Malvineous:
Here's my theory. From what I've read, the way memory works in your brain is by creating a neural pathway for the event. The more your brain travels that neural pathway (the more you think about it), the stronger it gets, and the easier to access next time. This is why people can easily forget what they had for breakfast yesterday, but they still remember things they had to memorize in school when they were 10 years old, even if it's knowledge that they don't find useful in their daily lives. In the first example, they only thought about it while it was happening and never returned to that neural pathway, whereas in the second, they had to think about it a lot, so they permanently made that memory strong in their minds.
I think fetishes work in a similar way. They create a neural pathway of a trigger, like 'fat = arousal', and the more that gets triggered in their brains, the stronger that connection becomes. Your interest in it may come and go (just like you can go years without thinking about a specific memory), but that connection is permanent and there's no way to weaken it. I think if you don't want to have certain fetishes, your best bet is to not expose your brain to them in the first place.
X_Larsson:
Mostly yes, but I have a bit of objection here. As western society is now (like so many other civilisations before us!) is now in a stage of moral decline, hedonism and depravation, we see the same pattern happen as in the roman empire, or the greek reign. This means a worsening normalisation of fetishes and kinks, which in turn means an ever growing exposure to normally repulsive, or at least unusual, scenarios and relations.
Compare the post 2015 world to what life was like in 1985, heck even in 1995! We did not have bearded "women" winning the Eurovision Song Contest, pride parades everywhere, SLEWS of mainstream movies about gay people, a massive promotion of body mutilation, BDSM, tattoos etc. Don't get me started on the pronounce debacle...
Now, everyone is just supposed to "accept" and "support" all these (objectively) rare manifestations, and they are given a huge display, front and center in so many places.
However, all the adult people in my social and professional circles, myself included, remain as disinterested and/or put off by this as we ever wore, in spite of the massive exposure.
So in some ways, we are not always becoming curious about, or more prone to deviations, even if we are repeatedly exposed to them in many different situations.
For me personally, the way feedism manifests, as well as what constitutes an ideal feeder/feedee couple relationship, has not really changed even after decades. That is also what other male feeders have stated about themselves.
However, like Malvineous says, it is not uncommon that people with certain fetishes add more fetishes to their sexual deisres, as they grow older / get more experienced in their previous fetishes.
For me, this is another indication that feedism itself is not a fetish (manifestation of sexual desire in an object, ie shoes or BDSM leather outfit), but rather a sexual identity, like homosexuality.
Who hurt you?