Ketogenic diets, when followed ad libitum, can lead to a spontaneous reduction in daily caloric intake by 400 to 900 calories compared to habitual intake.

“So, 'ad libitum' means that you are not consciously calculating or restricting, you are just eating - What you want? - as desired. - Mm-Hmm. - And so, when you assign somebody a ketogenic diet where you say, "Hey, avoid this, and that carb food, avoid carbs, and you can eat as much as you feel like with the proteins and the fats. Go do it." What happens when you assign somebody that, is they spontaneously eat across the range of studies, somewhere between 400 and all the way to 900 calories less per day c ompared to their habitual intakes, or compared to the control diet intakes.”