As she described things, you either run on glucose or on ketones. In my opinion, she left out an important alternative. She didn't broach running on FFAs.
A properly-functioning "young" body on a mixed diet (we'll leave alcohol out for now) gets a reasonable glucose peak after a meal, and burns the sugar off preferentially until the increase in insulin stores the excess and both glucose AND insulin drop. Then it burns fats. That's what the human body is designed to do.
Everyone observes that it takes a couple of days for ketones to start churning out in bulk, when starting a LC diet. What are you running on before this happens? First you burn through your stored glycogen, and the body has to perceive a glucose shortage ... then you get the magic -- physiological insulin-resistance and gluconeogenesis for those tissues which insist on using glucose. Hell, even THE BRAIN is now known not really to run exclusively on sugar -- the sugars seem to be converted to lactate. And the real magic: the brain is now recognized to turn FFAs to ketones, IN SITU. Essentially, part of the brain DOES run on fat, just not in the same way muscle cells do.
I believe that Amber is missing part of the equation. I believe the traditional fuel use went something like this in a healthy person:
- meal eaten of some mixture of protein, fat and carb;
- glucose preferentially burnt for a couple of hours;
- excess energy stored;
- until next meal (hours after -- no snacking for most of history), body seamlessly goes into lipolysis upon diminution of postprandial insulin;
- ONLY extended undernutrition leads to heavy ketone-body production. Otherwise, rinse-repeat.
It's only in the "damaged" body that you find difficulty in switching between fuels -- that's why restablishing metabolic flexibility is crucial in a person who has been overweight and is rectifying their dependence on glucose as the primary fuel.
That's also why fat-fasting is a tool for forcing a recalcitrant body into burning fat for fuel, and shouldn't be a lifestyle in and of itself -- it's too low in protein. That's why chasing high ketone-body concentrations is an academic sport and shouldn't be our GOAL for weight-loss or -maintenance. Ketone bodies in your blood imply undernutrition, which we consider "good" for weight-loss --
UNLESS you're "cheating" by taking ketone-salts or MCTs! Then it means "nothing." You can produce ketones on a very-high-carbohydrate (percent) diet, if you get the calories low enough. Weight-loss requires burning the fat off your butt for fuel -- not creating lots of ketones from your dietary fat.
When we use ketones for brain-health, that's a different story. Wooo's neurological issues are ameliorated by a diet which is protein-limited and high in the right kinds of fats -- burning too much glucose/lactate gives her a "short circuit." Galina prevents migraines with the diet she has refined. I find that running my brain on fat/ketone makes it function much better -- i sometimes wonder if i wouldn't be an Alzheimers risk, if i had continued to be a glucose-burner.
[aside: from a link someone put on twitter this week, I was inspired to wonder if we "20th-centurions" are predisposed to neurological sensitivity by low fetal DHA....]
Our hearts and other muscles seem to love to run on fats. They are "cheap and easy" fuels, which put no strain on the body to release and utilize ... so long as one has the metabolic flexibility to tap into them.
I mentally feel my best when I consume small amounts of mostly fat during the day, but I would feel deprived without one normal meal. I don't live alone, and it is a factor as well. Normally people choose the least restrictive regiment that allow them to function.
ReplyDeleteliving with someone else really does make it more difficult -- i'm grateful that my husband is so understanding! ...and he feels better on a lower-carb regimen, too.
DeleteTotally agree. Very nice summing up, including mentioning the consequences of low fetal DHA, the "cheap and easy" fuels (fats) that put no strain on the body to release and utilize (unlike all the fibrous stuff), and the metabolic flexibility that seems to be so impaired under modern conditions.
ReplyDeleteThanks!
thank YOU, Michael! :-)
Delete"That's why chasing high ketone-body concentrations is an academic sport and shouldn't be our GOAL for weight-loss or -maintenance."
ReplyDeleteSounds like sucking on ice cubes to lower your temperature.
