The organs tend to specialize in (using different) energy sources. The brain likes glucose, but can live on ketones and lactate too. The heart likes fat and lactate. The muscles can use anything and, in a splendid evolutionary kind of elegance, the muscle makes lactate, which it can re-use as fuel and becomes a fuel to offset the glucose requirements of the brain. The ketones produced when the muscles metabolize fat also become an energy source for the brain. It is so elegant and efficient. Butter still has all those bovine IGF and insulin loads that are best avoided. Dairy is inflammatory too.

Most of the time I am probably in what is called ketosis, because I burn fat and ketones are their metabolic derivative. But, back when I used to test now and then because of my wife's and son's diabetes I never showed spilled ketones in my urine. As noted above, ketones circulate as an energy source; I probably burn mine.

There is plenty of fat deep inside the meats we eat and the outer layer of fat is almost always oxidized because of its exposure to the air. Oxidized fats promote a large burst of free radicals.

I don't know how people ever thought I recommended castor oil. The table that lists it (in my book) is an error that I could not get my publisher to fix. I used to use castor oil in my racing motorcycles; leave it for that. The table should have said cod liver oil. Ah well. If one reads the text you will see that I note that the castor bean contains one of the most deadly toxins known, ricin; the old Soviet spy's favorite poison. Canola oil is rapeseed oil, grown in Canada, and it was given that name as marketing ploy. I say there is no need to consume any man-made, bottled, refined oils, especially if they are from corn, the major source these days. I just don't cook in oil at all, except to lightly sauté asparagus or salmon.

FED:

In my experience, I have often seen that individuals who are just starting on diets similar to The New Evolution Diet begin consuming large quantities of fruit and nuts/seeds. We’ve been told for years that these foods are unquestionably “healthy” and the idea that consumption of them should be moderated is almost verboten. Do you have any words of wisdom for someone just starting on The New Evolution Diet regarding fruit and nuts?

Art: Many fruits are very sugary and are bred for their sugar content. Ever notice how cakes are colored with frosting that are found in fruits? We go for colors when we eat for very good reasons. But, while fruit may have been difficult to acquire and seasonal during our earlier life as foragers, they are available year round and in abundance now. Most fruits do not even register on the GI scale because it takes 50g of carbohydrate to measure GI. But, a large plate of fruit would have a sizable glycemic load. We love fat and glucose because they were so scarce and signaled high energy content. OK, just realize that your primitive brain is still guiding your choices. It will give you a bit more tolerance for your cravings when you see a large bowl of fruit.

FED: In your book, you describe your average session at the gym as a combination of high intensity intervals on a recumbent bike, machine-based exercises (leg extension, leg curl, leg press) and free weights (barbell row, incline dumbbell chest press). You also take part in and recommend “functional” workouts (exercises patterned after real-world situations) like throwing a medicine ball, sprinting, playing tug-of-war, running stairs and doing squat jumps. If a person were to focus on one or the other (machine-based or functional exercises), which would you recommend and why?

Art:

Machines are a pretty safe way to work out. They do not challenge proprioception very well, but they build a (fitness) base for doing that in a work out aimed at balance and poise. I like a bit more wildness and action, but I always come back to weights, free or machine-based.

The number one problem for most people is a lack of muscle and strength, they are predictive of the risk of death, probably more so than cholesterol and all the other metabolic readings that are done.