Endurance Training and Post-exercise Low Glycemic Index Recovery Diet for Improving Postprandial Triglycerides

Low Versus High-glycemic Index Post-exercise Diets for Improving Metabolism and Body Composition

Sponsors

Lead sponsor: University of Saskatchewan

Collaborator: Heart and Stroke Foundation of Canada

Source University of Saskatchewan
Brief Summary

Postprandial triglycerides are a strong risk factor for heart disease. The purpose is to assess the effects of a low-glycemic versus high-glycemic meal after 90 minute exercise sessions that are done 4 times a week for 6 weeks on postprandial triglyceride level. Secondary measurements include other lipids and body composition.

Detailed Description

The increase in triglycerides after a meal (i.e. postprandial triglycerides) is a strong risk factor for cardiovascular disease. Overweight/obese individuals have a greater triglyceride response to the same meal compared to lean individuals; therefore they are at greater risk. If exercise is performed the evening before a high-fat breakfast, the postprandial levels of triglycerides after the breakfast are reduced; however, if high glycemic index (GI) foods are consumed after the exercise session, the benefits of exercise on next-day postprandial triglycerides is negated. The investigators recently showed (HSFC funded) that consuming low GI foods after exercise is similar to fasting after exercise and superior to consumption of high GI foods for lowering next-day postprandial triglycerides. Low GI food was also superior for increasing fat oxidation, and lowering insulin, and low and very low density lipoproteins and preventing a decrease in high density lipoproteins. The benefits of an acute exercise session followed by low GI food consumption is now clear; however, it is not known whether this practice over weeks of exercise training results in accumulated and sustained benefits.

The purpose of this study is to determine the chronic effects of consuming low compared to high GI foods after exercise sessions over six weeks in overweight and obese individuals.

Twenty-four overweight and obese males and females will be randomized to consume either high or low GI foods immediately after exercise sessions (four sessions per week, 90 minutes per session, six weeks). At all other times of the day over the six weeks, they will be supplied a moderate GI diet, with calories and macronutrients based on four-day food diaries completed before the study. Two weeks before the intervention, participants will be required to go on the moderate GI diet, as a lead-in. One week into the lead-in, a baseline test will be done to determine postprandial metabolic responses (i.e. triglycerides, low and very low density lipoproteins, high density lipoproteins, insulin, and fat oxidation) after a morning high-fat breakfast. A week later, the same postprandial testing will be carried out the morning after the first exercise and post-exercise consumption of a low or high GI recovery meal. Participants will continue the training and post-exercise food consumption for the next six weeks, with postprandial measures taken again following the final exercise and feeding session. Body composition and aerobic fitness will be determined before and after the six week intervention.

The investigators hypothesize that the low GI post-exercise feeding will be superior to the high GI post-exercise feeding for reducing body fat, improving fat oxidation, and reducing postprandial triglycerides, insulin and other harmful lipids. The results of the study will provide clinicians, exercise professionals and dietitians unique and experimentally tested strategies for their clients to lose body fat and improve metabolic profiles, to reduce the risk of heart disease.

Overall Status Recruiting
Start Date July 15, 2018
Completion Date December 30, 2019
Primary Completion Date September 30, 2019
Phase N/A
Study Type Interventional
Primary Outcome
Measure Time Frame
Postprandial triglycerides Change from baseline to 1 week and 6 weeks
Secondary Outcome
Measure Time Frame
Postprandial cholesterol Change from baseline to 1 week and 6 weeks
Postprandial low density lipoprotein Change from baseline to 1 week and 6 weeks
Postprandial high density lipoprotein Change from baseline to 1 week and 6 weeks
Postprandial glucose Change from baseline to 1 week and 6 weeks
Postprandial insulin Change from baseline to 1 week and 6 weeks
Fasting Triglyceride Change from baseline to 1 week and 6 weeks
Fasting cholesterol Change from baseline to 1 week and 6 weeks
Fasting LDL-cholesterol Change from baseline to 1 week and 6 weeks
Fasting HDL-cholesterol Change from baseline to 1 week and 6 weeks
Fasting glucose Change from baseline to 1 week and 6 weeks
Fasting Insulin Change from baseline to 1 week and 6 weeks
Postprandial fat oxidation Change from baseline to 1 week and 6 weeks
Fat mass Change from baseline to 6 weeks
Waist Girth Change from baseline to 6 weeks
Enrollment 24
Condition
Intervention

Intervention type: Dietary Supplement

Intervention name: Low glycemic index post-exercise diet

Description: Feeding of a low-glycemic index, lentil meal after 90 minutes of walking exercise

Arm group label: Low glycemic index post-exercise diet

Intervention type: Dietary Supplement

Intervention name: High glycemic index post-exercise diet

Description: Feeding of a high-glycemic index meal (i.e. instant mashed potatoes, white bread, egg whites) after 90 minutes of walking exercise

Arm group label: High glycemic index post-exercise diet

Eligibility

Criteria:

Inclusion Criteria:

- Overweight or obese (BMI 25 or greater)

Exclusion Criteria:

- Smokers

- Diabetic

- Taking medications that affect carbohydrate or lipid metabolism

Gender: All

Minimum age: 18 Years

Maximum age: 44 Years

Healthy volunteers: Accepts Healthy Volunteers

Overall Contact

Last name: Philip Chilibeck, PhD

Phone: 306-966-1072

Email: [email protected]

Location
facility status contact contact_backup investigator
University of Saskatchewan Recruiting Philip D Chilibeck, Ph.D. 3069661072 [email protected] Philip Chilibeck, Ph.D. Principal Investigator Gordon Zello, Ph.D. Sub-Investigator
Location Countries

Canada

Verification Date

October 2018

Responsible Party

Responsible party type: Principal Investigator

Investigator affiliation: University of Saskatchewan

Investigator full name: Phil Chilibeck

Investigator title: Professor

Has Expanded Access No
Condition Browse
Number Of Arms 2
Arm Group

Arm group label: Low glycemic index post-exercise diet

Arm group type: Experimental

Description: Lentil-based post-exercise meal

Arm group label: High glycemic index post-exercise diet

Arm group type: Active Comparator

Description: Instant potato, white bread, and egg white post-exercise meal

Patient Data No
Study Design Info

Allocation: Randomized

Intervention model: Parallel Assignment

Primary purpose: Prevention

Masking: None (Open Label)

Source: ClinicalTrials.gov