RE: Hey, Maribeth!
Hey, Debbie!
From everything I know and can gather, neither diet nor exercise prevents the dimpling of the skin. It is due to connective tissue fibers running perpendicular to the surface of the skin--where the fibers attach to underlying tissue, they pull on the surface of the skin, making little indentations. Since there's always a bit of sub-Q fat, once the fibers form, there's always a little bit of a dented appearance. If the amount of fat in the area increases, the appearance of dimpling will, too.
Sadly, yes, it is genetic--both the tendency to form the perpendicular connective tissue fibers in the first place, and the tendency to store fat in the areas where these fibers tend to form. The fitter you are, the less dramatic the appearance, but even if your bodyfat is at a very low level, if you have a genetic predisposition to this, you will still notice dimpling.
The endermologie technique seems to help for some people. The reasons why are unclear--possibly the agressive massaging action breaks up some of the connective fibers--but it isn't permanent. For me, self tanner is a boon--brown legs don't show the lumpiness as much, IMHO.
Wish I could say that diet and exercise would get rid of it, but it doesn't, primarily because it is more a function of connective fibers than one of excess fat.
Maribeth