General

I don't think that it's genetic. Everyone in my family seems freaked out by weight.

That isn't necessarilly indicative of it not being a genetic trait, if the codon/gene/allele was recessive it could be passed on unseen for generations before finally hooking up with another recessive and surfacing. That's not to say that I think that it's genetic per-se but I certainly feel that genes play a role in it.

Logically thinking it makes sense, seeing as up to about 400 years ago being able to store energy for a "rainy day" was a very beneficial trait. And it goes without saying that, in general *especially in those days*, such a trait would be sought after.

I remember this discussion brought up once but I don't remember where.

One good argument I heard was that it's a primitive trait embedded in our genes (much like how Geese fly south for the winter). In primitive culture, males were the hunters bringing food back for their mates. Without written or spoken language, you would have to rely on visual cues. So by visually seeing your mate larger you would know they were well fed and that you were doing your job. Same sort of reasoning for why men are attracted to larger breasts or women with curves. It harks back to when those traits were important for selecting a mate.

Using same argument, explanations for wanting your mate larger or even yourself larger would be a way to show your own dominance amongst the pack. For instance, a larger 200 pound male would appear dominant over a group of 140 pound men. Or even back to a time where food was scarce so you would eat as much as you could in case you can't find anything to eat for a while. Because humans have progressed past this sort of thing, these primitive traits could just be expressing themselves through your own sexuality.

I agree with everything you say except that an allele is a pair of genes, an allele is a single gene which hooks up with it's homologue during sexual reproduction; forming a homologus pair.

You are right though, what I was thinking of were genotypic/phenotypic ratios, but only so far as to explain that a recessive allele/trait can go generations without being expressed.

I don't think its genetic. I think it's largely environmental. At least based on my own experiences, I've shifted significantly from being mostly interested in thin girls as a kid to being mostly interested in fat girls, and I think can point to specific experiences I've had and people I've met who I think prompted my tastes to slowly shift. My first middle school dance partner, my first high school girlfriend, my first long-term relationship come to mind.

I do think genetics influences environmental outcomes. For example, if many people in a family are fat, which is influenced by genetics, someone growing up in that family is much more likely to see fat people as desirable.

I have no idea where I got it from. There aren't many fat people in my family, and most of them are dieters and lipophobes. But if it's not in my genetics, then where in my environment did it come from? I saw some fat people in my youth, I'm sure, but they were never presented to me in any particularly positive light. It seems there had to be something already in me that was only responding to the fat people around me, causing me to judge that I wanted to be like them. How does a six year-old child decide to gain weight? Only that it never felt like deciding, it's just how life felt to me.