Regarding the optimal macronutrient composition of the diet for individuals with PWS or PCSK1 deficiency, no consensus has yet been reached; some authors suggest a PWS diet consisting of approximately 25% protein, 50% carbohydrate, and 25% fat, whilst others have suggested the use of ketogenic diets or hypocaloric protein-sparing diets [33]. Here, PCSK1 is linked to hyperinsulinemic hypoglycemia, familial, 4.