Nicotinamide adenine dinucleotide (NAD) is a coenzyme that is required for the conversion of fuels into energy and for other metabolic processes. Circadian oscillation is the 24 hour process by which organisms have sleep and activity cycles. Molecules in organs such as the liver and the brain may also have circadian oscillations that enable these behaviors. The NAD metabolome is the set of compounds related to NAD including NADP, nicotinamide and ADP-ribose that mark different metabolic processes. Our objectives was to determine how the NAD metabolome oscillates in liver and brain in mice that were exposed to two different diets: normal chow or a ketogenic diet, rich in fat and low in carbohydrates. Here we show how diet alters the NAD metabolome in two organs in the mouse. In our experimentation we observed that in the cortex, the oscillations tend to be diurnal rather than circadian when fed in normal chow.