This talk will focus on the myriad factors that impact obesity, with particular attention on the complexity of hormone signaling, the role of estrogen, and the importance of testosterone on autophagy. It will also explore the impacts of fasting on the hormones and the gut microbiome, and its connection to healthy aging, as well as the current clinical evidence to support fasting with food for metabolic benefits and rejuvenation. Participants will learn about the health benefits and clinical application of fasting, and more specifically fasting mimicking diets (FMD), which are also known as fasting with food.