Pregnancy hunger!!!!

Taylor
I'm in my second trimester and I find myself just wanting to constantly eat!! I was told I only need about 300 extra calories a day. I don't want to over eat and gain a lot of weight, but if I'm feeling hungry should I just eat? Or try to deter from it? 
Again, I don't want to gain a lot of weight. But want to make sure my baby and I are both healthy.