Yes sugar, and high fats, may impact foot pain.

Sugar has two ways of doing this IMO. One is stimulating insulin release which causes the excess sugar to be stored.This results in a crash of the blood sugar quickly which starves the nerves in the periphery. The other effect is to feed any Candida that may be in the bowel. This yeast lives off sugar and releases toxic by products into the body...aldehydes, which then cause nerve symptoms.

There is also a metabolic cycle in the liver, involving fructose, (1/2 of sucrose is fructose) This video explains how fructose is now being considered a "toxin" to our bodies. This is a medical lecture from San Francisco, and very revealing. It is very long, but very interesting. The liver metabolism of fructose is about in the middle:

http://www.youtube.com/watch?v=dBnniua6-oM

Secondly, high fat intake (like from a large serving of ice cream) or sour cream, mayo, etc, can make the blood more viscous. It has been medically reported that after a high fat meal, the blood becomes very thick, and this can cause heart attacks or strokes. Moderate fat intake does not do this.
The heavy fat intake meal, therefore, will make it harder for the blood to get thru the tiny blood vessels in the hands and feet, and make fluid back up, and affect the nerves that way. If a person has any globulin disorder, it will make that thicker blood much worse.

People can be intolerant of gluten, soy, casein (dairy), and this may release immune antibodies which attack the nerves.

So yes, food intake, type and quantity may impact PN significantly.