One of the most common theories is that fat distribution/location is the main factor:
If the fat is under the muscle, or interspersed between the muscle (as in "marbled" meat), supposedly it will feel hard.
If the fat is on top of the muscle (just under the skin), supposedly it will feel soft.
I think that has to be an oversimplification though, because my husband's belly was very hard when he started losing weight, and now it's very soft - so I know that the fat didn't "hop" from under his muscle to on top.
And even though my fat areas weren't "hard" like my husband, they weren't nearly as soft as they are now. I think for hubby and I it's been more a matter of "stuffing."
If you've ever made a stuffed animal, you know that if you stuff it lightly, the animal is soft, and cuddly. But if you cram in a lot more of the same stuffing, you can make an animal that is very firm. How firm, depends on the "skin" of the stuffed animal. If it's very stretchy material, it takes a lot more stuffing to make a "firm" stuffed animal (and the animal gets a lot bigger before it gets firmer). If it's a less stretchy fabric, the animal doesn't change size, it just get's firmer.
I do think skin elasticity does play a role, because I definitely feel like a teddy bear with half it's stuffing removed.
It was really frustrating at first, because my dimensions didn't change for a very long time. When I started, my bust, waist, and hips didn't get smaller, they just got softer. In fact, I started taking two measurements - the "regular" bust, waist, and hip measurements - and the "tightest I could pull the tape" measurements.
For a long time, the regular measurements didn't change, but the "tightest" measurements were getting smaller. So naked, I looked the same, but I was squishier and could smush myself into a smaller size.
Last edited by kaplods; 12-12-2011 at 06:26 PM.