Dear Rov. If someone has to eat during Yom Kippur and he has the option to first eat small amounts which are less that the Shiur that is set for the Biblical prohibition. But then as the day goes by he may have to actually eat a larger amount that is already the Shiur, is it already better to eat a large amount at the beginning and then he wont have to eat a number of also prohibited smaller amounts. What is more correct?

Igrois Moishe (4: 121), Kovetz Halochos (31: 37) and others maintain that if he won’t have to eat a large amount later, it is better to just eat many smaller amounts. See Piskei Teshuvos (620: 2).