Effect of a High-Protein, High-Fiber Pre-Fast Meal on Satiety and Glycemic Profiles During Fasting

NCT07447505 | Recruiting

• 1 other identifier: KFU-2026-ETHICS3958
• Study Type: interventional
• Target: 38
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized crossover study investigates the effect of consuming a high-protein, high-fiber pre-fast meal on subjective satiety and glycemic responses during fasting hours in healthy adults. Participants will complete two dietary conditions in a randomized order: a standardized high-protein, high-fiber pre-fast meal and a low-protein, low-fiber pre-fast meal guided by dietary instructions. Each condition will be followed for two consecutive days and separated by a three-day washout period. Outcomes include subjective appetite sensations during fasting hours, glycemic profiles assessed using continuous glucose monitoring (CGM), and exploratory analyses examining the association between glucose dynamics and appetite sensations.

Conditions

Glycemic Response; Satiety; Fasting, Time Restricted; Dietary Intervention; Postprandial Glucose

Outcome Measures

Primary Outcomes (1)

• Daytime Satiety During Fasting Hours

  Subjective appetite sensations including hunger, fullness, desire to eat, and prospective food consumption assessed using a visual analogue-type scale with numeric anchors ranging from 0 to 10.

  Assessed at baseline prior to the pre-fast meal, 30 and 60 minutes post-meal, mid-afternoon (approximately 4:00 PM), and 30 minutes prior to breaking the fast during each intervention condition.

Secondary Outcomes (2)

• Glycemic Profiles During Fasting (CGM)

  Assessed on Day 1 and Day 2 of each intervention period during the fasting window from completion of the pre-fast meal until breaking the fast.

• Post-Meal CGM Glucose Response

  0-120 minutes after the pre-fast meal during each intervention condition.

Other Outcomes (1)

• Association Between Glucose and Appetite (Exploratory)

  Assessed on Day 1 and Day 2 of each intervention period at the predefined appetite assessment time points: baseline prior to the pre-fast meal, 30 minutes post-meal, 60 minutes post-meal, 4:00 PM, and 30 minutes prior to breaking the fast.

Study Arms (2)

High-Protein, High-Fiber Pre-Fast Meal

EXPERIMENTAL

Participants consume a standardized high-protein, high-fiber pre-fast meal for two consecutive days.

Other: High-Protein, High-Fiber Meal

Low-Protein, Low-Fiber Pre-Fast Meal

ACTIVE COMPARATOR

Participants follow standardized written dietary instructions to consume a low-protein, low-fiber pre-fast meal for two consecutive days.

Other: Low-Protein, Low-Fiber Meal

Interventions

High-Protein, High-Fiber Meal OTHER

Participants consume a standardized high-protein, high-fiber pre-fast meal consisting of oats (40 g), Greek yogurt (160 g), peanut butter (16 g), dried cranberries (10 g), and almonds (6 g) for two consecutive days.

High-Protein, High-Fiber Pre-Fast Meal

Low-Protein, Low-Fiber Meal OTHER

Participants follow standardized written dietary instructions, including a list of foods to avoid, to consume a low-protein, low-fiber pre-fast meal for two consecutive days. No calorie restriction is applied.

Low-Protein, Low-Fiber Pre-Fast Meal

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18 years and older
• Willingness to comply with study procedures, including fasting and continuous glucose monitoring
• Ability to provide informed consent

You may not qualify if:

• Diagnosed diabetes mellitus or known metabolic disease
• History of cardiovascular, gastrointestinal, or endocrine disorders that may affect study outcomes
• Use of medications known to affect glucose metabolism or appetite
• Pregnancy or lactation
• Known allergy or intolerance to any study meal components (oats, dairy, peanuts, nuts, cranberries)

Sponsors & Collaborators

• King Faisal University: lead
• Saudi Food and Drug Authority: collaborator

Study Sites (1)

King Faisal University

Al-Ahsa, Eastern Province, 31982, Saudi Arabia

RECRUITING

MeSH Terms

Conditions

Intermittent Fasting

Interventions

Diet, Protein-Restricted

Condition Hierarchy (Ancestors)

Fasting; Feeding Behavior; Behavior

Intervention Hierarchy (Ancestors)

Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Central Study Contacts

Wafa Alotaibi

CONTACT

+966500358622; Walotaibi@kfu.edu.sa

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: February 22, 2026
• First Posted: March 3, 2026
• Study Start: February 23, 2026
• Primary Completion: March 23, 2026
• Study Completion: March 23, 2026
• Last Updated: March 12, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

SA (1)