Effect of Kefir on Appetite

Study Overview
=================
Brief Summary
-----------------
This study aimed to determine the effect of kefir on appetite in healthy subjects. A randomized, single-blind, and 3-intervention crossover trial included 22 healthy and normal-weight (BMI 18.5-25 kg/m2) females aged 21-24 years. Participants were recruited to three test meals: an LGI-Milk, an LGI-Kefir, and an HGI-Kefir, with a one-week washout period. Appetite ratings were measured at 0, 15, 30, 60, 90, 120, 150, and 180 minutes. At the end of three hours, participants were served an ad libitum lunch meal. Then, the foods eaten at lunch were recorded and their energy and nutrient analysis was calculated.

Official Title
-----------------
Effect of Kefir on Appetite

Conditions
-----------------
Appetitive Behavior

Intervention / Treatment
-----------------
* Other: LGI-Milk Breakfast
* Other: LGI-Kefir Breakfast
* Other: HGI-Kefir Breakfast


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy Normal-weight (BMI 18.5-25 kg/m2) Female 21-24 years Exclusion Criteria: During the last three months, change more than 5 kg in body weight or following an energy-restricted diet Being a vegan Having any chronic diseases such as diabetes, hypertension, etc. Physician-diagnosed medications or conditions that influence metabolism Smoking Practicing endurance sports Having difficulties with swallowing/eating Lack of appetite Hypersensitivity for the foods understudy Pregnant or lactating

Ages Eligible for Study
-----------------
Minimum Age: 21 Years
Maximum Age: 24 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Screening
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: LGI-Milk Breakfast<br>Low glycemic index and milk content (LGI-Milk) breakfast as a test meal | Other: LGI-Milk Breakfast<br>* This test meal with low glycemic index and milk were served as a breakfast after 12-hours fasting and participants were asked to consume the meal in full, within 15 min.<br>|
| Experimental: LGI-Kefir Breakfast<br>Low glycemic index and kefir content (LGI-Kefir) breakfast as a test meal | Other: LGI-Kefir Breakfast<br>* In crossover design, this test meal with low glycemic index and kefir was served as a breakfast to compare the LGI-Milk Breakfast.<br>|
| Experimental: HGI-Kefir Breakfast<br>High glycemic index and kefir content (HGI-Kefir) breakfast as a test meal | Other: HGI-Kefir Breakfast<br>* In crossover design, this test meal with high glycemic index and kefir was served as a breakfast to compare the LGI-Milk Breakfast and the LGI-Kefir Breakfast.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hunger rating | Subjective assessment of appetite sensations was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How hungry do you feel? (not at all hungry - as hungry as I ever felt) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and hunger rating was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Fullness rating | Subjective assessment of appetite sensations was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How full do you feel? (not at all full - totally full) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and fullness rating was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a better outcome. | Three hours postprandial period | 
| Desiring to eat | Subjective assessment of appetite sensations was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How strong is your desire to eat? (very weak - very strong) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and desiring to eat was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Prospective food consumption | Subjective assessment of appetite sensations was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How much do you think you can eat? (no food at all - a large amount of food) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and prospective food consumption was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Composite appetite score | The separate visual analog scale factors like hunger, fullness, desiring for eat, and prospective food consumption were combined to produce an additional measure termed 'composite appetite score'. This average appetite score was computed for 0, 15, 30, 60, 90, 120, 150 and 180 minutes using the following equation: [(hunger + desire to eat + prospective food consumption + (100 - fullness)]/4 Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Subsequent energy consumption | Energy intake at ad libitum lunch was calculated. | Three hours after the test breakfast | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Desiring for sweet | Subjective assessment of desire for specific food types was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question Would you like to eat something sweet? (No, not at all - Yes, very much) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and desiring for sweet was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Desiring for salty | Subjective assessment of desire for specific food types was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question Would you like to eat something salty? (No, not at all - Yes, very much) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and desiring for salty was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Desiring for savoury | Subjective assessment of desire for specific food types was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question Would you like to eat something savoury? (No, not at all - Yes, very much) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and desiring for savoury was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Desiring for fatty | Subjective assessment of desire for specific food types was performed by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question Would you like to eat something fatty? (No, not at all - Yes, very much) at time points 0, 15, 30, 60, 90, 120, 150 and 180 minutes, and desiring for fatty was quantified as AUC (mm x min), which was calculated according to the trapezoidal rule by using those VAS scores. Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Three hours postprandial period | 
| Visual appeal of test meal | Palatability of test meals was measured by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How is the visual appeal of test meal? (Good - Bad) at time points 15 minutes (immediately after consuming test meal). Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Immediately after consuming test meal (at 15 min) | 
| Smell of test meal | Palatability of test meals was measured by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How is the smell of test meal? (Good - Bad) at time points 15 minutes (immediately after consuming test meal). Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Immediately after consuming test meal (at 15 min) | 
| Taste of test meal | Palatability of test meals was measured by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How is the taste of test meal? (Good - Bad) at time points 15 minutes (immediately after consuming test meal). Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Immediately after consuming test meal (at 15 min) | 
| Aftertaste of test meal | Palatability of test meals was measured by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question Is there any perceived taste in your mouth after test meal? (Much - None) at time points 15 minutes (immediately after consuming test meal). Total scale score changes in a range of 0-100. Higher values represent a better outcome. | Immediately after consuming test meal (at 15 min) | 
| Palatability of test meal | Palatability of test meals was measured by using a visual analog scale (VAS) composed of lines (of 100 mm in length) with words anchored at each end, expressing the most positive and the most negative rating. VAS ratings were measured by using a question How is the palatability of test meal? (Good - Bad) at time points 15 minutes (immediately after consuming test meal). Total scale score changes in a range of 0-100. Higher values represent a worse outcome. | Immediately after consuming test meal (at 15 min) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Appetite, Probiotic, Glycemic index