 [ Symptoms ] i woke up with swollen parotid glands [ Disease ] there is no data on this as yet how long you fast once a month three times a week is an issue as well what kind of fast are we talking about scientists have been studying severe caloric restriction for years in animals you might say they are kept in a state of semi starvation indeed these animals do have a lower incidence of some medical conditions but at what price no one can ask the animals if they are enjoying any of this on the other hand keeping total calories under control with a healthy lifestyle that includes physical activity is a reasonable way to rein in calories and achieve an optimal life span