Okay, the user wants me to translate "unsaturated fat" into Simplified Chinese. Let me check if the term is already in Simplified Chinese. The original term is in English, so I need to translate it.
First, I recall that "unsaturated fat" refers to fats that have double bonds in their chemical structure. In Chinese, the term for unsaturated fat is "不饱和脂肪". Let me confirm that. Yes, "不饱和" means unsaturated, and "脂肪" is fat.
I should make sure there's no alternative translation. Sometimes terms can have different translations, but in this case, "不饱和脂肪" is the standard term used in nutrition and chemistry contexts.
Also, the user specified to provide only the translation without any explanations. So my response should just be the translated term. No need to add anything else.
Double-checking the rules: translate into Simplified Chinese, leave as is if already in Simplified, and only output the translation. Since the input was English, translating to Simplified Chinese is correct.