Dietary Habits
Conditions
Brief summary
The prevalence of type 2 diabetes (T2D) is increasing worldwide, with \ 380 M currently suffering from this chronic, debilitating disease. T2D is characterized by high blood glucose levels in the mornings and after meals. The largest hyperglycemic spike often occurs after breakfast. Targeting this meal may be a simple, feasible strategy to improve glycemic control and reduce risk for diabetes complications. It is hypothesized that consuming a low carbohydrate high fat (LCHF) breakfast for 3 months, when compared to a standard low-fat breakfast will improve blood glucose control, increase satiety and improve body composition in people with T2D. This information will test whether the simple dietary strategy of limiting carbohydrates at breakfast could help in managing T2D.
Detailed description
A 3-month parallel-group randomized controlled trial will be conducted. Eligible participants will be randomized to either the Low-carb High-fat breakfast (LCHF, n=41) or a low-fat standard care control breakfast (CTL, n=41), to be consumed daily for a period of 3 months. Due to COVID-19 pandemic, this study was adapted to be conducted remotely through video/telephone conference meetings between participants and study staff, along with mailing of study materials before and after the intervention for remote data collection. Each group will be provided with a menu of 8 LCHF breakfasts or 8 CTL breakfasts from which to choose each morning. Breakfast options (designed by a registered dietitian) will be controlled in macronutrient content and calories (\ 400-500 kcal), but allow for personal preference and autonomy to promote adherence.
Interventions
OTHERLow-Carb High-Fat breakfast
Participants will receive 8 low-carb high-fat breakfast meal recipes to follow daily during 3 months.
OTHERLow fat standard care control breakfast
Participants will receive 8 low-fat breakfast meal recipes to follow daily during 3 months.
Sponsors
University of Wollongong
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 79 Years
Healthy volunteers
No
Inclusion criteria
* physician-diagnosed T2D of ≥1 year; * current HbA1c of \< 8.5%; * BMI: \>25 kg/m2; (as of July 5, 2021, BMI cut off was expanded from 25-40 kg/m2 to higher than 25kg/m2 to facilitate recruitment) * blood pressure of \<160/99 mm Hg assessed according to guidelines; * non-smoking; * not on hormone replacement therapy, corticosteroids, or anti-inflammatory medications; * 20-79 years old.
Exclusion criteria
* Use of exogenous insulin; * taking more than 2 glucose lowering medications; * ongoing medical treatment for diseases such as cancer, auto-immune or inflammatory disease, liver or kidney disorders; * allergy, intolerance or aversion to eggs or any other dietary restrictions (e.g., vegan, breakfast skipping) that will prevent them from following the standardized study diets; * being unable to follow remote guidance by internet or smartphone * being unable to follow the controlled diet instructions;.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline Hemoglobin A1c at 12 Weeks | Baseline to 12 weeks of diet | Hemoglobin A1c measured at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline Fasting Blood Insulin at 12 Weeks | Baseline to 12 weeks of diet | Average fasting blood insulin measured at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast |
| Change From Baseline Blood Lipids at 12 Weeks | Baseline to 12 weeks of diet | Mean triglycerides, total, HDL, and LDL cholesterol at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfas |
| Change From Baseline Inflammation Marker High Sensitive Reactive Protein (hsCRP) at 12 Weeks | Baseline to 12 weeks of diet | Blood inflammation marker (hsCRP) at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast |
| Hunger/Satiety Levels | Weeks 1, 6 and 12 | Levels of hunger and satiety measured by a 0 to 100 millimeter visual analog scale \[ranges across a continuum from none (0) to an extreme amount (100) of Hunger, Satiety, Fullness, Appetite\] How hungry do you feel? How satisfied do you feel? How full do you feel? How much food do you think you can eat? |
| Change From Baseline Fasting Blood Glucose at 12 Weeks | Mean values for the first 14 days (weeks 1-2) and mean values for the last 14 days (weeks 11-12) of the intervention | Mean fasting blood glucose from 14 days measured at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast |
| Change From Baseline Body Weight at 12 Weeks | Baseline to 12 weeks of diet | Body weight measured in kilograms at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast |
| Change From Baseline Body Mass Index at 12 Weeks | Baseline to 12 weeks of diet | Body mass Index measured in weight in kilograms divided by the square of height in meters at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast |
| Continuous Glucose Monitoring | Mean values for the first 14 days (weeks 1-2) and mean values for the last 14 days (weeks 11-12) of treatment | Measures of overall glucose control by continuous glucose monitoring device |
| Dietary Intake | Mean dietary intake assessed during the 12-week intervention | Dietary calorie intake assessed by three 3-day food records during the 12-week intervention |
Countries
Canada
Participant flow
Pre-assignment details
121 were included in analysis according to intention-to-treat principle
Participants by arm
| Arm | Count |
|---|---|
| Low-Carb High-Fat Breakfast Participants followed a daily low carbohydrate high fat breakfast intervention for 3 months.
