Swimming Questions

I've been swimming for a month or so and have not lost any weight. I've just finished a year so I'm not too worried about that. The question is my kids also swim and seem to hold on to their weight. They swim from April to July 1 hr 4-5days / week.

So here are my questions:

1) Is there some reason that you might not lose weight when swimming vs something like the elliptical?

2) Why when doing any other type of aerobic activity I'm not hungry for sometime after and when you swim you are ravishingly hungry?

I read an article probably 4 years ago where it was talking about the fat percentages of olympic athletes.  Now barring the wrestlers and shot putters etc, they found that the swimmers had higher body fat content.  You would never know it to look at them, but that's what the numbers showed when they tested them.

I tried to find that article, but was not able to, but this one is similar
http://www.sportsci.org/news/compeat/fat.html

And of course, I found one that said exactly the opposite.
http://findarticles.com/p/articles/mi_qa3871/is_199807/ai_n8 795819

There are quite a few articles out there about the subject.  Most of them seemed to say that the long distance endurance athletes were the ones with the lowest body fat.

I have noticed that swimming is harder now with less body weight.  I guess I don't float as well.

The first article I posted has a section specifically talking about the hunger issue you posed in question 2

Good luck sifting though the data.

Scott