Dietary Intervention, Fasting, Time Restricted, Glycemic Response; Satiety, Postprandial Glucose
Conditions
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.
Detailed description
This study is a randomized crossover interventional trial conducted in healthy adults to evaluate the effect of a high-protein, high-fiber pre-fast meal on subjective satiety and glycemic responses during fasting hours. Each participant will complete two study conditions in a randomized sequence: a high-protein, high-fiber pre-fast meal condition and a low-protein, low-fiber pre-fast meal condition. Each condition will be followed for two consecutive days and separated by a three-day washout period to minimize potential carryover effects. During the high-protein, high-fiber condition, participants will consume a standardized pre-fast meal consisting of oats (40 g), Greek yogurt (160 g), peanut butter (16 g), dried cranberries (10 g), and almonds (6 g). Meals will be provided in pre-measured portions by the research team. During the low-protein, low-fiber condition, participants will receive standardized written dietary instructions, including a list of foods to avoid, to guide consumption of a low-protein, low-fiber pre-fast meal. No calorie restriction will be applied in either study condition. Subjective appetite sensations, including hunger, fullness, desire to eat, and prospective food consumption, will be assessed using visual analogue-type scales at predefined time points across the fasting day. Glycemic profiles will be continuously assessed using continuous glucose monitoring (CGM). Exploratory analyses will examine temporal associations between CGM-derived glucose levels and glucose trends and subjective appetite sensations across the study day.
Interventions
OTHERHigh-Protein, High-Fiber Meal
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.
OTHERLow-Protein, Low-Fiber Meal
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.
Sponsors
King Faisal University
Saudi Food and Drug Authority
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Adults aged 18 years and older * Willingness to comply with study procedures, including fasting and continuous glucose monitoring * Ability to provide informed consent
Exclusion criteria
* 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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Daytime Satiety During Fasting Hours | 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. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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. | Interstitial glucose levels assessed using continuous glucose monitoring (CGM) to evaluate glucose patterns and variability during fasting hours. |
| Post-Meal CGM Glucose Response | 0-120 minutes after the pre-fast meal during each intervention condition. | Continuous glucose monitoring-derived glucose response in the 0-120 minutes following consumption of the pre-fast meal, including peak glucose and incremental area under the curve (iAUC). |
Countries
Saudi Arabia
Contacts
CONTACTWafa Alotaibi
Outcome results
None listed