No it wasn't the Prophet's sunnah to throw non Muslim's in jail for eating/drinking in public,Allahu'alim. Having fasted since the age of five in a non Muslim country even having gone to a non Muslim school where of cos knowing the nature of kids, we'll be taunted much, I can't say my fast was harder/easier there than here. However I guess this law of the land must have come about due to some reason unknown to us. So though we may not see the sense in it it still needs to be followed.