Is expiation obligatory every time a vow is broken, or is one expiation sufficient to be released from a lifelong vow not to eat until satiated, or to eat while watching television or listening to the radio?

The phrase "I vowed not to eat until I am full" is a vow of justification, and you are required to offer a single expiation if you eat until you are full, or if you eat while watching television or listening to the radio. The expiation is not repeated unless the phrasing of the vow indicates repetition. The expiation for an ambiguous vow here is the expiation for an oath: freeing a slave, or feeding ten poor people, or clothing them. If one cannot find any of these, then they must fast for three days.