But eating too much protein can reduce ketone production, thus making it more difficult to reach and maintain ketosis, which is why a true ketogenic diet has limits on protein intake as well as carbohydrate intake.
In short, relying less on carbohydrates for energy increases ketone production. Although the liver is always producing some ketones for energy from fat, the more the body shifts to fat as an energy source, the more its ketone production ramps up. But eating too much protein can reduce ketone production, thus making it more difficult to reach and maintain ketosis, which is why a true ketogenic diet has limits on protein intake as well as carbohydrate intake.