To my knowledge, ketogenic nutrition support terminology either parenteral nutrition or enteral feedings concept is applied to patients with intractable seizure and some cases in inborn error of metabolism like carbohydrate disorder metabolism and characterized by high fat, low carbohydrate, and maintenance protein contents.
The goal of nutrition support in cancer patients is to minimize wasting but not for ideally nutrition repletion and gaining weight.
Also, The goal of nutrition support in patient with cancer (adult) maintenance support which is between 23- 25 KCla/kg/day. not anabolic support as theoretically high calories providing may feed cancer cells as stated in some studies.
I advise you to monitor other parameters like prealbumin or transferrin with CRP (if patient is not under any kind of stress) if you don’t see increasing in patient weight in order to if the patient got benefit from PN