Individuals may underestimate their calorie intake on a ketogenic diet, particularly due to the caloric density of fats, leading to an energy deficit that is smaller than intended.

“I always always underestimate it. Uh probably because just fat is so calorically dense, right? So the amount of egg yolks and a lot of fatty fish. This morning I had like three cans of sardines. Each can is 20 grams of fat and 15 grams of protein. And that's so 20 that's 60 grams of fat just from sardines and extravirgin olive oil, you know, and that's it adds up.”