Sure, and I didn't mean to come across as obtuse, my point was that it's hard to find truly culture-insensitive aspects of the human experience.
Even the basics like our tastes in food, and what traits we find physically attractive, are steered by culture. You're right of course that ultimately we're wired to enjoy sugar, fat, and salt, in a way that works against our health when they are available in effectively limitless quantities.
I don't agree with Most of our behaviour is based on instinct. We allow perfect strangers into our homes to fix the plumbing. (Bruce Schneier wrote a great book about this kind of trust. [0]) A baby can learn to enjoy the company of a Malamute. Even our instinct to avoid being eaten by wolves, seems to be negotiable.
> changes in availability of unhealthy food are needed to improve the population health.
Agreed.