Low-Carb High-Fat breakfast: Participants received 8-10 low-carb high-fat breakfast meal recipes to follow daily during 3 months. | 60 |
| Low Fat Standard Care Control Breakfast Participants followed a daily low fat standard care control breakfast intervention for 3 months.
Low fat standard care control breakfast: Participants received 8 low-fat breakfast meal recipes to follow daily during 3 months. | 61 |
| Total | 121 |
Baseline characteristics
| Characteristic | Low Fat Standard Care Control Breakfast | Total | Low-Carb High-Fat Breakfast |
|---|---|---|---|
| Age, Continuous | 64 years STANDARD_DEVIATION 10 | 64 years STANDARD_DEVIATION 9 | 65 years STANDARD_DEVIATION 9 |
| BMI (kg/m2) | 31.4 kg/m2 STANDARD_DEVIATION 6.2 | 32.3 kg/m2 STANDARD_DEVIATION 7.3 | 33.2 kg/m2 STANDARD_DEVIATION 8.2 |
| Duration of T2D, mean (SD), years | 9 years STANDARD_DEVIATION 6 | 9 years STANDARD_DEVIATION 7 | 10 years STANDARD_DEVIATION 8 |
| HbA1c (%) | 7.0 percent STANDARD_DEVIATION 0.7 | 7.0 percent STANDARD_DEVIATION 0.7 | 6.9 percent STANDARD_DEVIATION 0.8 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Region of Enrollment Australia | 24 participants | 46 participants | 22 participants |
| Region of Enrollment Canada | 37 participants | 75 participants | 38 participants |
| Sex: Female, Male Female | 35 Participants | 64 Participants | 29 Participants |
| Sex: Female, Male Male | 26 Participants | 57 Participants | 31 Participants |
| Waist Circumference (cm) | 109.6 centimeters STANDARD_DEVIATION 15.7 | 110.2 centimeters STANDARD_DEVIATION 15.9 | 111.1 centimeters STANDARD_DEVIATION 16.2 |
| Weight (kg) | 90.8 kilograms STANDARD_DEVIATION 18.8 | 93.3 kilograms STANDARD_DEVIATION 22.9 | 95.8 kilograms STANDARD_DEVIATION 26.3 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 64 | 0 / 63 |
| other Total, other adverse events | 0 / 64 | 0 / 63 |
| serious Total, serious adverse events | 0 / 64 | 0 / 63 |
Outcome results
Primary
Change From Baseline Hemoglobin A1c at 12 Weeks
Hemoglobin A1c measured at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast
Time frame: Baseline to 12 weeks of diet
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Low-Carb High-Fat Breakfast | Change From Baseline Hemoglobin A1c at 12 Weeks | -0.3 % of HbA1c |
| Low Fat Standard Care Control Breakfast | Change From Baseline Hemoglobin A1c at 12 Weeks | -0.1 % of HbA1c |
Secondary
Change From Baseline Blood Lipids at 12 Weeks
Mean triglycerides, total, HDL, and LDL cholesterol at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfas
Time frame: Baseline to 12 weeks of diet
Population: Blood samples were not collected for triglycerides.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Low-Carb High-Fat Breakfast | Change From Baseline Blood Lipids at 12 Weeks | Total cholesterol | -0.3 % change |
| Low-Carb High-Fat Breakfast | Change From Baseline Blood Lipids at 12 Weeks | HDL cholesterol | -3.6 % change |
| Low-Carb High-Fat Breakfast | Change From Baseline Blood Lipids at 12 Weeks | cholesterol/HDL ratio | 13 % change |
| Low-Carb High-Fat Breakfast | Change From Baseline Blood Lipids at 12 Weeks | non-HDl cholesterol | 5.9 % change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Blood Lipids at 12 Weeks | non-HDl cholesterol | -1.9 % change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Blood Lipids at 12 Weeks | Total cholesterol | -5.9 % change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Blood Lipids at 12 Weeks | cholesterol/HDL ratio | 6 % change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Blood Lipids at 12 Weeks | HDL cholesterol | -3.8 % change |
Secondary
Change From Baseline Body Mass Index at 12 Weeks
Body mass Index measured in weight in kilograms divided by the square of height in meters at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast
Time frame: Baseline to 12 weeks of diet
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Low-Carb High-Fat Breakfast | Change From Baseline Body Mass Index at 12 Weeks | -1.2 %change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Body Mass Index at 12 Weeks | -1.1 %change |
