Designing a Co-created Intervention to Promote Motivation and Maintenance of Time-Restricted Eating in Individuals With Overweight and Type 2 Diabetes

Protocol for a 1-year randomised, controlled, parallel group, open-label trial on the effects and feasibility of time-restricted eating in individuals with type 2 diabetes- The REStricted Eating Time in the treatment of type 2 diabetes (RESET2) trial

AIM

Time-restricted eating (TRE) limits the time for food intake to typically 6-10 h/day without other dietary restrictions. The aim of the RESET2 (the REStricted Eating Time in the treatment of type 2 diabetes) trial is to investigate the effects on glycaemic control (HbA1c) and the feasibility of a 1-year TRE intervention in individuals with overweight/obesity and type 2 diabetes. The aim of the present paper is to describe the protocol for the RESET2 trial.

METHODS

RESET2 is a randomised, controlled, parallel-group, open-label trial. One hundred and sixty individuals with type 2 diabetes (HbA1c >53 mmol/mol (>7.0%)), and Body Mass Index ≥25 kg/m2 will be randomised to standard care plus TRE, or to standard care and habitual living. Both the intervention and control group will follow standard diabetes care including regular clinical visits 3-4 times/year. The intervention is divided into two periods: (1) a 3-month TRE period with a fixed eating window with a self-selected timing to obtain data from the participants' experiences with TRE and (2) a 9-month individually adjusted TRE period. Participants in the TRE group will be instructed to reduce their eating window by a minimum of 3 h/day compared to the habitual eating window and with an eating window of 8-10 h/day. Test days will be scheduled at baseline, after 3 months and after 1 year. The primary outcome is HbA1c (evaluated 3 months and 1 year after randomisation) and secondary outcomes are body weight, fat mass, continuous glucose monitoring derived time-in-range and use of antidiabetic medicine (evaluated 1 year after randomisation). Additionally, we will conduct a process evaluation to assess whether the TRE intervention functioned as hypothesised.

Time-Restricted Eating is a Feasible Dietary Strategy in the Treatment of Complicated Type 2 Diabetes: The RESET2 Pilot Study

OBJECTIVE

To investigate the feasibility of a 12-week time-restricted eating (TRE) intervention targeting people with overweight/obesity and complicated type 2 diabetes to inform the design of a 1-year randomized controlled trial.

METHODS

In this single-arm pilot study, 20 participants with overweight/obesity and complicated type 2 diabetes were recruited from the diabetes clinics at Hvidovre Hospital and Steno Diabetes Center Copenhagen in the Greater Copenhagen area, Denmark. Participants followed 8 weeks of strict 10-hour TRE, followed by a 4-week TRE period with individual adjustments and support options.

RESULTS

Nineteen participants completed the intervention. Median (quartile 1-quartile 3) adherence to the eating window across all 12 weeks was 94% (86-98). Mean (95% confidence interval) reductions in body weight of -2.0 kg (-2.9 to -1.1) and hemoglobin A1c of -0.4% (-0.6 to -0.1) were observed. Participants expressed that the individualized options added flexibility to the eating concept, enabled the maintenance of social life, and eased challenging times with TRE.

CONCLUSIONS AND IMPLICATIONS

Twelve weeks of TRE was feasible. Individualized adjustments and support may have the potential to facilitate the maintenance of long-term TRE.

Navigating challenges and adherence in time-restricted eating: A qualitative study

AIMS

Adherence to any dietary approach is crucial for achieving long-term benefits. This qualitative study aims to explore the facilitators and barriers to adherence, and how individuals in community settings navigate time-restricted eating in their daily lives.

METHODS

Semi-structured, in-depth interviews were conducted with 21 participants who had practised time-restricted eating (confining the daily eating window to <10h a day; and excluding periodic fasting methods like the 5:2 approach or alternate day fasting) for periods ranging from 3 months to more than 5 years. A qualitative content analysis, underpinned by the Capability-Opportunity-Motivation-Behaviour Model, identified multiple facilitators, barriers, and strategies that evolved over the practice.

RESULTS

Key facilitators included the simplicity and versatility of time-restricted eating, maintaining a non-obsessive and non-dieting mindset, and having a supportive environment. Barriers included hunger and food cravings, an obsessive mindset during the initial stages, and conflicting schedules with social eating occasions, including holidays. Participants employed several coping strategies to successfully navigate adherence and reported confidence in maintaining time-restricted eating as a lifestyle that contributes to better health and weight management.

