Awesome! Jimmy's site is being lame right now so I haven't listened yet.
I already knew about leptin resistance for the most part, although I am always revising exactly what I believe like with the carb thing. Dr. Quilt and I agree on many points although I suspect that I will learn plenty more once I listen. The thing is that leptin is an incredibly slippery issue. If someone hasn't looked deeply enough into the issue they're going to be mightily confused. Some people think that since elevated leptin produces leptin resistance, and in fact you need elevated leptin to produce leptin resistance that leptin resistance is the effect and not the cause of obesity. Compound that with the fact that adipose tissue secretes the cytokine Il-6 which increases SOCS-3 expression in the hypothalamus and causes leptin resistance, it all seems plausible. But you don't need any adipose tissue at all to elevate your leptin levels or your Il-6 or CRP. That's the thing about metabolic syndrome. Every effect in metabolic syndrome acts as a cause in worsening and perpetuating the metabolic syndrome, and one day one finds oneself at 300 pounds and is flabbergasted, hungry, and looking for answers.
The mechanisms that raise systemic inflammation in the body do not need adipose tissue or leptin resistance to arise, they can be produced by a disequilibrium of polyunsaturated fats, wheat lectins, nutrient deficiencies, endotoxemia, and plenty of other things. Inflammation will increases Il-6 and c-reactive protein and this can cause leptin resistance prior to obesity http://www.ncbi.nlm.nih.gov/pubmed/16582918 Sugar also raises leptin quite a bit, triglycerides can interfere with leptin signaling and there is just a lot of things that the paleo diet remedies that help things. I suppose the tendency to eat addictive foods to excess like Whole Health Source has been talking about plays a role, although I think that leptin resistance likely plays a role in that. They tend to be inextricable from each other so it's hard to tell.
Basically once metabolic syndrome gets a foothold we gain some weight, that fat makes things worse, and everything causes everything in a horrible downward spiral of death and doom. I'm not going to ramble about the issue here and I'm not particularly knowledgeable with the nuts and bolts, but I will say that there are definite things that people can do, but it takes some time to get everything right so they can lose weight and keep it off.