Secondary
Change From Baseline Body Weight at 12 Weeks
Body weight measured in kilograms at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast
Time frame: Baseline to 12 weeks of diet
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Low-Carb High-Fat Breakfast | Change From Baseline Body Weight at 12 Weeks | -1.2 % change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Body Weight at 12 Weeks | -0.9 % change |
Secondary
Change From Baseline Fasting Blood Glucose at 12 Weeks
Mean fasting blood glucose from 14 days measured at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast
Time frame: Mean values for the first 14 days (weeks 1-2) and mean values for the last 14 days (weeks 11-12) of the intervention
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Low-Carb High-Fat Breakfast | Change From Baseline Fasting Blood Glucose at 12 Weeks | First 14 days | 7.0 mmol/L | Standard Deviation 1.3 |
| Low-Carb High-Fat Breakfast | Change From Baseline Fasting Blood Glucose at 12 Weeks | Last 14 days | 7.0 mmol/L | Standard Deviation 1.3 |
| Low Fat Standard Care Control Breakfast | Change From Baseline Fasting Blood Glucose at 12 Weeks | First 14 days | 7.6 mmol/L | Standard Deviation 1.9 |
| Low Fat Standard Care Control Breakfast | Change From Baseline Fasting Blood Glucose at 12 Weeks | Last 14 days | 7.6 mmol/L | Standard Deviation 1.7 |
Secondary
Change From Baseline Fasting Blood Insulin at 12 Weeks
Average fasting blood insulin measured at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast
Time frame: Baseline to 12 weeks of diet
Population: Due to logistics and budget, samples were not collected for insulin measurement.
Secondary
Change From Baseline Inflammation Marker High Sensitive Reactive Protein (hsCRP) at 12 Weeks
Blood inflammation marker (hsCRP) at baseline and after 12 weeks of following the low-carbohydrate breakfast or low-fat breakfast
Time frame: Baseline to 12 weeks of diet
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Low-Carb High-Fat Breakfast | Change From Baseline Inflammation Marker High Sensitive Reactive Protein (hsCRP) at 12 Weeks | 10 % change |
| Low Fat Standard Care Control Breakfast | Change From Baseline Inflammation Marker High Sensitive Reactive Protein (hsCRP) at 12 Weeks | -6 % change |
Secondary
Continuous Glucose Monitoring
Measures of overall glucose control by continuous glucose monitoring device
Time frame: Mean values for the first 14 days (weeks 1-2) and mean values for the last 14 days (weeks 11-12) of treatment
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Low-Carb High-Fat Breakfast | Continuous Glucose Monitoring | Fasting glucose first 14 days | 6.5 mmol/L | Standard Deviation 1.5 |
| Low-Carb High-Fat Breakfast | Continuous Glucose Monitoring | Fasting glucose last 14 days | 7.0 mmol/L | Standard Deviation 1.9 |
| Low Fat Standard Care Control Breakfast | Continuous Glucose Monitoring | Fasting glucose first 14 days | 6.5 mmol/L | Standard Deviation 1.5 |
| Low Fat Standard Care Control Breakfast | Continuous Glucose Monitoring | Fasting glucose last 14 days | 6.8 mmol/L | Standard Deviation 1.7 |
Secondary
Dietary Intake
Dietary calorie intake assessed by three 3-day food records during the 12-week intervention
Time frame: Mean dietary intake assessed during the 12-week intervention
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Low-Carb High-Fat Breakfast | Dietary Intake | total energy | 1701 kilocalories | Standard Deviation 510 |
| Low-Carb High-Fat Breakfast | Dietary Intake | total carbohydrate energy | 601 kilocalories | Standard Deviation 225 |
| Low-Carb High-Fat Breakfast | Dietary Intake | total protein energy | 347 kilocalories | Standard Deviation 102 |
| Low-Carb High-Fat Breakfast | Dietary Intake | total fat energy | 753 kilocalories | Standard Deviation 251 |
| Low Fat Standard Care Control Breakfast | Dietary Intake | total fat energy | 719 kilocalories | Standard Deviation 255 |
