Is Fat the Preferred Fuel Source in the Body – Q&A
So let’s turn to human physiology and talk about what fuel the body ‘prefers’ to use, with the above definition in mind. Now, for the most part, most tissues in the body can generate energy (ATP for the biochemically literal minded) from either glucose or fatty acids. There are exceptions, mind you; the brain uses almost exclusively glucose but shifts to ketones under certain conditions. What it can’t use is fatty acids directly. There are couple of other weird ones, a handful of tissues in the body that only use glucose: the retina is one, part of the kidney, there’s a third I’m forgetting. There’s one other exception to this that I’ll come back to at the end.
