TestDiet^® 21^st Century Western Diet™ Series

Traditional “western” diets.  To study the effects of a “typical” modern diet of North America and Europe, a number of versions of a “Western Diet” had been developed by various researchers and manufacturers; these diets were characterized by:

·         ≈ 4.5 kcal /gram

·         ≈ 40% kcal from milkfat

·         ≈ 15-16% kcal from protein

·         ≈ 0.2% cholesterol

Other research has used “DIO Diets” for diet-induced obesity; these diets were characterized by:

·         ≈ 4.7- 5.2 kcal /gram

·         ≈ 45% - 60% kcal from lard

·         ≈ 18% kcal from protein

·         ≈ 0.02% cholesterol

Each of these types of diets utilized just one ingredient (milkfat or lard) as the primary source of energy from fat.  (A small amount of vegetable oil would be included to supply essential fatty acids.)

Pro-active in vivo diet development research.  We have conducted extensive research regarding the use of diets to induce various disease models and other phenotypes, in particular metabolic syndrome.  Our studies have been presented, in abstracts and posters, at several scientific meetings, including (spring & summer 2005) Targeting Metabolic Syndrome, The Endocrine Society, the American Diabetes Association, the Society for the Study of Ingestive Behavior, and others.  (See: Cunha TM, Peterson RG, & Gobbett TA, Differing sources of dietary fat alter the character of metabolic syndrome induced in the C57BL/6 mouse. May, 2005)

This study and extensive consultation with several dozen researchers led to the development of a completely new and innovative series of purified ingredient rodent diets—the TestDiet^® 21^st Century Western Diet™ Series.  The objective is to mimic "typical" human "western" diets (North American/European).  Generally the typical human does not develop metabolic syndrome, obesity, diabetes, atherosclerosis, hypertension, and other diseases from diets that derive their fat almost exclusively from one source, such as lard or butter.  Rather, the typical “western” diet includes a variety of saturated fats; it also derives essential fatty acids (EFA) from multiple sources, and includes both soluble and insoluble fiber.

The diets in this new series are based on the AIN-93G rodent diet, which provides optimal protein and fat, a variety of carbohydrate sources, and appropriate vitamins and minerals.  In this diet series, the basic AIN diet parameters have been modified to include both corn oil and soy oil as sources of essential fatty acids; three different sources of saturated fats—lard, hydrogenated vegetable oil (“Crisco”), and anhydrous milkfat; and, as sources of fiber, inulin (soluble) in addition to the customary cellulose (insoluble). 

This "calorie-balanced" approach is becoming the method of choice in most studies.  It recognizes that animals tend to eat "to calorie" rather than "to quantity."  Thus, it is important to assure that when the same amount of calories are consumed that approximately the same amount of micronutrients, fiber, protein and, in this case, cholesterol are consumed.  In any event, using a "calorie-balanced" diet assures that the subjects' basic nutritional requirements are not compromised. 

TestDiet^® 21^st Century Western Diet™ Series               comparative chart (PDF)

Click on each link for complete diet formulas and nutritional profiles

Custom modifications.  If the researcher prefers, these formulas can be infinitely modified: e.g., the amount of cholesterol can be maintained at a constant 0.15% (or whatever level), the percentage of fiber by weight can be made approximately constant, or the TBHQ preservative can be removed (most purified diets do not contain it).  Furthermore, while the color-coding can be very advantageous in conducting the studies, collecting the data, and reporting the results, we can remove it.

*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.

Comparative Chart

Click here for a printable PDF version of a comprehensive comparison chart