Paul Halliday:

Exactly.  The Western interpretation of the "Mediterranean diet" is not exactly in congruence with the variety of actual Mediterranean diets that exist.

Max:

No, ketosis isn't the objective of this diet: you need to keep carbs very low to do that, as Jen mentioned above.  (Consuming the MCTs in coconut oil helps a lot, too.)  Being a more efficient fat-burner (which Mark Sisson talks about a lot) is a consequence of metabolic flexibility, which is not the same thing as ketosis: I discuss the difference in this article.

Summary: it's possible to eat like a predator and be in ketosis, but it's not necessary.  Eating carbohydrate in line with your body's needs, not snacking, and periodic exercise appear to be your primary tools for regaining your ability to oxidize fat for energy.

JS

Martin:

I know a lot of people claim that fish oil caps are necessarily rancid and therefore harmful -- but I've not yet seen any actual proof of that.  (Meanwhile, people are happily taking fermented cod liver oil...)  There's a reason they put vitamin E and/or other tocopherols in there, and package them in an opaque container, which is to prevent oxidation.  Just to be safe, I buy mine from major, high-volume mail-order retailers and store them in the refrigerator.

Meanwhile, it's always preferable to get EPA+DHA from real food, and I remain open to new evidence.  Yes, I've seen the study that says fish oil caps don't have a significant effect on heart disease vs. fish consumption.  However, as with any other uncontrolled, retrospective, self-reported dietary analysis, the number of potential confounding factors is so large that I'm reluctant to jump from there to "FISH OIL IS RANCID" (just to choose one example, people who actually eat fish probably have a much healthier diet in other ways), and the other benefits are large enough that I still recommend it for people who aren't getting it via food.

JS

Megan:

AFAIK even the purest of refined vegetable oils won't start a truck without first undergoing transesterification.  And as coconut oil is solid below 74 degrees F (and beef tallow is solid at 90+), they pose some obvious practical problems!  So olive oil is perhaps the only usable exception to my rule of thumb.

Your point is taken, though: technically one can use almost any oil as "fuel".

JS

Lara:

I tend to agree with Mark Sisson that lots of walking and other low-impact activity, plus occasional intense effort, is most healthy and sustainable over the long term.  The much-vaunted "persistence hunting" seems to involve average speeds of 4 MPH...a 15-minute mile, which is a brisk walk for most.

What seems to work for me is some sort of low-impact exercise every day, usually an easy bike ride comparable to a brisk walk or very slow jog, and taking 30-45 minutes.  Every few days I'll do something much more intense, like a heavy barbell workout in the gym (taking 60-75 minutes), and every so often I'll do something really big, like an all-day mountain bike ride or backcountry ski tour. (Or, under exceptional circumstances, climbing a mountain fasted.  Make sure to read the beginning of the article for some science on why every-day endurance exercise is counterproductive.)  Other examples would be game day in a competitive sport like soccer or basketball, a Crossfit metcon, an intense HIIT/Tabata workout, etc.  Note that genuine 100% efforts require at least three days for full recovery...

Jamie Scott frequently writes about exercise and training within different energy systems.

JS

Ben:

It's easy to fall into the long-disproved Cartesian trap of mind/body duality -- but this is the 21st century, and we need to understand that sound nutrition improves our mental functioning as well as our physical functioning. 

JS