Shema Yimashech Achar Shulchano-
What does it mean? He'll get up, leave the sukkah, and eat outside of the sukkah? Or, that he'll reach for the food and for a few moments, while he's reaching, his head and perhaps Rov Gufo will be outside of the sukkah?
Dovid Hirsch, Jerusalem
Sholom Rav,
The Tana's explanation "Shema Yimashech achar Shulchno' suggests the former reason. In any event, Chazal would certainly not have issued a decree on account of the second reason alone, seeing as it is not Asur to take a bite outside the Sukkah.
In general, when asking She'eilos of this nature, one should contend with the possibility that Chazal, with their broad outlook, had both reasons in mind.
Be'Virchas Kol Tuv,
Eliezer Chrysler