Postprandial Glycemia and Satiety of Meals With Potatoes, With and Without Protein

The proposed study aims to simulate a meal eaten at home, where meals will provide a fixed amount of protein from beef or vegetarian substitute "meat" balls with ad libitum access to one of mashed potatoes, full-fat fries, or pasta. Postprandial glycemia (PPG), insulin, active ghrelin, satiety, amino acid response and food intake (FI) at the meal and again 3h later (after an ad libitum pizza meal) will be measured. In addition, post-meal PPG and satiety will be measured for one hour after the second meal.

Study Overview

• Status: Recruiting
• Conditions: Obesity; Diabetes; Appetite Regulation; Glycemic Control; Satiety Response
• Intervention / Treatment: Other: Ad libitum full-fat French fries with beef meatballs; Other: Ad libitum instant mashed potatoes with beef meatballs; Other: Ad libitum macaroni pasta with beef meatballs; Other: Ad libitum full-fat French fries with vegetarian substitute meatballs; Other: Ad libitum instant mashed potatoes with vegetarian substitute meatballs; Other: Ad libitum macaroni pasta with vegetarian substitute meatballs

Detailed Description

A total of 30 participants (15 males, 15 females) will be recruited in this study at the University of Toronto. Each participant will attend 6 study sessions where they will consume meals consisting of a fixed amount of beef or vegetarian substitute "meat" balls providing 25 g protein with ad libitum access to one of mashed potatoes, fried French fries, or pasta. Questionnaires will be filled out to assess their recent food intake, physical activity, sleep quality, stress level, appetite, physical comfort, and energy/fatigue level, as well as palatability of the food.

Blood samples will be collected at fasting and at various time points over a 3 hour period after eating the meals to measure blood glucose, insulin, active ghrelin and amino acid concentrations. After 3 hours, participants will receive an ad libitum pizza meal to assess their food intake compensation. Post-meal PPG and satiety will be measured for one hour after the pizza meal.

Study hypothesis:

1. Consumption of potatoes in their most usual forms (mashed or deep fried), when compared with pasta in either meat or vegetarian based meals result in lower FI at the meal and lower PPG and insulin.
2. Compensation for the reduced FI in the mashed potato meal does not occur at a pizza meal 3h later.
3. Lower PPG and insulin post-test meal and second meal will be found.
4. The amino acid profile of different meals will be reflected in post-prandial plasma levels and the amino acid response to vegetarian based meals with potatoes will be more balanced compared to the vegetarian based meals with pasta.

Primary objective:

To investigate the effects of potato consumption served with either meat or vegetarian substitute "meat" on meal-time FI and PPG, insulin, satiety and FI compensation at a later meal in healthy and normal weight adults. FI and PPG are primary outcomes and satiety, insulin, active ghrelin, amino acid response and FI compensation are secondary outcomes.

Specific Objectives:

Objective 1: To simulate at home-style meals and determine their effects on FI, satiety, PPG, and insulin, over three hours. Meals will be served with a fixed amount of beef or vegetarian substitute "meat" balls providing 25 g protein with ad libitum access to one of mashed potatoes, fried French fries, or pasta.

Objective 2: To determine the effect of at home-style meals with beef or a vegetarian substitute with mashed potatoes on FI compensation at an ad libitum pizza meal 3h later. Post-meal PPG and satiety will be measured for one hour.

Objective 3: To compare the amino acid response for 3 h after the meat and vegetarian based meals served with mashed potatoes, French fries, or pasta.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Amira Amr, PhD; Phone Number: 6478645258; Email: amira.amr@utoronto.ca
• Study Contact Backup: Name: Hrvoje Fabek, PhD; Phone Number: (416) 978-0799; Email: hrvoje.fabek@utoronto.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5S 3E2
      • Recruiting
      • University of Toronto - Department of Nutritional Sciences
      • Contact: Amira Amr, PhD; Phone Number: 6478645258; Email: amira.amr@utoronto.ca
      • Contact: Hrvoje Fabek, PhD; Phone Number: (416) 978-0799; Email: hrvoje.fabek@utoronto.ca
      • Principal Investigator: G. Harvey Anderson, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 43 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• > 18 and < 45 years of age
• BMI > 18.5 and < 24.9 kg/m2
• Willing to maintain habitual diet, physical activity pattern, and body weight throughout the study.
• Willing to maintain current dietary supplement use throughout the study. On test days, subject agrees not to take any dietary supplements until dismissal from the Nutrition Intervention Center. Failure to comply will result in a rescheduled test visit.
• Willing to abstain from alcohol consumption for 24h prior to all test visits.
• Willing to refrain from marijuana/ edibles use for the duration of the study (approximately 6 weeks).
• Willing to avoid vigorous physical activity for 24h prior to all test visits.
• Understanding the study procedure and willing to provide informed consent to participate in the study and authorization to release relevant protected health information to the study investigator.

