A Novel Diet Approach to Combat Gestational Diabetes

Study Overview
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Brief Summary
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There is an urgent need to implement novel diet approaches to combat the increasing rates of gestational diabetes mellitus (GDM). The primary aim of this study is to establish the feasibility of time-restricted eating in pregnancy, to prepare for future larger controlled trials in this research project to determine the efficacy of time-restricted eating in women at risk of GDM. Expectations: Women who have an increased risk of GDM will be able to adhere to time reduced eating during pregnancy. Time reduced eating will improve short-term glycemic control in pregnancy.

Official Title
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A Novel Diet Approach to Combat Gestational Diabetes

Conditions
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Diabetes, Gestational

Intervention / Treatment
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* Behavioral: time restricted eating (TRE)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: carrying one singleton live foetus in pregnancy week 12-30 having at least one risk factor for gestational diabetes mellitus (GDM) according to Norwegian guidelines for GDM screening: pre-pregnancy BMI > 25 kg/m2, GDM in previous pregnancy, primiparae aged > 25 years, first degree relative with diabetes mellitus, Asian or African ethnicity, previous delivery of new-born > 4.5 kg understand written and spoken Norwegian language Exclusion Criteria: habitual eating window < 12 hours

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Time restricted eating (TRE)<br>prolonging the duration of fasting between the last evening meal and the first meal of the next day | Behavioral: time restricted eating (TRE)<br>* Participants will attend a face-to-face meeting with the researchers at the last day of the first week of data collection (habitual diet and physical activity period) where they will be counselled to consume all food and fluid within a 8-10 h time window of their choice starting no later than 09.00 h for five weeks. During the intervention period, they will be counselled by weekly phone calls to provide encouragement, support and monitoring to improve adherence to the TRE window.<br>|
| No Intervention: control<br>Standard care. Will receive a booklet about physical activity recommendations and healthy eating in pregnancy | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in average time-window for energy intake | Average daily time-window for energy intake will be registered through log books. | Change between baseline (pre-intervention) time-window for energy intake to average time-window for energy intake during the 5-week intervention period | 
| Weekly adherence rates for time restricted eating (TRE) | The number of days per week that the participants are able to adhere to TRE, as calculated as weekly average of days with a time-window ≤ 10 hours | Weekly measures throughout the 5 week period of TRE intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perceived barriers to the protocol assessed with an unstructured interview | Participants will be asked about which barriers they perceived as challenging regarding keeping to a TRE schedule and if they have strategies to overcome these barriers. | Weekly phone calls to participants in TRE group during the 5-week intervention period and after 6 weeks | 
| Subjective appetite sensations assessed by Visual Analogue Scales | Paper line scales 100 mm on scales for Hunger (How hungry are you: From Not at all = 0 on the scale to Extremely. As hungry as I have ever felt =100 on the scale, Fullness (From Not at all = 0 on the scale to Extremely. As full as I have ever felt = 100 on the scale, Satiety (How satiated are you From Not at all =0 on the scale to Extremely =100 on the scale, Desire to eat (How strong is your desire to eat From Very weak. Extremely low = 0 on the scale to Very strong. Extremely high = 100 on the scale and Prospective consumption (quantity) (How much do you think you could (or would want to) eat right now? From Nothing at all = 0 on the scale to A very large amount = 100 on the scale. Scales will be filled in in the morning, before dinner and at bedtime. | Once weekly throughout 6 weeks, on a weekday. | 
| Change between baseline and post-intervention in fasting glucose | Post-intervention fasting glucose minus pre-intervention fasting glucose | 6 weeks | 
| Change between baseline and post-intervention in postprandial glucose | Blood glucose levels 120 minutes after ingestion of 75 g glucose (oral glucose tolerance test) | 6 weeks | 
| Change between baseline and post-intervention in fasting insulin | Circulating insulin levels | 6 weeks | 
| Change between baseline and post-intervention in postprandial insulin | Circulating insulin levels 120 minutes after ingestion of 75 g glucose. | 6 weeks | 
| Change between baseline and post-intervention blood pressure | Diastolic and systolic blood pressure | 6 weeks | 
| Change between baseline and post-intervention body mass | Body mass in kg. | 6 weeks | 
| Change in total cholesterol | Total cholesterol measured in blood | 6 weeks | 
| Change in triglycerides | Triglycerides measured in blood | 6 weeks | 
| Change in HDL cholesterol | HDL cholesterol measured in blood | 6 weeks | 
| Change in LDL cholesterol | LDL cholesterol measured in blood | 6 weeks | 
| Change in HbA1c | HbA1c measured in blood | 6 weeks | 
| Continuous glucose monitoring | Interstitial glucose measurements | 6 weeks | 
| Change between baseline and post-intervention fat mass | Fat mass in kg and percent of body mass | 6 weeks | 
| Change between baseline and post-intervention muscle mass | Muscle mass in kg | 6 weeks | 
| Change between baseline and post-intervention visceral fat area | Visceral fat area in squared cm. | 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exercise therapy, Diet, Prevention and control