Table 1.

Macro- and select micronutrient content of diets

	Standard Chow Envigo Cat. No. 7917	Western Diet TD.96132
Energy density, kcal/g	3.0	4.5
Total fat, % kcal	14	41
Fatty acid profile, % total fat
Saturated fats	21	41
Trans fats	0	17
Monounsaturated fats	29	35
Polyunsaturated fats	50	7
Protein, % kcal	24	19
Carbohydrate, % kcal	62	41
Fiber, % kg	18	4
Choline, mg/kg	∼1,890	∼1,660

To achieve higher fat content of the WD, hydrogenated vegetable shortening and beef tallow (both 100 g/kg) were added. The following were added to the WD to increase sugar content and made up all kcal from carbohydrates: sucrose (183 g/kg), cornstarch (160 g/kg), and maltodextrin (120 g/kg). The majority of fiber in both diets was insoluble fiber. Approximately 772 mg/kg of choline in the SC was provided as supplemental choline chloride; the remainder was in other ingredients. Choline content of the WD was provided in a vitamin mix (choline from phosphatidylcholine in added fat ingredients not accounted for). Both diets contained very low amounts of l-carnitine from fishmeal (SC) or casein (WD). Both diets were irradiated. SC, standard chow; WD, Western diet.