Fasting is voluntarily refraining from eating for a set period of time and has been used for many years for therapeutic and spiritual purposes. Intermittent fasting (IF) is defined as a variety of eating patterns where no or few calories are consumed for periods of time than can span 12 hours to several days, on a recurring basis, and can result in a number of different physiological responses. Time restricted fasting (TRF) is a specific type of IF in which food intake is restricted to specific time periods of the day, typically between 13 and 18 hours. TRF has been shown to improve glycemic control, increase fat oxidation, and has the potential to improve insulin signaling. This is all due in part to the increased levels of ketone bodies produced when fasting.