Table 3.

Summary of the dietitian road map recommendations developed by the consensus group.

Topic	Recommendation(s) by the consensus group
Multidisciplinary team	The core treatment team should comprise a physician, dietitian/nutritionist and a nurse. If resources are available, also a psychologist/counsellor (highly recommended), social worker, home support worker and coordinator should be part of the multidisciplinary team
Nutritional status evaluation	- Blood Phe concentrations, anthropometrics and nutritional intake were identified as minimally required for follow-up
	- Blood Phe concentrations should be assessed monthly (or every 2 weeks in case of low blood Phe, <30 μmol/L), but may be monitored more frequently upon the metabolic team's discretion, e.g., when changing protein intake or pegvaliase dose
	- Nutritional intake is ideally monitored with each blood Phe measurement, preferably using a food frequency questionnaire in combination with 24-h recall or 3-day food records
	- Practical recommendations for additional nutritional assessments can be found in Table 2
Treatment goals of pegvaliase	- Pegvaliase should aim to maintain blood Phe levels below 240 μmol/L but more evidence on the safety of achieving physiological blood Phe levels will need to be collected before making any recommendation on the lower limit of the blood Phe target range
	- A normalised diet: at least 0.8 g of protein/kg/day (DRI for protein intake) from a mix of animal and plant sources, without any supplementation from protein substitutes, while ensuring that all nutrient requirements are met
	- Additional goals: improvements in neurocognition and (neuro)psychological outcomes, quality of life and emotional well-being
Adjustment of diet and protein intake	- When starting pegvaliase, the patient should be on a consistent diet, defined as: “The patient's protein intake, dietary pattern and lifestyle should remain approximately the same as before pegvaliase initiation”
	- An increase in natural protein intake can be considered when blood Phe concentrations are below 240 μmol/L but should be individualised
	- Natural protein should be increased by increments of 10–20 g per day
	- If the patient is taking protein substitutes, these should be reduced proportionally if this is possible, once natural protein intake is increased
	- Protein intake of vegan patients should be generally 20% more, but nutritional status needs to be calculated on an individual basis
	- In obese patients, care should be focussed on diet and exercise to reduce weight
Education	Patient education before and during treatment with pegvaliase is crucial, with a focus on nutritional intake and correct use of pegvaliase

DRI: dietary reference intake; Phe: phenylalanine.