| Low Fat Standard Care Control Breakfast | Dietary Intake | total energy | 1927 kilocalories | Standard Deviation 480 |
| Low Fat Standard Care Control Breakfast | Dietary Intake | total protein energy | 325 kilocalories | Standard Deviation 112 |
| Low Fat Standard Care Control Breakfast | Dietary Intake | total carbohydrate energy | 883 kilocalories | Standard Deviation 288 |
Secondary
Hunger/Satiety Levels
Levels of hunger and satiety measured by a 0 to 100 millimeter visual analog scale \[ranges across a continuum from none (0) to an extreme amount (100) of Hunger, Satiety, Fullness, Appetite\] How hungry do you feel? How satisfied do you feel? How full do you feel? How much food do you think you can eat?
Time frame: Weeks 1, 6 and 12
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How hungry do you feel? week 1 | 22 score on a scale (mm) | Standard Deviation 18 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How satisfied do you feel? week 1 | 69 score on a scale (mm) | Standard Deviation 17 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How full do you feel? week 1 | 72 score on a scale (mm) | Standard Deviation 21 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How much food do you think you can eat? week 1 | 46 score on a scale (mm) | Standard Deviation 25 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How hungry do you feel? week 6 | 26 score on a scale (mm) | Standard Deviation 21 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How satisfied do you feel? week 6 | 65 score on a scale (mm) | Standard Deviation 21 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How full do you feel? week 6 | 72 score on a scale (mm) | Standard Deviation 19 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How much food do you think you can eat? week 6 | 49 score on a scale (mm) | Standard Deviation 24 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How hungry do you feel? week 12 | 29 score on a scale (mm) | Standard Deviation 25 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How satisfied do you feel? week 12 | 64 score on a scale (mm) | Standard Deviation 21 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How full do you feel? week 12 | 70 score on a scale (mm) | Standard Deviation 22 |
| Low-Carb High-Fat Breakfast | Hunger/Satiety Levels | How much food do you think you can eat? week 12 | 48 score on a scale (mm) | Standard Deviation 23 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How full do you feel? week 12 | 66 score on a scale (mm) | Standard Deviation 23 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How hungry do you feel? week 1 | 27 score on a scale (mm) | Standard Deviation 23 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How full do you feel? week 6 | 67 score on a scale (mm) | Standard Deviation 22 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How satisfied do you feel? week 1 | 70 score on a scale (mm) | Standard Deviation 19 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How satisfied do you feel? week 12 | 64 score on a scale (mm) | Standard Deviation 22 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How full do you feel? week 1 | 69 score on a scale (mm) | Standard Deviation 23 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How much food do you think you can eat? week 6 | 46 score on a scale (mm) | Standard Deviation 25 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How much food do you think you can eat? week 1 | 47 score on a scale (mm) | Standard Deviation 25 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How much food do you think you can eat? week 12 | 43 score on a scale (mm) | Standard Deviation 25 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How hungry do you feel? week 6 | 26 score on a scale (mm) | Standard Deviation 22 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How hungry do you feel? week 12 | 26 score on a scale (mm) | Standard Deviation 23 |
| Low Fat Standard Care Control Breakfast | Hunger/Satiety Levels | How satisfied do you feel? week 6 | 65 score on a scale (mm) | Standard Deviation 22 |