CONCLUSION

Our findings suggest that successful implementation of time-restricted eating in community settings requires flexibility and viewing it as more than a short-term weight loss tool. Guidelines are needed to help individuals and practitioners implement better practices and promote healthier behaviours.

Exploring the effects of time-restricted eating on body weight and associated cardiometabolic outcomes in South African women living with HIV (TESSA): protocol for a randomised controlled trial

INTRODUCTION

We codesigned an intervention with a low-resourced community with the aim to investigate the effects of time-restricted eating (TRE) on changes in body weight and associated cardiometabolic outcomes in South African women living with overweight/obesity and HIV who have initiated dolutegravir (DTG)-based antiretroviral therapy (ART).

METHODS AND ANALYSIS

Women with overweight or obesity (body mass index ≥25 kg/m², no upper limit), aged 20-45 years, living with HIV and in a low-resourced community, and receiving DTG-based ART for less than 2 years will be recruited from a community healthcare centre in Khayelitsha, Cape Town (n=152). Participants will be randomised 1:1 to the TRE group (n=76) or standard of care control group (n=76) for 12 months. The TRE group will be required to restrict their eating window to ~8-10 hours/day and will receive nutritional information sessions at baseline and at 3, 6, 9 and 12 months. The primary outcome of body weight will be assessed at baseline and monthly. Cardiometabolic measures will be reported as secondary outcomes. At baseline, 6- and 12 months, an oral glucose tolerance test (to estimate insulin sensitivity and beta-cell function), questionnaires (sociodemographic, food insecurity, quality of life, social support and sleep quality) and a quantified food frequency questionnaire (total energy and macronutrient composition) will be completed. Every 3 months, appetite ratings, bioelectrical impedance (fat mass and fat-free mass), fasting venous bloods (glucose, insulin, gut hormones and systemic inflammation) and process evaluation (qualitative interviews) will be completed. Monthly monitoring will also include anthropometry and blood pressure.

ETHICS AND DISSEMINATION

The study is conducted in accordance with the Declaration of Helsinki and has been approved by the Human Research Ethics Committee of the University of Cape Town (628/2021). Verbal and written consent is required from study participants. Results of this study will be published in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

PACTR202302484999720.

Randomized Controlled Feasibility Trial of Late 8-Hour Time-Restricted Eating for Adolescents With Type 2 Diabetes

Background

No trial to date has tested the effects of late time-restricted eating (lTRE) on glycemic control or body composition in adolescents with type 2 diabetes (T2D).

Objective

The objective of the current study was to examine the feasibility, acceptability, and preliminary efficacy of lTRE compared to a prolonged eating window in adolescents with T2D.

Design

A 12-week, randomized, controlled, feasibility study of lTRE compared to control in adolescents with obesity and new onset T2D was conducted.

Participants/setting

Eligible participants were 13-21 years old; with a diagnosis of T2D, on metformin monotherapy, recruited from Children's Hospital Los Angeles, between January 2021 and December of 2022. From 36 eligible participants, 27 were enrolled (75% recruitment rate; age: 16.5 ± 1.7 years, HbA1c: 6.6 ± 0.9%, 22/27 [81%] Hispanic, 17/27 [63%] female, 23/27 [85%] public insurance; all p-values >.05), and 23 of 27 completed the protocol.

Intervention

Participants wore a continuous glucose monitor (CGM) daily and were randomized to one of two meal-timing schedules for 12-weeks: (1) lTRE (eating all food between 12:00 PM and 20:00 PM without calorie counting or recommended daily caloric intake) or (2) Control (eating over a period of 12 or more hours per day).

Main outcome measures

Study recruitment, retention and adherence to intervention arms were captured to operationalize feasibility. Glucose control (HbA1c), weight loss (%BMIp95), total body fat mass on DEXA, sleep, and dietary intake were explored as secondary outcomes.

Statistical Analysis

Analyses were based on the intention to treat (ITT) population. Between-group differences in clinical outcomes were assessed using mixed-effects longitudinal regression models.