Exclusion Criteria:

• Smoking
• Thyroid problems
• Previous history of cardiovascular disease, diabetes, liver or kidney disease, inflammatory bowel disease, celiac disease, short bowel syndrome, a malabsorptive syndrome, pancreatitis, gallbladder or biliary disease.
• Presence of a gastrointestinal disorder or surgeries within the past year.
• Known to be pregnant or lactating.
• Unwillingness or inability to comply with the experimental procedures and to follow our safety guidelines.
• Known intolerances, sensitivity or allergy to any ingredients in the study products.
• Extreme dietary habits (i.e Atkins diet, very high protein diets, etc.) or restrained eaters, identified by a score of ≥ 11 on the Eating Habits Questionnaire
• Uncontrolled hypertension (systolic blood pressure > 140 mm Hg or diastolic blood pressure > 90 mm Hg) as defined by the average blood pressure measured at screening.
• Weight gain or loss of at least 10lbs in previous three months.
• Excessive alcohol intake (more than 2 drinks per day or more than 9 drinks per week).
• Consuming prescription or non-prescription drug, herbal or nutritional supplements known to affect blood glucose or that could affect the outcome of the study as per investigator's judgment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ad libitum full-fat French fries with beef meatballs; Ad libitum carbohydrate side with fixed amount of protein: Ad libitum full-fat French fries with beef meatballs (25 g protein)	Other: Ad libitum full-fat French fries with beef meatballs; Participants will consume 1 of the 6 treatment meals at each of the 6 study sessions in random orders such that by the end of the study, they will have consumed all 6 treatments. Participants will be given 30 minutes to consume the treatment meal and will be instructed to eat all the meatballs but to eat the French fries ad libitum (250 g), until comfortably full, simulating "at home" meal consumption. After providing the participants with the first plate of 250 g French fries and about 120 g meatballs (25 g protein), additional plates of freshly cooked French fries (250 g) alone will be provided 10 and 20 min later and they will be given 30 min to complete the treatment meal. Each treatment will be served with water.
Experimental: Ad libitum instant mashed potatoes with beef meatballs; Ad libitum carbohydrate side with fixed amount of protein: Ad libitum instant mashed potatoes with beef meatballs (25 g protein)	Other: Ad libitum instant mashed potatoes with beef meatballs; Participants will consume 1 of the 6 treatment meals at each of the 6 study sessions in random orders such that by the end of the study, they will have consumed all 6 treatments. Participants will be given 30 minutes to consume the treatment meal and will be instructed to eat all the meatballs but to eat the mashed potatoes ad libitum (250 g), until comfortably full, simulating "at home" meal consumption. After providing the participants with the first plate of 250 g mashed potatoes and about 120 g meatballs (25 g protein), additional plates of freshly cooked mashed potatoes (250 g) alone will be provided 10 and 20 min later and they will be given 30 min to complete the treatment meal. Each treatment will be served with water.
Experimental: Ad libitum macaroni pasta with beef meatballs; Ad libitum carbohydrate side with fixed amount of protein: Ad libitum macaroni pasta with beef meatballs (25 g protein)	Other: Ad libitum macaroni pasta with beef meatballs; Participants will consume 1 of the 6 treatment meals at each of the 6 study sessions in random orders such that by the end of the study, they will have consumed all 6 treatments. Participants will be given 30 minutes to consume the treatment meal and will be instructed to eat all the meatballs but to eat the macaroni pasta ad libitum (250 g), until comfortably full, simulating "at home" meal consumption. After providing the participants with the first plate of 250 g macaroni pasta and about 120 g meatballs (25 g protein), additional plates of freshly cooked macaroni pasta (250 g) alone will be provided 10 and 20 min later and they will be given 30 min to complete the treatment meal. Each treatment will be served with water.
Experimental: Ad libitum full-fat French fries with vegetarian substitute meatballs; Ad libitum carbohydrate side with fixed amount of protein: Ad libitum full-fat French fries with vegetarian substitute meatballs (25 g protein)	Other: Ad libitum full-fat French fries with vegetarian substitute meatballs; Participants will consume 1 of the 6 treatment meals at each of the 6 study sessions in random orders such that by the end of the study, they will have consumed all 6 treatments. Participants will be given 30 minutes to consume the treatment meal and will be instructed to eat all the meatballs but to eat the French fries ad libitum (250 g), until comfortably full, simulating "at home" meal consumption. After providing the participants with the first plate of 250 g French fries and about 120 g vegetarian "meatballs" (25 g protein), additional plates of freshly cooked French fries (250 g) alone will be provided 10 and 20 min later and they will be given 30 min to complete the treatment meal. Each treatment will be served with water.
