose spikes in the morning but amplified glucose responses in the early afternoon.

Conclusions In adults with type 2 diabetes, eating windows <10 hours and consistent eating windows improved glycemic control, with distinct time-of-day effects. These findings support integrating timing-based nutritional strategies into personalized diabetes management.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

This study was supported by City University of Hong Kong internal research grant #9610473, the Institute of Digital Medicine and the Hong Kong Innovation and Technology Commission (InnoHK Project CIMDA). The funders played no role in the design, analysis, or interpretation of the results in this study.

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Data access to the ShanghaiT2DM Dataset are available from the repository at https://figshare.com/collections/Diabetes_Datasets_ShanghaiT1DM_and_ShanghaiT2DM/6310860/2

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

AbbreviationsAUCarea under curveCGMcontinuous glucose monitoringCVcoefficient of variationFDAfunctional data analysisMAGEmean amplitude of glycemic excursionsSDstandard deviationTARtime above rangeTBRtime below rangeTIRtime in rangeTREtime-restricted eatingTRE10time-restricted eating <10hTWDtime window deviation