Results

Overall adherence to the 8-hr lTRE was 6.2 ± 1.1 d/wk and Control was 5.9 ± 0.9 d/wk. Participants assigned to lTRE indicated that limiting their eating window did not negatively affect their daily functioning and no adverse events were reported. In this pilot study, lTRE led to a reduction in %BMIp95 (-3.4%-95%CI: -6.1, -0.7, p = 0.02), HbA1c (-0.4%, 95%CI: -0.9, -0.01, p = .06), and ALT (-31.1 U/L, 95%CI: -60, -2, p = .05) within the group. There was no significant difference observed between lTRE and control across these measures (all p > .05). The lTRE group had a -271.4 (95% CI, -565.2, 5.2) kcal/day energy reduction compared to a +293.2 (95% CI: 30.4, 552.7) kcal/day increase in Control (p = .01). There were no significant changes observed in sleep or eating behaviors over the study period between groups.

Conclusions

Recruitment and retention rates suggest a trial of lTRE in adolescents with T2D was feasible. lTRE was seen as acceptable by participants and adherence was high. A revised intervention, building on the successful elements of this pilot alongside adapting implementations strategies to augment adherence and engagement, should therefore be considered.

Effects of 3 months of 10-h per-day time-restricted eating and 3 months of follow-up on bodyweight and cardiometabolic health in Danish individuals at high risk of type 2 diabetes: the RESET single-centre, parallel, superiority, open-label, randomised controlled trial

BACKGROUND

Time-restricted eating (TRE) has been suggested to be a simple, feasible, and effective dietary strategy for individuals with overweight or obesity. We aimed to investigate the effects of 3 months of 10-h per-day TRE and 3 months of follow-up on bodyweight and cardiometabolic risk factors in individuals at high risk of type 2 diabetes.

METHODS

This was a single-centre, parallel, superiority, open-label randomised controlled clinical trial conducted at Steno Diabetes Center Copenhagen (Denmark). The inclusion criteria were age 30-70 years with either overweight (ie, BMI ≥25 kg/m2) and concomitant prediabetes (ie, glycated haemoglobin [HbA1c] 39-47 mmol/mol) or obesity (ie, BMI ≥30 kg/m2) with or without prediabetes and a habitual self-reported eating window (eating and drinking [except for water]) of 12 h per day or more every day and of 14 h per day or more at least 1 day per week. Individuals were randomly assigned 1:1 to 3 months of habitual living (hereafter referred to as the control group) or TRE, which was a self-selected 10-h per-day eating window placed between 0600 h and 2000 h. Randomisation was done in blocks varying in size and was open for participants and research staff, but outcome assessors were masked during statistical analyses. The randomisation list was generated by an external statistician. The primary outcome was change in bodyweight, assessed after 3 months (12 weeks) of the intervention and after 3 months (13 weeks) of follow-up. Adverse events were reported and registered at study visits or if participants contacted study staff to report events between visits. This trial is registered on ClinicalTrials.gov (NCT03854656).

FINDINGS

Between March 12, 2019, and March 2, 2022, 100 participants (66 [66%] were female and 34 [34%] were male; median age 59 years [IQR 52-65]) were enrolled and randomly assigned (50 to each group). Of those 100, 46 (92%) in the TRE group and 46 (92%) in the control group completed the intervention period. After 3 months of the intervention, there was no difference in bodyweight between the TRE group and the control group (-0·8 kg, 95% CI -1·7 to 0·2; p=0·099). Being in the TRE group was not associated with a lower bodyweight compared with the control group after subsequent 3-month follow-up (-0·2 kg, -1·6 to 1·2). In the per-protocol analysis, participants who completed the intervention in the TRE group lost 1·0 kg (-1·9 to -0·0; p=0·040) bodyweight compared with the control group after 3 months of intervention, which was not maintained after the 3-month follow-up period (-0·4 kg, -1·8 to 1·0). During the trial and follow-up period, one participant in the TRE group reported a severe adverse event: development of a subcutaneous nodule and pain when the arm was in use. This side-effect was evaluated to be related to the trial procedures.

INTERPRETATION

3 months of 10-h per-day TRE did not lead to clinically relevant effects on bodyweight in middle-aged to older individuals at high risk of type 2 diabetes.

FUNDING

Novo Nordisk Foundation, Aalborg University, Helsefonden, and Innovation Fund Denmark.