I've been experimenting with pork rinds to see what effect, if any, they have on my weight setpoint. I was pretty consistently at 155-159 eating 150-200g of carbs (usually yams and sweet potatoes, some parsnips, and lentils).
I started eating 1-2 bags per day of Frito Lay's Baken-ETS. One bag of Baken-ETS has 800 calories: 0g net carbs, 50g fat (25g SAFa, probably 20g MUFA and 5g PUFA), 70g protein (surprisingly high), and 3,000mg sodium. That's about 60% fat and 40% protein, despite the nutrition label indicating 45% calories from fat.
I soon found these pork rinds to be irresistible. Whereas I would find my bone broth soup to be very filling, I couldn't get enough of these pork rinds. I gained 5 lbs. after a week. My weight range went up to 160-165 and the fat accumulated around my abdominal area, tightening my pants.
First, pork rinds aren't really an ideal Paleo snack: even though there aren't any artificial ingredients, they're fried in grease with a ton of sodium. It would have been very unusual for any ancestral diet to have included fried pork skins (or fried anything, for that matter). But they're not supposed to be glycemic: there are no carbs nor sugar and there should be no insulin response. Then, why the irresistibility?
Perhaps Stephan Guyenet and Seth Roberts are right about food reward and hyperpalatability. Even though many, irresistible snacks (like pop tarts, candy bars, soft drinks, Doritos, and pretzels) are full of sugar, salt, HFCS, and grease, they're irresistible not due to insulin elevation but due to something else that's triggering the brain. In other words, they're "hyperpalatable."
What is meant by hyperpalatability? Seth Roberts explains this best in his interview with Jimmy Moore.
Seth talks about having sugar water or olive oil with water and how this can lead to weight loss because of the monotony of eating something bland. It's not really sugar or carbs; it's the blandness of our ancestral dishes which does not stimulate the pleasure centers of our brains -- where eating becomes necessary to live, not the other way around. Foodies need not apply; eatings is for fuel.
I experienced something similar: when I leaned out to about 152 lbs. (my all time lowest weight), I was mainly eating 1 meal a day (breakfast) plus boiled yams and green tea. The monotony of eating yams and green tea probably resulted in lower overall calories; I never overate and never had any cravings for anything else. Even though yams are moderately glycemic, the monotony of more yams and green tea prevented them from being "hyperpalatable."
So what is the breakthrough here? If you can point to an all-fat/protein snack that's hyperpalatable, doesn't that lessen the carb/insulin theory of obesity? Some people point to nuts. I'm sorry, but I've never been able to overeat raw nuts that have no added sugar nor salt (that includes macadamia nuts). In fact, I used to conduct appetite suppression experiments with these types of nuts:
These redskin Spanish peanuts are incredibly filling, even though they have added salt (sea salt) and grease (sodium and cottonseed oil). Is it the fiber in the red skin? Don't think so, there's very few. Protein? Protein is only 17% of total calories, while fat is 78%. Sugar is endogenous and only 1g.
In other words, hyperpalatability seems to stem from something else. Seth seems to think it's sugar/salt/grease and/or spices. Plus the smell. I think he's correct. But there seems to be another dimension: the texture, shape, and amorphous nature of these manufactured comfort foods. Our ancestors never encountered something like pork rinds or Doritos before. Eating anything required work: shelling, cleaning, removing the skin, sorting, fermenting, removing the debris. To eat pork rinds, you just have to open the bag and the pieces literally melt in your mouth. And the random, amorphous shape of these rinds seems to convey something "subliminiminal", as Dubya would put it.
Plus the sound of crunching these rinds. Those who do not believe that Rice Krispies are appetizing (my favorite cereal when growing up) because of Snap, Crackle, and Pop do not understand the susceptibility of human nature -- it's the admixture of olfactory, auditory and tactile sensations which enhances the overall palatability of something you eat, the overall experience.
This doesn't mean that the carb/insulin theory is wrong; I know exactly how appetizing a hoagie sandwich or a pasta dish is. Hyperpalatability simply adds a layer to the phenomenon of obesity from another angle. For example, if I added a bag or 2 of pork rinds when very-low-carbing, would I have gained weight? The answer is probably yes, but not as much. Eating 150-200g of safe starch carbs may have made me an easy target for pork rind addiction, if they resulted in chronic and meaningful insulin elevation.
Also, there is more to it than just added ingredients such as sugar, salt, and grease, which induce powerful food cravings when mixed in right doses. Robert Lustig points out that soft drinks generate sales by mixing sugar (HFCS) with salt (Na), making you thirsty for more. Seth points to your nostrils.
But it's not that simple. There's more to it than meets the nose. It's the eyes and ears, too. And throw in your unconscious. Obesity is a phenomenon that defies consensus. It's not that it's "complex"; it's too subjective. Get used to it: we're not getting any closer to solving obesity. It will remain a riddle.