|10 kcal % fat||45 kcal % fat||60 kcal % fat|
One series of lab animal research diets that has been used widely is known as the VanHeek Series—our Purina TestDiet® Formulas #58Y2, #58V8, and #58Y1, also known as "D12450B," "D12451," and "D12492," respectively.
Initially, the 10 kcal% fat and 45 kcal% fat formula were used to develop an obese mouse phenotype with peripheral (but not central) resistance to the peptide leptin (Van Heek, M., D.S. Compton, C.F. France, R.P. Tedesco, A.B. Fawzi, M.P. Graziano, E.J. Sybertz, C.D. Strader, and H.R. Davis. (1997) Diet induced obese mice develop peripheral, but not central resistance to leptin”. J. Clin. Invest. 99:385-390). Later the 60 kcal% version was developed, and these three diets have been used in hundreds of subsequent studies over the past ten years.
Other manufacturers of these diets present them as providing 10%, 45%, and 60% kcal from fat, respectively. In fact, this presentation is erroneous, because casein is reported as being 100% protein, when it is actually only about 90% protein. Furthermore, the ratio of simple to complex carbohydrates varies from the 45 kcal% fat diet to the 60 kcal% fat diet. These three formulas—"D12450B," "D12451," and "D12492"—are available from TestDiet® exactly as originally formulated but at more reasonable cost.