:-) i realize people who are desperate to lose/maintain will do almost anything (Jimmy is the model here).... But this "chasing numbers" business is so dumb! Courting high ketone values is no different from worrying about total cholesterol.
DeleteJust today, the Paleo Diet blog has a post about fats. I agree with much of what the author is saying (e.g., adding lots of extra fat to your diet can impede weight loss, and don't go nuts with the nuts), her go-to fat are all plant based. What is it with so many young women being too prissy to eat animal fat? I'm not young anymore, but I'm one of the most straight-laced people I know, and I love animal fat. Maybe it's from being raised by anti-prissy parents who sometimes butchered their own elk and deer.
ReplyDeleteI think many people are so hypnotized by constant references to the Mediterranean diet as the holy grail of healthy eating, that they try to mediterioneanised their LCarbing. Atkins still is a diet devil in a mass opinion - lured innocent people with his promise of a weight loss into eating stakes and battered lobsters.
Deletewe've all been bombarded with the idea that coconut oil is a magic elixir for weight loss -- well, compared to corn oil it is, but i don't see it doing ANYTHING better than tallow, my personal favorite. if you have no gallbladder, it may be easier to digest and it's less greasy, topically, but that's about it, in my book.
Deletetallow has an additional benefit that i DON'T see in coconut or olive oil -- people who seem to have problems with constipation on a LC diet need to add more ruminant fats to their diets! when i was experimenting with more vegetables and got clogged up, it was the fat i drained off of my grass-fed ground beef (and clarified) that saved my ... ahem ... ass.
I googled coconut oil for a weight loss, and was overwhelmed with the amount of links with claims that coconut oil is a miracle weight-loss tool. You know, farmers couldn'fatten pigs with it, but corn worked every time. Big surprise.
DeleteI like it, it is my preferable cooking oil, I use it as a body moisturizer and a foot cream. My gallbladder is removed and I like the "lightness" of a coconut oil, but I have never ever noticed any fat-melting properties of it whatsoever.
I came to a conclusion that most enthusiastic blog-posts are here mostly for motivation purposes, but I am not saying that motivation is not important for the people, they already know what works for them, but adherence to their diet is often the weakest link.
It goes beyond weight-loss and Mediterranean diet claims--some of the same women who take pride in being as smart and competent as their male peers suddenly need a fainting couch at the thought of eating two strips of bacon or skipping their "veggies," as they always call them. If you want to ask them to have an elk burger or eat at McDonald's or a diner, get ready to hear, "Eeewww!" (But they'll hop into bed with random men. Poor risk assessment skills, I guess.)
DeleteThose plant fats are a lot more expensive than animal fats, too. ($10 a pound for coconut oil v. $2.99 for lard or $5 for organic butter.) And from an evolutionary standpoint, we probably ate a lot of animal than plant fat--and ate plant fat like nuts when the going was rough.
interesting -- I hadn't thought of that, Lori! most of my female friends are the rugged-individualist types these days. :-) no wonder you have a problem with people using "the abbreviated V-word" -- when a thing gets an associated with a "precious" or oversentimentalized concept, it tends to make me gag, too....
DeleteSome former vegetarians have said they easily dropped the idea of disliking meat. So in some cases, at least, all the eeewww is just an affectation.
ReplyDeleteParents don't do their kids (boys or girls) any favor by trying to remove all of their grit and making little princesses and goody-goodies out of them.
I guess rising a girl like a "little princes" may seriously complicate her future life. So many females are under a self-inflicted pressure to behave like they are out of that imperfect world creatures.
Deletein the names of all the gods -- WHERE'S THE "LIKE" BUTTON? this is such a passion of mine.... parents do their kids no favor in making them think they're the center of the universe!
DeleteOT -- does anyone remember the t-shirt which said "good little girls may go to heaven but bad little girls go everywhere"? [evil grin]
DeleteI remember the term "putting on airs"--from books, not hearing it in person.
Delete