Daf Yomi - Yoma 80 - Yom Kippur's Eating is Different

The Gemora states that in order to be liable for eating on Yom Kippur, one must eat food the size of a date. This must be eaten in the time it takes to eat a פרס - half a loaf.

By all other prohibitions in the Torah, there is a halacha that one must eat it in the normal manner in order to be liable. The Shagas Aryeh rules that if one eats raw meat on Yom Kippur, he would have violated the Torah's prohibition. This is because the Torah does not state by Yom Kippur "Don't eat," rather the Torah states "you should be afflicted." It therefore does not have the standard guidelines of eating.

The Ksav Sofer rules, based on this, that if one ate before Yom Kippur an amount less than a date and on Yom Kippur ate more which accumalatively equals a date and he is satiated, he will be liable for eating on Yom Kippur. This again can only be understood by saying that we must distinguish between the 'eating' on Yom Kippur and elsewhere. This person did not eat the full amount on Yom Kippur and yet has violated the trangression. On Yom Kippur, the prohibition is not to eat in a manner that will lead to satisfaction. The Achiezer discusses if one would be allowed to have food inserted through intravenous. The reason to say that it is not permitted is because the Torah is not particular on the action of eating, rather the satiation that comes from it.

This could be the explanation in our Gemora. Even though one who eats food in the amount of a date in a longer span that it would take to eat a half a loaf is considered eating, however he is not satiated through this and hence not liable.