if I live with non-Jewish people can I eat food they prepare during shabat?

Your question omits the crucial point -- "can I eat food they prepare during shabat?" FOR WHOM? For whom did they prepare this food?

For themselves, and you come along (and it's completely kosher etc.), and they wish out of the goodness of their hearts, and without prearrangement of any sort, and no prior discussion with you, to share it with you? This would seem to be permissible: "If a non-Jew heats food or water on Shabbat for himself or for other non-Jews, a Jew may use the water and eat the food." https://outorah.org/p/41419/

But did you ask them to prepare it, or hint that they should prepare it, or say you were hungry, or did they add extra portions to the pot for you because they knew you would be coming along and wanting something to eat, so they cooked extra, more than they needed for themselves and their non-Jewish guests? Then no, you cannot eat the food they cooked on shabbat.

Of course, you say "prepared" -- so that is completely ambiguous. "Prepared" could be (i) making a salad by mixing fruits or veggies, (ii) creating a dish from raw ingredients and cooking it until it is "well done,", (iii) reheating an already cooked dished that has been cooked once and cooled off, (iv) reboiling something that has been previously boiled; or (v) going into the frig to make a peanut butter and jelly sandwich. All raise different questions, and so, to be honest, your question is meaningless.

Better (i) be specific and (ii) ask a rabbi.