A Trial on the GI of Spaghetti Versus Rice as Mixed Meals

Study Overview
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Brief Summary
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Pasta and rice are two of the most commonly consumed grains worldwide, where the former has a low GI (e.g. spaghetti) and the latter, usually (as it depends on the type) has a higher GI (e.g. white rice). The most typical ways in which pasta and rice are consumed are with the addition of oil or tomato sauce, and are recommended to be consumed in this way in the Mediterranean diet. The Mediterranean diet has been demonstrated to reduce the risk of cardiovascular disease, improve glycemic control and is encouraged in many clinical guidelines globally for both cardiovascular risk reduction. Some studies have explored the differences in glycemic response of different carbohydrate foods consumed with the addition of fat demonstrating that the glycemic response is indeed reduced.However, the GI may remain of importance even when other means to reduce glycemic response are introduced. The investigators therefore designed a randomized controlled crossover study to explore whether the addition of fat in the form of commonly consumed sauces which are recommended as part of a Mediterranean diet, affects the difference in glycemic response between a commonly consumed low GI and a higher GI carbohydrate food.

Detailed Description
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Background: Pasta and rice are two of the most commonly consumed grains worldwide, where the former has a low GI (e.g. spaghetti) and the latter, usually (as it depends on the type) has a higher GI (e.g. white rice). Low GI foods have been demonstrated to improve glycemic control, insulin sensitivity and diabetes management, and have been associated with reduced risk of chronic disease, including coronary heart disease. Therefore, GI is of importance as a potential dietary strategy to reduce postprandial glycemia and improve glycemic control, particularly with the increasing rates of diabetes. Several studies have demonstrated how the addition of fat to a meal can reduce the glycemic response, some of which have suggested in a dose response manner. The mechanism by which increasing fat reduces the glycemic response may be through the effects on gastric emptying. Fat may modulate the gut hormones cholecystokinin (CCK) and peptide YY, which delay gastric emptying, which is known to be a major determinant of postprandial glycemia where small changes can have a substantial effect. Low GI foods result in lower glycemic excursions compared to higher GI foods, which, in addition to gastric emptying, may exert this effect through various pathways. Thus, there is importance of exploring the potential additional benefit beyond reducing the glycemic response with the addition of fat. The most typical ways in which pasta and rice are consumed are with the addition of oil or tomato sauce, and are recommended to be consumed in this way in the Mediterranean diet. Among many benefits, the Mediterranean diet has been demonstrated to reduce the risk of cardiovascular disease, improved glycemic control and is encouraged in many clinical guidelines globally for both cardiovascular risk reduction and for diabetes. Some studies have explored the differences in glycemic response of different carbohydrate foods consumed with the addition of fat demonstrating that the glycemic response is indeed reduced.However, the GI may remain of importance even when other means to reduce glycemic response are introduced. The investigators therefore designed a randomized controlled crossover study to explore whether the addition of fat in the form of commonly consumed sauces which are recommended as part of a Mediterranean diet, affects the difference in glycemic response between a commonly consumed low GI and a higher GI carbohydrate food. Objective: To assess whether the addition of fat to a low GI and higher GI carbohydrate food lowers the glycemic response equivalently, thus whether the difference between the low and higher GI food is preserved. Scope: The principal scope of the study is to evaluate the impact of two carbohydrate-containing foods varying in glycemic index, spaghetti and rice, on postprandial glucose. To confirm that the two foods vary in GI, the GI of the rice will first be tested in Part A, since the GI of spaghetti has already been determined in the investigator's lab. In Part B of the study, following the consumption of the test foods by healthy volunteers (see Study Design), the investigators will evaluate the differences in postprandial glucose, as well as insulin and c-peptide. Implications: These results will determine whether there is an independent effect of the GI of a carbohydrate containing food when fat is added to a meal in the context of how is it commonly and recommended to be consumed. These results may be useful to encourage the use of low GI foods for greater improvements in glycemic and insulinemic control, which is an important public health concern in today's global society.

