I thought Keto was low carb, not low calorie
This is a combination of both.
It’s low carb, but also moderate protein.
I could be wrong, but I think in some ways Keto mimics low calorie diets.
A very low-calorie ketogenic diet (VLCKD) is characterized by low daily caloric intake (less than 800 kcal/day), low carbohydrate intake (<50 g/day) and normoproteic (1–1.5 g of protein/kg of ideal body weight) contents.
Keto is normally very low carb, but this diet was very low carb, moderate amount of protein and increase of very healthy fats. Other Keto diets are very low carb, high protein and high good fats.