js290:

I believe the pro-inflammatory effects of n-6 on the eicosanoid system occur when it becomes incorporated into cell membranes and other tissues...so Rosedale is right in that case AFAIK. 

The problem, of course, is that linoleic acid (the only dietarily significant n-6 fat) is prone to oxidation and glycation, it's trickier to burn due to all the double bonds that must be saturated before conversion to acetyl-CoAs -- and as Petro @ Hyperlipid has been exploring, it's likely a strong fuel for cancer and adiposity. So it's probably best to minimize intake: since you can't avoid a couple % in the diet, that will maximize the chance that it does get burned.

Death Yoga:

Congratulations on your progress!

The powdered food paper was great, and I'm indebted to Kindke for bringing it to my attention.

There are indeed some robust trends in these studies: more processed = more fattening per "calorie", less protein = more fattening per "calorie"...and that's independent of their effects on hunger, which are usually synergistic to those factors, since processing usually strips out nutrients.

And this is the main reason I take issue with the CICO zealots: they don't even believe their own propaganda!  None of them ever says "My calculator says I can eat 1800 kcal today...I'll take that as three Snickers and a 2-liter Coke."

Paul:

The honey results surprised me, too: there isn't a lot in honey besides simple sugars, but apparently it's enough to make a difference...at least in rats.  I wish I had the fulltext!

Peter:

While I agree that sugar seems to make diets more fattening, the laws of thermodynamics absolutely still apply.

However, as has been amply demonstrated in this series, there are many other ways to produce "calories out" besides weight gain.  I explained the possible mechanisms behind them in Part I...and so do people like Lyle McDonald, who helpfully provides the equation:

Energy In (corrected for digestion) = (BMR/RMR + TEF + TEA + SPA/NEAT) + Change in Body Stores

However, the "Eat Less Move More...it's that simple!" crowd removes all the interesting terms from this equation:

• (corrected for digestion)
• BMR/RMR
• TEF
• TEA
• SPA/NEAT

...terms which themselves are catchalls (e.g. "thermic effect of food") for empirically measured numbers which no one really understands.  That's why CICO/ELMM is not useful in practice:

• It ignores all of these terms, which I've proven over the last five installments to be significant
• It ignores the fact that we can't possibly estimate food intake accurately enough to hit our targets, even if we could account for all these terms
• It ignores the effect of different foods on appetite -- which statistically overwhelms all attempts to count calories

JS

Valerie:

"If so, what about the remaining 12%?"

According to the ingredients: cellulose (fiber), water, salt, vitamins and supplements.  See the supplementary figures.

"Isn't it 4 cal/g for both sugar and protein?"

That's a close approximation, but protein is actually slightly under 4 kcal/gram (and it depends on the proportion of amino acids) and carbohydrate slightly over.  (Also, the energy value of protein can range all the way down to negative: read Part I.)

"Still in the first study, there was a clear difference in weight gain, yet no difference in energy expenditure. Huh? Seems to me like calories disappeared...When you write that the study measured energy expenditure and oxygen consumption, do you mean, basically, "calories out"?"

The laws of conservation of energy still hold.  We know that the energy was not stored as fat or lean mass; we know that it wasn't pooped out in feces; we know that it wasn't dissipated as extra running-around; and we know that it didn't cause the mice to consume dramatically more oxygen.  Thus, it was most likely dissipated as heat -- whether by futile cycling, peroxisomal degradation, and/or some other mechanism.  (I don't know enough to speculate which.)

JS

Death Yoga:

What proportion of calories from carbs?  If you're only eating 15-20% max, and you're working out intensely, you can usually get enough nutrition from the 80% protein, fat, and green veggies (if you eat real food) so that the carbs can be junk and it doesn't matter much.

However, if the IIFYMs are talking about a high-carb diet, then I suspect they're far from optimal: in addition to the nutritional issues, fructose, glucose, and lactose aren't equivalent.  Then there is the GI difference.  And if they're talking about a 30% micellar casein/30% seed oil/40% Mexican Coke diet, well, that's almost exactly the diet scientists use to make mice and rats obese as rapidly as possible...

I haven't watched the video since it's 30 minutes, but I'm familiar with the idea: you need to refeed periodically to fool your body into thinking it's not starving so that it'll continue to let go of fat stores.  Sub-10% bodyfat land is where you're fighting uphill against leptin dynamics and a host of other issues.

Alex:

There's snake oil at every extreme -- including the HCLF/raw vegan extreme, where only fat can make you fat, as well as the keto extreme, where only carbs can make you fat.

Unfortunately the ELMM/"calories are all that matter" extreme is mainstream nutritional dogma at this point, whereas the other beliefs are small fringes.

My point is simple: Calories count -- but they don't all count the same.  This is just one reason why paying attention to the type and quality of the "calories" you eat is likely to be far more productive than simply trying to reduce their quantity.  (Other reasons include their differing effects on hunger and satiety, which is usually the biggest factor, and the awkward fact from Part V that we can't estimate our intake accurately enough to get results consistent with "calorie math".)

grinch:

I find it unlikely that mice and rats (particularly rats) can produce wildly varying results, but humans are perfect bomb calorimeters. 

Now, I haven't gone through every study AC cites (I assume you're quoting him because of your use of his trademark phrase "tightly controlled metabolic ward studies"), but from what I recall, none of the studies in question looked at situations similar to the mouse/rat studies I've quoted, e.g. powdered vs. regular chow (Part II), a diet of 2/3 coconut oil (Part III), swapping SFA for n-6 PUFA (this part)...and if anyone wants to dispute the higher TEF of protein, feel free to fight with the 34 citations in Bosse and Dixon 2012, from Part IV.  (I don't think AC disputes this...just whether the effect is large enough to be important in practice.)

Nor do I recall any of those studies dealing with situations similar to those from the human studies I quoted, such as the "carbs at dinner" study from Part II, or the diet of 1/2 almonds (Part III)...the second of which counts as a "metabolic ward" study, since the patients were inpatients at a hospital!  ("Metabolic ward" just means "the part of the hospital where they keep people in metabolism studies"...it's not a magical guarantee that no one cheats.)

Finally, I note that there are studies showing dramatically different effects from different macros, e.g. Kekwick and Pawan...which AC finds his own reasons to not include in his dataset.

Please note: given what I know at this time, I think the effect of different foods on hunger and appetite is likely to be more important in practice than their divergence from the Atwater factors.  However, the multi-decade emphasis on "calories"/ELMM has proven to be remarkably ineffective, and I prefer to let reality guide me towards my hypotheses.  For instance, did America experience a massive failure of willpower contemporaneous with the Reagan inauguration?  I see no evidence for that.

JS

Death Yoga:

"Some people swear by IIFYM, but as far as I can tell it's only because they want to "get away with" eating junk food, as if gaining a few pounds is the only problem eating McDonald's will cause them."

If you're young, male, and only overweight by 20-30 pounds, just about any diet plan will work for you.  Unfortunately, this is also the age group that gets most evangelistic about their own diet plan (which is usually the first one they've tried) once they lose that first 15-20.

And yes, aging sneaks up on you!  The problem most people don't realize is that looking old and feeling old are the product of decades of life choices...we can stop ourselves from aging as quickly, but we can't reverse much of the damage.  It's like most diseases: the best way to beat cancer is to not get it.  Etc.

JS