I'm A Keto Neuroscientist: This Is The Nutrient You May Be Lacking On Keto

His answer? Everyone's body reacts differently (and he's generally a whole foods type of guy), but there is one that deserves honorable mention: "The literature suggests that if you're on a ketogenic diet, many people [lack] carnitine," he says on the mindbodygreen podcast.

"Because your body is oxidizing and burning so much fat, it kind of burns through all its carnitine," D'Agostino says. He's not wrong: One study showed that while it's uncommon to have a true carnitine deficiency on keto, mild carnitine depletion may occur early on in the diet2—meaning, carnitine levels should go back to baseline after your body gets used to the keto diet (so don't fret), even though you may face some gaps in the beginning. 

Of course, you'll want to consult a professional before starting or changing any supplement routine to make sure you're getting the right dose for your body. It's also important to note, per the study above, that your carnitine levels will likely balance out after some time—so you might want to keep an eye on your levels and perhaps stop the supplements once you even out. We repeat: Consulting a doctor is your best bet for targeted, personalized results.

Mild carnitine depletion is common on keto, considering your body needs to transport more and more fatty acids into the mitochondria. It's typically not cause for alarm (the levels should stabilize; we suggest consulting your doctor if you have any concerns), but if you're feeling especially sluggish, perhaps think about adding the energy-supporting molecule into your routine—at least for a time.