Carbohydrate Modifications to Purified Diets
We can alter the carbohydrate concentration of any purified diet; diets with high and low carbohydrate concentrations are possible. Carbohydrate levels are usually adjusted by making adjustments to either the protein level or fat level of the diet. These formulas can be "calorie-balanced" or "quantity-balanced." (For more information see About Diet Formulas.)
Typically, the sources of carbohydrates in purified diets are sucrose ("table sugar," a simple carbohydrate metabolized quickly) and dextrin ("cornstarch," a complex carbohydrate metabolized far more slowly). Depending upon the research purpose of the diet, the ratio of these carbohydrates will vary. For example, certain diets have been formulated to provide all the carbs from sucrose, with a matching diet obtaining all the carbs from cornstarch in order to study the diabetogenic effect of simple and complex carbohydrates.
Cholesterol – Cholic Acid – Atherosclerosis Note: Many diets with added cholesterol also incorporate cholic acid (sodium cholate) to very effectively facilitate cholesterol absorption/utilization. However, cholic acid appears to be contraindicated for atherosclerosis studies and is not used by most researchers for such studies. Diet formulas can be modified to eliminate cholic acid.
Examples of Carbohydrate-Modified Purified Diets –
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TestDiet® # |
"Quantity-Balanced" |
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High Carbohydrate (70%) Modification to Basal Diet 5755 1 |
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Low Carbohydrate (1.9%) Modification to Basal Diet 5755 1 |
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"Calorie-Balanced" |
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"Surwit" (73.1% kcal, 74.3% by weight carbohydrate with cornstarch) |
58R0 |
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"Surwit" (73.1% kcal, 74.3% by weight carbohydrate with sucrose) |
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"Surwit" (25.5% kcal, 35.5% by weight carbohydrate with cornstarch) |
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"Surwit" (25.5% kcal, 35.5% by weight carbohydrate with sucrose) |
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TestDiet® DIO Series (65.8% kcal, 64.7% by weight carbohydrate) |
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TestDiet® DIO Series (36.4% kcal, 42.7% by weight carbohydrate) |
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TestDiet® DIO Series (21.4% kcal, 27.8% by weight carbohydrate) |
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"van Heek" (71.5% kcal, 67.3% by weight carbohydrate) |
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"van Heek" (35.9% kcal, 41.4% by weight carbohydrate) |
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"van Heek" (20.6% kcal, 26.3% by weight carbohydrate) |
See also:
Carbohydrate Modifications to LabDiet® Formulas
References:
1 Margolskee RF, et al. 2007. T1R3 and gustducin in gut sense sugars to regulate expression of Na+-glucose cotransporter 1. Proc. Natl. Acad. Sci. USA. 104(38): 15075-80.