Does long distance swimming increase body fat?

Pretty much everything points to long distance swimming causing your body to "want" to have a higher bf%.  For one, adding body fat makes you more buoyant so you can spend more horizontal energy than vertical energy, therefore wasting less overall energy.  Then there's the insulation factor, as when swimming your body is actually losing heat rather than running when it is gaining heat.  I also notice pictures of top swimmers: even though they put in loads of hours of hard and extreme work, they're typically quite a bit less lean and sometimes a bit flabby. 

Here's another example:http://www.time.com/time/arts/article/0,8599,1920907,00.html
True, he is in his fifties and wasn't going for speed, but it obviously confirms that high body fat is beneficial for extremely long distance.

I know swimming burns tons of calories, but it seems as if for every calorie burned, your body makes you twice as hungry as you would be otherwise, causing forced body fat gain.