Recently, I'm always hungry.?

I used to be obese but I lost most of the weight and I'm at a normal BMI now and I still workout, but it seems like no matter what I eat, I'm always hungry about 45 mins later. I lost close to 100 lbs and in that time where I worked out everyday to lose the weight, I don't recall ever being hungry during my weight loss period. I actually eat a lot more and I eat a lot healthier now, and I'm still hungry. At Lonestar Steakhouse, they have a 20oz Porterhouse and the waitress said if this doesn't fill me up then something is wrong, and it seriously doesn't fill me up whenever I eat it. I don't do crazy workouts either, I just job for about mins and I walk around my town about an hour a day, and I used to lift weights over the winter, but I don't lift weights now. Do you think my metabolism has just rose like crazy and I need a lot of food now, more than normal people because of exercising for 2 years (but like I said, I didn't do any hardcore training, just normal stuff) or is there some health issue that can explain why I'm never satisfied when I eat and I'm always hungry?