The Effect of Glycaemic Index Variation on Blood Glucose and Mood in Healthy Participants Across the Day

Study Overview
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Brief Summary
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This study provided 24 healthy subjects with two diets that varied in their glycaemic index values. One condition was a low GI diet, whilst the other was a high GI diet. Glucose concentrations and mood were measured throughout each test day.

Detailed Description
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Therefore, the aim of this study is to feed to participants meals which differing in their glycaemic index across the course of a day, and thus produce different glycaemic responses. The outcome variables will be blood glucose levels and subjective mood. The purpose of this study is to identify the appropriate times (according to glycaemic response) at which cognitive functioning should be tested. Importantly, this study is also the first step to characterizing glycaemic and cognitive profiles associated with food consumption over a whole day (breakfast, lunch, snack) rather than just one meal (e.g. breakfast), ranging from the most favourable (stable glucose regulation) to the least favourable (variability; many peaks and troughs).

Official Title
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The Effect of Glycaemic Index Variation on Blood Glucose and Mood in Healthy Participants Across the Day

Conditions
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Mood, Diet Modification, Glucose, Low Blood, Glucose, High Blood

Intervention / Treatment
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* Dietary Supplement: Low Glycaemic Diet
* Dietary Supplement: High Glycaemic Diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 18 and 65 years of age. Willing to participate in the entire study (signed informed consent required) Subjects will be eligible for the study if male or female (not pregnant or lactating) Exclusion Criteria: Diabetic Smoker Have any food intolerances or allergies History of alcohol or drug misuse Diagnosed with any of the following: High blood cholesterol High blood pressure Thyroid disorder Heart problems, stroke or any vascular disease in the past 12 months Inflammatory diseases such as rheumatoid arthritis Bone related conditions, such as osteoporosis Renal, gastrointestinal, respiratory, liver disease or cancer You are presently taking part in another clinical trial or research study You are an elite athlete (very high intensity training more than 3 times a week) You are currently on a specific diet or taking any dietary supplements and are unwilling to cease during the testing period You are intending to regularly use medication which affects gastrointestinal motility

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: All participants took part in both diet conditions
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low GI diet<br>This diet contained three meals, all with a low GI value. This was the Low Glycaemic Diet intervention. | Dietary Supplement: Low Glycaemic Diet<br>* This intervention consisted of three low GI meals.<br>|
| Experimental: High GI diet<br>This diet contained three meals, all with a high GI value. This was the High Glycaemic Diet intervention. | Dietary Supplement: High Glycaemic Diet<br>* This intervention consisted of three meals, all with a high GI value.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Glycaemic profile across the day | Change in blood glucose concentrations (mmol/L) | Assessed at 0 (baseline), 15, 30, 45, 60, 90, 120 mins after each meal. With 3 meals in a day this totaled 21 assessment point for each day, giving 42 assessment points to compare overall. Data will be reported for the duration of this 3 year PhD award. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mood (alertness, anxiety and contentment) measured by Bond & Lader (1974) Visual Analogue Scale | The Bond & Lader VAS provides participants with 16 lines measuring 100mm each. At the ends of each line are two words opposite in meaning. For example, 'alert' and 'drowsy'. A participants marks on the line closer to the word they currently feel. The score from each line is out of 0 to 100. | This was measured 6 times a day (every 90 minutes starting at 0 minutes/baseline), giving a total of 12 times. Each time last approximately 5 minutes, giving a total of 60 minutes overall. Data will be reported for the duration of this 3 year PhD award. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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mood, glycaemic index, glucose, diet