I cannot tell you how many emails I get from people fretting over their ketone levels. It’s time to set the record straight on this issue. I wish there was someplace I could refer people for reliable information on this subject, but I haven’t come across a blog post or podcast interview that explains things satisfactorily. At least, not to my satisfaction. And that is and always has been my goal in writing my blog: I explain things the way I would want someone to explain them to me, if I were new to all this. And since no one—as far as I know, anyway—has tackled this subject the way I would, I finally had to just sit down and write this. If you feel it’s educational, please share it in the low carb and/or ketogenic circles you frequent, because I know this issue comes up all the time in ketogenic forums and Facebook groups. (And if you know of other good resources on this topic, feel free to provide a link in the comments, and I’ll update this post to include it.)
Okay, here goes.
There are few issues more controversial regarding ketogenic diets than whether you should measure your ketones. There are valid reasons to measure, but there are also a lot—a lot—of misconceptions about measuring ketones and how to interpret the data. So let’s get into when and why it’s a good idea to measure, who doesn’t need to measure, and most important, what the numbers mean. (I said who “doesn’t need to” measure rather than who shouldn’t measure because if you want to measure, then go ahead. There’s really no should or shouldn’t here. But if you choose to measure, you need to understand how to interpret and understand the numbers so you don’t jump to illogical and false conclusions.)
I will also be covering the difference between being fat adapted versus in ketosis. I tried to do it in a few posts awhile back, but I think I the way I explain it here is much better because I will show you the biochemical pathways involved so you will be able to see how it actually works. My hope is that this will go from a vague concept in your mind to, “Oh! NOW I get it!” And you will understand very clearly how you can absolutely, positively have a fat-based metabolism and lose body fat even if you’re not in ketosis.