I got food poisoning from yesterday's sashimi.
食あたり is the everyday term specifically for mild food poisoning, whereas 中毒 covers poisoning from any toxin, not just food, and sounds more clinical.
Standard kanji spelling for food poisoning.
Alternate kanji spelling using 当.
Rare kanji spelling using 中.
Compound of 食 (shoku, 'eating') and あたり (atari, 'hit' or 'strike'), literally meaning 'struck by food'.