Dave answered a post I made wondering about effects of types of fat. Swapping fat sources for somebody eating around 30 percent fat is a bit different than eating those same proportions of fats at a higher or lower total fat intake. If you take omega 6 fatty acids, for instance--there might be threshold effects for that particular fat in particular. Take a fat source that will leave you essential fatty acid deficient at 100 grams of intake, double intake--and you might get sufficient essential fatty acids, that could have profound effects.
DaveKeto said;
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Yes, my plurality of fat is saturated (probably around 40%), although I did do an 11 day experiment where I swapped it with mono and slightly higher poly. The results weren’t too significantly different. Plus, I felt generally puny and tired throughout. Not sure why.
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There's still the question of type of fat, whether you get 40 percent of dietary fat from coconut, butter, lard, or other sources makes a big difference to the particular free fatty acids you're taking in, palmitic vs. stearic is a big deal, same is true of various poly- and mono- unsaturated fatty acids. Swapping with mono and slightly higher poly--if an effect were had from his usual to appetite ketogenic diet being lower in, say, linoleic acid, then changing to a diet where linoleic acid was increased by sheer bulk of fat in the diet, it's possible that he had already reached the point of diminished returns for increasing linoleic acid vs. ldl cholesterol levels, with raising it slightly at that point having little obvious effect.
http://www.free-workout-plans-for-b...carb-diets.html
This person looks at four studies with effects of a ketogenic diet on cholesterol, not really comprehensive. But interesting that a study from the 70's on the Stillman diet showed 12 dieters changes in cholesterol, they typify the diet as high in animal fat and protein, we know here that it would fall in what Dave would probably call a lower fat, higher protein low carb diet, has this to say;
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The serum cholesterol increased in every case, from an average base line of 215 mg/100 ml to 248 mg/100 ml during the diet
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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/
Then there's this study.
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To determine the effects of a 24-week ketogenic diet (consisting of 30 g carbohydrate, 1 g/kg body weight protein, 20% saturated fat, and 80% polyunsaturated and monounsaturated fat) in obese patients.
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Cholesterol and ldl cholesterol went down significantly here, it's hard to say by how much, or how much fat was eaten, how much of it polyunsaturated vs. monounsaturated--but the authors do go to some lengths to praise the wonders of polyunsaturated fat-based ketogenic diets in the preamble. Type of fat, sheer amount of fat, mixture of both? I think we need more studies/n=1's to parse this out. The difference between an approach that stressed protein vs. one with a greater emphasis on added fat (but polyunsaturated) is interesting, the second study gives an average change in cholesterol, but every one of 12 subjects on the one approach experiencing an increase in cholesterol, vs. 83 subjects on average having reduced cholesterol doesn't sound like a chance occurrence.