Weight / Fat loss

Not necessarily. Overconsumption of "rich" (fatty) foods will also lead to it, i.e., gout. But I'm sure you have to do some pretty crap stuff or have a genetic predisposition to it to get it young. I think what I was mentioning early, cos I always go off half-cocked, is that it seems to me that if you eliminate carbs and eat a high-fat diet, this would likely lead to this sort of problem. But then, I shouldn't talk about things I'm not 100% sure on. THis is just stuff half-remembered from school 6 years ago.

Exactly this type of diet is becoming very popular. (look at fads like paleo diet)
People like inuits have traditionally eaten purely this type of diet, just seals and a few fish.

Just fat & protein. Apparantly you get used to it.