Experimental: Ad libitum instant mashed potatoes with vegetarian substitute meatballs; Ad libitum carbohydrate side with fixed amount of protein: Ad libitum instant mashed potatoes with vegetarian substitute meatballs (25 g protein)	Other: Ad libitum instant mashed potatoes with vegetarian substitute meatballs; Participants will consume 1 of the 6 treatment meals at each of the 6 study sessions in random orders such that by the end of the study, they will have consumed all 6 treatments. Participants will be given 30 minutes to consume the treatment meal and will be instructed to eat all the meatballs but to eat the mashed potatoes ad libitum (250 g), until comfortably full, simulating "at home" meal consumption. After providing the participants with the first plate of 250 g mashed potatoes and about 120 g vegetarian "meatballs" (25 g protein), additional plates of freshly cooked mashed potatoes (250 g) alone will be provided 10 and 20 min later and they will be given 30 min to complete the treatment meal. Each treatment will be served with water.
Experimental: Ad libitum macaroni pasta with vegetarian substitute meatballs; Ad libitum carbohydrate side with fixed amount of protein: Ad libitum macaroni pasta with vegetarian substitute meatballs (25 g protein)	Other: Ad libitum macaroni pasta with vegetarian substitute meatballs; Participants will consume 1 of the 6 treatment meals at each of the 6 study sessions in random orders such that by the end of the study, they will have consumed all 6 treatments. Participants will be given 30 minutes to consume the treatment meal and will be instructed to eat all the vegetarian meatballs but to eat the macaroni pasta ad libitum (250 g), until comfortably full, simulating "at home" meal consumption. After providing the participants with the first plate of 250 g macaroni pasta and about 120 g meatballs (25 g protein), additional plates of freshly cooked macaroni pasta (250 g) alone will be provided 10 and 20 min later and they will be given 30 min to complete the treatment meal. Each treatment will be served with water.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Blood Glucose Levels	Blood glucose level (mmol/L) is measured using finger prick capillary blood samples or intravenous blood samples.	Starting at the beginning of each session (0 minutes before consumption of treatment meal) and every 15-30 minutes up to 180 - 240 minutes (time of completion of each session).
Food Intake	Food intake at the treatment meal time will be measured by weighing the carbohydrates (CHO) sides plates after the assigned meal time.	After 30 minutes of the treatment meal start.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Insulin Levels	Level of blood insulin (μU/mL) is measured using finger prick capillary blood samples or intravenous blood samples.	Starting at the beginning of each session (0 minutes before consumption of treatment meal) and every 30 minutes up to 180 - 240 minutes (time of completion of each session).
Change in Active Ghrelin Levels	Active ghrelin hormone concentrations (μmol/L) is analyzed in intravenous blood samples.	Starting at the beginning of each session (0 minutes before consumption of treatment meal) and every 30 minutes up to 180 - 240 minutes (time of completion of each session).
Change in Amino Acid Response (Protein quality)	Amino acid concentrations (μmol/L) is analyzed in intravenous blood samples to determine amino acid release.	Starting at the beginning of each session (0 minutes before consumption of treatment meal) and every 30 minutes up to 180 - 240 minutes (time of completion of each session).
Food Intake Compensation	The food intake compensation after the second meal (ad libitum pizza meal) will be measured (g).	at 180 minutes after the treatment meals.
Change in Subjective Appetite	Motivation to Eat Adaptive Visual Analogue Scales measured based on a score between 0 to 100. A higher score indicates higher outcome.	up to 180 - 240 minutes (time of completion of each session)
Change in Physical comfort	Physical Comfort Visual Analogue Scales measured based on a score between 0 to 100. A higher score indicates higher outcome.	up to 180 - 240 minutes (time of completion of each session)
Change in Energy Level	Energy Level Visual Analogue Scales measured based on a score between 0 to 100. A higher score indicates higher outcome.	up to 180 - 240 minutes (time of completion of each session)
Treatment palatability	Treatment Palatability Visual Analogue Scales measured based on a score between 0 to 100. A higher score indicates higher outcome.	Immediately after treatment meal consumption
Change in Fatigue Level	Fatigue Level Visual Analogue Scales measured based on a score between 0 to 100. A higher score indicates higher outcome.	up to 180 - 240 minutes (time of completion of each session)

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Alliance for Potato Research and Education
• Investigators: Principal Investigator: G. Harvey Anderson, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2023
• Primary Completion (Estimated): December 31, 2023
• Study Completion (Estimated): April 30, 2024

Study Registration Dates

• First Submitted: October 24, 2022
• First Submitted That Met QC Criteria: November 1, 2022
• First Posted (Actual): November 9, 2022

Study Record Updates

• Last Update Posted (Actual): June 26, 2023
• Last Update Submitted That Met QC Criteria: June 23, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Insulin; Nutrition; Satiety; Appetite; Blood glucose; Ghrelin; Glycemic Control; Protein quality; Potato
• Other Study ID Numbers: 43406

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