Table 5.

Summary of Final Consensus Statements for PKU

1. Any food given without measurement is referred to as an exchange-free food.

2. Foods are ‘exchange-free’ if they contain protein ≤0.5 g/100 g. e.g. sweets, coconut products, foods containing gelatine. Exceptions:  • herbs, spices, seasonings, fats (oil, butter, margarine) – as the quantity used is very small.  • Any soya sauce containing protein ≤1.5 g/100 ml is exchange-free.  • Any ‘wet cooking sauce’ containing protein ≤1.0 g/100 g is exchange-free. If it contains > 1 g protein/100 g and contains exchange ingredients (e.g. cream, egg, coconut) it should be counted as an exchange food. If it contains > 1 g protein/100 g and contains ‘exchange free’ ingredients only (e.g. vegetables such as tomatoes) it is an exchange-free food.

3. ‘European PKU guideline 2017’ [3] is used for fruit and vegetable allocation:  • Phe content ≤75 mg/100 g weight of fruit and vegetables: exchange-free.  • Phe content ≥76 mg/100 g weight of fruit and vegetables: count as exchange foods. Exception: Potatoes – use Phe analysis to determine exchange amounts. If potato products contain additional exchange ingredients (e.g. wheat flour, or milk), use protein analysis on the packet to determine its exchange amount.

4. A standard exchange amount of 60 g for any fruit/vegetables containing Phe between 76 and 99 mg/100 g will be used. For any fruit/vegetables containing Phe ≥100 mg/100 g (e.g. peas, sweetcorn), the actual Phe content will be used to calculate exchange amounts.

5. If any frozen/canned product is designated ‘exchange-free’ in their fresh form, they are considered exchange-free foods e.g. carrots, mushrooms, tomatoes. Exception: Vegetable crisps - although derived from exchange-free food, are concentrated in protein due to cooking methods so should be counted as exchange foods. Use protein content per 100 g to determine the amount that can be given for one exchange.

6. Low protein special products (e.g. bread, flour) are exchange-free if all ingredients are exchange-free. If they contain exchange ingredients but contains ≤25 mg Phe/100 g, they are exchange-free. If they contain exchange ingredients but contains ≥26 mg Phe/100 g, they are an exchange food.

7. Any low protein special milk that provides a total Phe intake of > 25 mg (1/2 exchange) over 24 h in the volumes consumed, should be counted as an exchange food. If the total Phe intake provides ≤25 mg over 24 h, it should be considered exchange-free.

8. Any plant milk (e.g. coconut, rice, almond) that provides a total protein intake of > 0.5 g over 24 h in the volumes consumed, should be counted as an exchange food. If the total protein intake provides ≤0.5 g/100 g over 24 h, it should be considered exchange-free.

9. Soups that contain exchange-free ingredients are exchange-free. If soups contain exchange ingredients and their protein content is > 0.5 g/100 g, then they should be counted as an exchange food.

10. Weight rather than the volume of ice-cream should be used to calculate the protein exchange amount.

11. Food ‘exchange’ amounts for food portions should be rounded up or down based on the ‘rule of maths’. See Table 3

12. All patients/caregivers are advised to read ingredient lists as well the protein content/100 g on food labels. If ingredients are protein containing (but the protein analysis appears very low), it is important to establish more accurate protein analysis before consuming. If ingredients are ‘clearly’ exchange-free, then it is appropriate to give as an exchange-free food even if the protein analysis is unavailable on the label. If there is no nutritional analysis on the product but it contains ingredients that are exchange foods, then further food protein analysis must be obtained before consuming. If a label states protein content is 0 g but one or more ingredients is a protein source (e.g. gelatine), then an accurate food protein analysis must be obtained before consuming.