I spoke with an "educated" nutritionist about this very topic, even brought up the 300 pound woman angle, and this is what she told me...I am paraphrasing here.
No adult person, unless they are super athletes should eat more than 2000 per day. If you are making healthy choices in your eating, you should actually have a difficult time reaching 2000 calories. It is only eating the high fat, high calorie, high sugar foods that will make reaching 2000 calories easy. If you fill your diet full of veggies, fruits, whole grain products, low fat proteins, nuts, beans and low fat dairy products, you will be very satifisfied and be challenged to meet 2000 calories.
There is her advice in a nutshell. She also gave me crap for eating too few calories!! She says I should eat 1600, when I am eating between 1200 - 1400!! She says I am going to become exhausted both mentally and physically if I don't up my calorie intake AND my body will start burning muscle mass to make up for the deficit!!
I don't know what to make of that.