Before us is Mishnah 1 of chapter 4 of Maseches Kesubos. The Mishnah opens: "Ein bein hamudar hana'ah mechaveiro l'mudar heimenu ma'achal" - there is no difference between someone who is forbidden to derive any benefit at all from his fellow and someone who vowed only not to benefit from his fellow's food, "ela derisas haregel v'chelim she'ein osin bahen ochel nefesh".
The two differences between one forbidden all benefit and one forbidden benefit from food:
"Derisas haregel" - one who is forbidden all benefit may not even set foot in or pass through his fellow's field or property, since he may not derive any benefit from him whatsoever. But for someone who vowed only not to benefit from his food, passage through his fellow's property is not included in his vow.
"Kelim she'ein osin bahen ochel nefesh" - borrowing utensils that are not used for preparing food is forbidden to one who is forbidden all benefit, whereas for someone who vowed only not to derive benefit from food, these utensils are not included in his prohibition.
"Hamudar ma'achal mechaveiro lo yash'ilenu":
Someone who vowed not to benefit from his fellow's food may not borrow from him:
A sifter.
A sieve - a utensil similar to a sifter.
A millstone - a grinding stone or mill.
An oven.
All of these are utensils used for preparing food, and therefore someone who is forbidden to benefit from his fellow's food may not use them.
"Aval mash'il lo chaluk":
On the other hand, one may lend the following items to someone who is forbidden to derive benefit from food:
A chaluk - a tunic.
A ring.
A tallis.
Nezamim - earrings.
"V'chol davar she'ein osin bo ochel nefesh" - any item that is not used for preparing food.
The exception - a place where such items are rented out:
Even with these items a problem can arise: in a place where it is customary to rent out utensils of this sort for payment, borrowing them is forbidden even to someone who vowed only not to benefit from food. The reason: the money the borrower would have had to spend on renting them is now saved for him, and that saved money can be used to buy food. So even though the benefit is indirect, it ultimately counts as benefit from food, and it is therefore forbidden.
The only time one who is under such a vow may borrow items unrelated to food is when they carry no monetary benefit at all, since any monetary benefit can end up turning into a benefit of food.