Loss of appetite?

So today I am 16 weeks. I know they say your symptoms will change all throughout your pregnancy, but it is normal for me to be losing my appetite like this. I've been lucky enough to not be sick AT ALL these 16 weeks. From about 9-13 or so weeks I was eating any and everything I seen and could not get full. But for the past few weeks I may think I'm real hungry and gonna eat a lot but then end up wasting literally half of whatever I'm eating. I thought second trimester you usually eat EVEN MORE? Is this normal?