Effect of Post-exercise Nutrition on Glycemia in Women (PEN)

Influence of Post-exercise Greek Yogurt on 24 h Glycemic Control in Women With Overweight/Obesity

The purpose of this study is to assess whether post-exercise Greek yogurt following a single session of aerobic exercise improves metabolic and musculoskeletal health in women with overweight/obesity.

Study Overview

• Status: Recruiting
• Conditions: Overweight and Obesity
• Intervention / Treatment: Behavioral: Greek yogurt; Behavioral: Exercise; Behavioral: Carbohydrate-based study supplement

Detailed Description

Following the acquisition of informed consent, eligibility to participate in the study will be determined using questionnaires. Participants will undergo baseline testing at our laboratory at the University of Toronto to determine cardiorespiratory fitness, body composition and undergo exercise familiarization.

Eligible participants will be assigned, in a random order, to two metabolic trials approximately 4 weeks apart that involve 4 days of controlled diet and exercise. Each trial takes place over 4 days, but participants are not required to come to the laboratory on all days. The two trials involve: 1) Exercise + Greek Yogurt (GY) 2) Exercise + a carbohydrate-based study supplement (SS).

During the 4 day trials, participants consume controlled diets and the study supplements (GY and SS). On 1 of these days participants will perform exercise in our lab followed by the consumption of GY or SS. Various outcomes will be measured throughout the trial, including glycemic control (via continuous glucose monitoring), fat oxidation, appetite and health outcomes in blood samples.

Throughout the duration of the study, participants will be asked to maintain their habitual diet and physical activity patterns, and maintain their current body weight.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jenna Gillen, PhD; Phone Number: 14169783244; Email: jenna.gillen@utoronto.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M4K 1V2
      • Recruiting
      • Jenna Gillen
      • Contact: Jenna Gillen; Email: jenna.gillen@utoronto.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18-45 yrs
• BMI ≥27 kg/m2
• Elevated waist circumference (≥88 cm)
• ≤2 structured exercise sessions/week
• Weight stable (within ± 2kg for at least 6 months)
• Experiencing regular natural menstrual cycles
• Non-smoker

Exclusion Criteria:

• Allergy to dairy foods
• Diagnosed lactose intolerance or an aversion to foods provided during the study (e.g., post-exercise snacks)
• Previous history of cardiovascular or metabolic disease
• The use of medication for managing blood glucose or lipid metabolism
• Current use of oral contraceptives or use within the last 3 months
• Irregular menstrual cycles (<21 days or >35 days)
• Pregnant or lactating
• Recreational tobacco or cannabis use
• Inability to perform the study exercise protocols
• Actively engaging in a low-carbohydrate diet (e.g., ketogenic, Atkins).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High-intensity interval exercise and post-exercise Greek yogurt (HIIE+GY); Participants will consume greek yogurt following a single session of exercise	Behavioral: Greek yogurt; Following 2 days of controlled diet, participants will consume greek yogurt following high-intensity interval exercise; Behavioral: Exercise; Following 2 days of controlled diet, participants will perform high-intensity interval exercise following an overnight fast
Active Comparator: High-intensity interval exercise and post-exercise carbohydrate study supplement (HIIE +SS); Participants will consume a carbohydrate-based study supplement following a single session of exercise	Behavioral: Exercise; Following 2 days of controlled diet, participants will perform high-intensity interval exercise following an overnight fast; Behavioral: Carbohydrate-based study supplement; Following 2 days of controlled diet, participants will consume a carbohydrate-based study supplement following high-intensity interval exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial glycemia	Postprandial glucose exposure assessed using continuous glucose monitoring	24 hour post-exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
24 hours average glucose	Average glucose concentration over 24 hours	24 hours post-exercise
Nocturnal glucose	Overnight glucose concentration	6-8 hours
Nocturnal glucose	Overnight glucose exposure (area under the curve)	6-8 hours
Glycemic variability	Continuous overall net glycemic action (CONGA)	24 hours
Glycemic variability	Standard deviation (SD)	24 hours
Glycemic variability	Coefficient of variation (%CV)	24 hours
Post-exercise fat oxidation	Fat oxidation assessed with indirect calorimetry	1, 2 and 3 hours post-exercise
Fasting glucose concentration	Venous blood sampling	24 hours post-exercise
Fasting insulin concentration	Venous blood sampling	24 hours post-exercise
Fasting insulin resistance	Homeostasis Model Assessment (HOMA2)	24 hours post-exercise
Bone metabolism	Serum concentration of CTX	30, 90, and 180 minutes and 24 hours post-exercise
Bone metabolism	Serum concentration of OPG	30, 90, and 180 minutes and 24 hours post-exercise
Bone metabolism	Serum concentration of RANKL	30, 90, and 180 minutes and 24 hours post-exercise
Bone metabolism	Serum concentration of OC	30, 90, and 180 minutes and 24 hours post-exercise

Collaborators and Investigators

• Sponsor: University of Toronto
• Investigators: Principal Investigator: Jenna Gillen, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Actual): May 24, 2023
• Primary Completion (Estimated): April 1, 2024
• Study Completion (Estimated): April 1, 2024

Study Registration Dates

• First Submitted: May 5, 2023
• First Submitted That Met QC Criteria: May 16, 2023
• First Posted (Actual): May 25, 2023

Study Record Updates

• Last Update Posted (Actual): June 2, 2023
• Last Update Submitted That Met QC Criteria: May 30, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: exercise; women; glycemic control
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Body Weight; Obesity; Overweight
• Other Study ID Numbers: 42756-3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No