jay wrote:

I had been eating a lo-carb, lo-protein, hi-fat diet (ie approx 7%,
7%, 85%).

Generally grams matter a lot more than percent. Guessing 2000 calories
for the day that would be 28 grams of carb, low but not extremely low,
and 28 grams of protein, extremely low. Guessing at 1000 calories
you're very close to what Atkins called the fat fast.

When I lower the carbs even further, I get a thermogenic
effect. How/why does it occur? Is it related to glucagon?

I take it you mean you feel more heat coming out of your body and/or
when you take your body temperature it is at least a degree warmer than
normal? I get that as an intolerance reaction to wheat, clearly not the
same effect as what you're seeing. ;^) I also got that effect for
something like days 2, 3, 4 of my first Induction. I took it as a sign
that my metabolism had increased. Increased metabolism equals more fuel
burned and that's generally a good thing when dieting.

Insulin pushes fat into storage. In that simple sense higher insulin
tends to mean lower metabolic rate. Actually it's one small effect
among many and the net effect on metabolic rate isn't large. But below
some point less carb no longer means less insulin no longer means less
pressure on fat to move into storage. Once fat is flowing out of
storage further lowering carbs stops helping loss.

Glucagon pulls fat out of storage. In that simple sense higher glucagon
tends to mean higher metabolic rate. That would be the thermogenic
effect you see. Glucagon is released as an indirect effect from dietary
fat so it does not track as simply as the linkage between dietary carbs
and insulin. The simple view is more dietary fat triggers more glucagon
triggers more fat pulled out of storage - This is why the obvious
approach of lowering fat while low carbing does not work. But it's
fairly easy to overwhelm this pattern of eating more dietary fat to lose
more stored fat.

What are the requisites to create the themogenic effect?

High fat relative to both carb and protein intake. It's why the fat
fast is so effective. But that effect is temporary. It's why the fat
fast is limited to two weeks and why the basic core Atkins plan
Induction is two weeks long. As far as I can tell the thermogenic
effect is a metabolic reaction to "switching" to a fat burning
metabolism but not to "being" in a fat buring metabolism. That's my
hypothesis. Experiment all you like to confirm or falsify the
hypothesis.

So here's what I think is happening - Change matters. Fat to carb plus
protein matters. The thermogenic effect happens when you change to a
higher fat to lower carb plus protein diet. The thermogenic effect goes
away when the body adjusts to its current intake. I think that's why I
got the effect for a few days early in Induction. I think that's why
you got the effect when you changed your ratios.

Where in the body is it
occurring primarily (ie liver, muscles, adipose)?

It being a matter of hormone levels I don't think it can be isolated to
specific organs.

Is this due to uncoupling in the mitos?

I don't know what that means.

If I lower the protein and up the fat, will this affect go away?

Do you want to deliberately pursue the effect because it means you are
burning more stored fat faster? Or do you want to avoid the effect
because it's wierd and a bit uncomfortable?

I think you can avoid the effect by staying at a specific ratio for at
least a week because of the body adjusts. I think you can turn off the
effect by going to higher carb and/or protein levels then reducing fat
for the same total calories.

If you want to pursue the effect I think it takes a cycle. Consider
that body builders sometimes do very low carb during the week, very low
fat during the weekend. That's one type of cycle. I suggest a half
week or a week at your extreme plan that's near a fat fat. Alternate
that with a half week or a week that's higher in protein and/or carbs.
The cycle will move out of the thermogenic range then back into it.
Each time the body adjusts to turn off the thermogenic effect it will be
pulled out of the themogenic range, then given time to adjust to a new
intake level. Then back into the thermogenic range.

It would be a lot of work. You're already doing an extreme plan that's
a lot of work.