I have been wondering why when using a model of high fat diet the control diet has to be the 10% fat instead of normal chow. Does anybody understand the rationale behind this?
The main reason is that you don’t really know the composition of the normal chow diet. As it is a maintenance diet, providers use different batches of cereals and the compositions varies a lit bit between lots. Using a marching diet you ensure all micronutrients are balanced between the diets, and all macronutrients are always the same amounts since the providers use the same sources according to your specification and use specific calculations to get the % you want.