Ketosis mimics the effects of prolonged fasting and starvation. For someone consuming 2,000 calories a day, they would only be allowed to consume grams of carbohydrates.
Most trials, across various health condition, have seen a keto diet modestly increase HDL-C levels. This can be due, in part, to an increase in overall fat intake. Some people may need to lower this to under 20 grams, and some can produce more ketones even above 50 grams.