What do you guys eat for lunch ?

I know it seems like such a specific question... But one of the symptoms that makes my life difficult (a lot) is the fatigue after eating lunch. (I will be tired after dinner too but at least I can take it easy). After lunch, I'm at work, and all I wanna do is sleep. My eyes are closing, I'm having a hard time concentrating.... So what do you guys eat for lunch to avoid the fatigue?