It's since gotten off-track a bit, but as far as weight effecting ticklishness, here are my thoughts, and please, if anyone with more anatomical expertise can correct me or better articulate my thoughts, you are welcome to do so. I am no anatomical genius, but can surmise based on experience:
There are two types of tickling:
A.) The kind that is designed for stimulating nerve endings (light touches, feathers, raking with fingers and fingernails, "raspberries", etc.),
B.) ...and the kind designed for stimulating nerve tracts (kneading, squeezing and other pressure application techniques).
Type A requires friction over the surface of the skin. The fingertips, nails, feathers, etc., all move over the skin's surface, stimulating the nerve endings.
Type B does not require friction over the skin's surface (the place of contact between finger and skin may remain constant), but does require pressure and/or friction over the nerve tract, through the flesh by way of kneading or squeezing.
Therefore, here are your issues pertaining to weight:
1.) Increased body fat may allow a layer of insulation in some areas between surface of the skin and nerve tract, such that Type B tickling may be somewhat less stimulating -- it being slightly harder to stimulate the nerve tract (though probably, not by much). You may notice that fat accumulates less at vital areas that are rich in nerve endings and their related tracts (mostly at joints and soft places with arteries -- increased sensitivity means their owners will keep those places better protected), so if you're heavier and feeling less ticklish, be sure your 'ler exploits these areas to give you what you need.
2.) Taut flesh is more sensitive than loose flesh. You may notice that to get the best reaction out of a 'lee being tickled on the feet, the 'ler will stretch them back, making the skin tight. This allows for greater movement of the stimuli over the skin's surface for Type A tickling. So, if you've added a significant amount of weight and lost it, the looseness of the flesh may make Type A tickling less effective. But Type A tickling is still quite effective on someone who has recently added weight or simply maintained their weight, as it keeps the skin tight.
Type A can also still be somewhat effective with loose flesh, provided you use the right technique -- namely with something that won't "draw" the loose flesh with it, as doing so would impede the friction over the skin's surface -- perhaps brushes or feathers.
3.) Circulation is better when you are healthy. Increasing fat puts added demands on the heart, increases blood pressure, and decreases capillary efficiency. Capillary efficiency is key to Type A tickling, because it provides the nerve endings with oxygen to function at their peak. Someone else mentioned capillaries and drinking. Again, alcohol dilates capillaries, allowing the passage of more blood, more oxygen, and so, nerve endings work better and become more sensitive.
Some of the people with the least body fat are some of the most ticklish because the nerve tracts are so close to the skin's surface, that a vigorous Type A tickle can also work as a mild Type B tickle, stimulating nerve endings and tracts efficiently, simultaneously, and devastatingly.
Stay healthy, stay sensitive, stay ticklish.
All the best, kids!
None of them did the backhoe thing. I was talking about friends and stuff who in a moment of teasing started in and just dug their fingers in like shovels.
