Brian, I agree 100%
For short term trip, losing a few pounds is OK. Most of us can afford it. I can for sure!
For longer tru hikes, I find that two to three weeks in I start eating an extra 5 or 6 ounces. For example, I will make a stew that has about 1500-1700C for supper. Three -4 weeks, I add a packet of rice/noodle sides, around another 1000 calories. 6-8 weeks in, I will add a couple candy bars, too.
I started with 1.2pounds, ended with about 2 pounds. But, I am older with a slow metabolism. Someone younger, with a faster metabolism will need more to start and add more.
I believe Mike Clelland wrote about this in his book, also.
Turning in to the proverbial "garbage can," when you finish...well that is a differnt problem...ha, ha... Anyway, my 2 cents...