You can make explicit the full meaning of this sentence. Alternate translation: "Do not undo what God has done for a fellow believer just because you want to eat a certain kind of food" (See: [[rc://en/ta/man/translate/figs-explicit]])
Here anything that "causes someone to stumble" means it causes a weaker brother to do something that is against his conscience. Alternate translation: "but it would be a sin for someone to eat food, which another brother thinks is wrong to eat, if by eating this causes the weaker brother to do something that is against his conscience" (See: [[rc://en/ta/man/translate/figs-explicit]])