I can't speak for others and I'm certainly not one of the hardest training people here, but I've lost 35 pounds since September. That's an average of about 5 pounds a month or a bit more than 1 pound a week -- the exact amount recommended for permanent weight loss.

If you're interested more in the psychology, check out the book "Mindless Eating" by Brian Wansink, who studies food psychology. Basically he says people drastically overcompensate for the calories they burn through exercise. He's also the guy who studied how much people eat when they have bottomless soup bowls and how the size of the popcorn bag influences how much people will eat.

One risk of exercise is that some people subsequently overeat, thinking they are compensating for the calories they burned. They almost always overeat. The key to Mindless Eating isn’t in necessarily giving up all the foods a person loves. It’s being more naturally mindful (not obsessively mindful) as to some of the tradeoffs required.

In one study we’ve done, we found that listing the number of miles a person would have to walk if they consumed a 300 calorie bag of granola lead them to eat less than if we just had the calorie count in it. For many people, it’s not necessary that they eliminate all "bad” food, just that they trim it down.

The key to Mindless Eating, is that you can set up some of your own rules and trade-offs so nothing is off-limits as long as you see the bigger picture.
Here's a NY Times article about the same person.