Official Title
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The Importance of Glycemic Index on Postprandial Glycemia and Insulinemia in the Context of the Addition of Fat to Carbohydrate Foods: A Randomized Controlled Trial on Spaghetti Versus Rice as Mixed Meals

Conditions
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Dietary Modification

Intervention / Treatment
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* Other: Glucose #1
* Other: Glucose #2
* Other: Glucose #3
* Other: Spaghetti
* Other: Rice
* Other: Spaghetti + Tomato Sauce
* Other: Rice + Tomato Sauce
* Other: Spaghetti + Pesto
* Other: Rice + Pesto


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: generally healthy Exclusion Criteria: BMI≥30kg/m2 have any health conditions (including anemia and metabolic conditions such as hypertension, dyslipidemia, impaired glucose intolerance or diabetes) have celiac disease perform intense physical activity (LAF ≥2.10 - LARN 2014) currently taking any prescription medication for chronic diseases (including psychiatric) dietary supplements affecting the metabolism Women who are pregnant or breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Glucose #1<br>50 grams of available carbohydrate from glucose monohydrate will be dissolved in 250mL water and consumed as a test meal | Other: Glucose #1<br>* 50g available carbohydrate<br>* Other names: Glucose Monohydrate;|
| Active Comparator: Spaghetti<br>50 grams of available carbohydrate from spaghetti will be cooked according to package instructions and consumed as a test meal | Other: Spaghetti<br>* 50g available carbohydrate<br>|
| Active Comparator: Rice<br>50 grams of available carbohydrate from white rice will be cooked according to package instructions and consumed as a test meal | Other: Rice<br>* 50g available carbohydrate<br>* Other names: white rice;|
| Active Comparator: Spaghetti + tomato sauce<br>50 grams of available carbohydrate from spaghetti plus tomato sauce (1:1 ratio) will be cooked according to package instructions and consumed as a test meal | Other: Spaghetti + Tomato Sauce<br>* 50g available carbohydrate<br>|
| Active Comparator: Rice + tomato sauce<br>50 grams of available carbohydrate from white rice plus tomato sauce (1:1 ratio) will be cooked according to package instructions and consumed as a test meal | Other: Rice + Tomato Sauce<br>* 50g available carbohydrate<br>* Other names: white rice + tomato sauce;|
| Active Comparator: Spaghetti + Pesto<br>50 grams of available carbohydrate from spaghetti plus pesto sauce (1:0.5 ratio) will be cooked according to package instructions and consumed as a test meal | Other: Spaghetti + Pesto<br>* 50g available carbohydrate<br>|
| Active Comparator: Rice + Pesto<br>50 grams of available carbohydrate from white rice plus pesto sauce (1:0.5 ratio) will be cooked according to package instructions and consumed as a test meal | Other: Rice + Pesto<br>* 50g available carbohydrate<br>* Other names: white rice + pesto;|
| Other: Glucose #2<br>50 grams of available carbohydrate from glucose monohydrate will be dissolved in 250mL water and consumed as a test meal | Other: Glucose #2<br>* 50g available carbohydrate<br>* Other names: Glucose Monohydrate;|
| Other: Glucose #3<br>50 grams of available carbohydrate from glucose monohydrate will be dissolved in 250mL water and consumed as a test meal | Other: Glucose #3<br>* 50g available carbohydrate<br>* Other names: Glucose Monohydrate;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glycemic Index | postprandial response for glucose (IAUC); Comparisons will be made between the spaghetti and rice IAUCs in each of the 3 contexts (alone, with tomato sauce, with pesto) | 2 hours (-10 and 0 -fasting-, 15, 30, 45, 60, 90, 120 minutes) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial Insulin | postprandial response for plasma insulin (IAUC) | 2 hours (-10 and 0 -fasting-, 15, 30, 45, 60, 90, 120 minutes) | 
| Postprandial C-peptide | postprandial response for plasma c-peptide (IAUC) | 2 hours (-10 and 0 -fasting-, 15, 30, 45, 60, 90, 120 minutes) | 
| Peak Glucose | maximum value of postprandial glucose response | 2 hours (-10 and 0 -fasting-, 15, 30, 45, 60, 90, 120 minutes) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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glycemic index