Low Cal Adult Beverages

Hello All! I am going to Vegas at the end of this week, I am going to want to consume some adult beverages. Is there a low cal option?I usually like beer (budlight), malibu and pineapple, and anything fruity! I cannot drink wine as it gives me a killer headache.

I know some of you will say just don't drink.. but it is my first time in Vegas and I want to enjoy it!

Any helpful advice will be greatly appreciated!