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Table 2 Summary of Consensus Statements

From: Development of national consensus statements on food labelling interpretation and protein allocation in a low phenylalanine diet for PKU

PHASE 1

Consensus statements

Delphi Process – Round 1 %  agreement (n)

Delphi process – Round 2 %  agreement (n)

Delphi process – Round 3 %  agreement (n)

Paediatric Dietitians

n = 29

18 centres

Dietitians in adult practice

n = 17

11 centres

Paediatric Dietitians

n = 36

18 centres

Dietitians in adult practice

n = 19

12 centres

Paediatric Dietitians

n = 25

10 centres

Dietitians in adult practice

n = 20

13 centres

In PKU, low protein, free, unmeasured or non-exchange foods are referred to as ‘exchange-free’ foods.

93 (27)

100 (17)

Agreed

 

Agreed

Agreed

Foods are ‘exchange-free’ if protein content is ≤ 0.5 g/100 g of food:

 • e.g. sweets

90 (26)

88 (15)

Agreed

 

Agreed

Agreed

 • e.g. gravy

97 (28)

76 (13)

Agreed

 

Agreed

Agreed

Exceptions that remain ‘exchange-free’ if > 0.5 g per 100 g or per 100 ml of food:

 • all herbs, spices and seasonings (irrespective of the protein content on the food ingredient label, due to the small quantities consumed);

100 (29)

100 (29)

Agreed

 

Agreed

Agreed

 • fats (oils, butter, margarine) (as only small amounts are used)

100 (29)

88 (15)

Agreed

 

Agreed

Agreed

 • ‘wet cooking sauce’ if the protein content is ≤1.0 g/100 g

100 (29)

65 (11)

Agreed

 

Agreed

Agreed

Soya sauce:

ROUND 1: soya sauce that contains Phe ≤ 1.0 g/100 ml (based on the quantities commonly consumed)

97 (28)

88 (15)

N/A

 

N/A

N/A

ROUND 2:

 • Option 1: Any soya sauce that contains protein ≤1.0 g/100 ml is considered ‘exchange-free’

N/A

N/A

25 (9)*

 

N/A

N/A

 • Option 2: Any soya sauce that contains protein ≤1.5 g/100 ml is considered ‘exchange-free’

N/A

N/A

67 (24)*

 

Agreed

Agreed

 • Option 3: 2 tablespoons per day of any soya sauce is ‘exchange-free’ (existing guideline)

N/A

N/A

14 (5)*

 

N/A

N/A

For ‘wet cooking sauces’ with a protein content > 1.0 g /100 g:

  • If they contain exchange ingredients (e.g. cream, egg, coconut) they are counted as an ‘exchange’ food;

100 (29)

65 (11)

Agreed

 

Agreed

Agreed

  • If they contain ‘exchange free’ ingredients only (e.g. fruit/vegetables) they are considered an ‘exchange-free’ food.

100 (29)

65 (11)

Agreed

 

Agreed

Agreed

Allocation of fruits and vegetables (except fresh/frozen potatoes)

ROUND 1:

 • Fruits & vegetables (except potatoes) containing a Phe content ≤75 mg/100 g weight will be consisdered ‘exchange-free’ foods.

100 (29)

100 (17)

Agreed

 

Agreed

Agreed

 • Fruits & vegetables with a Phe content of ≥100 mg/100 g, use the actual Phe content to calculate exchange amounts.

100 (29)

100 (17)

Agreed

 

Agreed

Agreed

 • Phe content 76-99 mg/100 g weight of fruit & vegetable: allow 1 portion/day ‘exchange-free’

86 (25)

82 (14)

N/A

 

N/A

N/A

ROUND 2/3:

 • Option 1: Fruit & vegetables containing a Phe content 76–99 mg/100 g weight of fruit & vegetable, count as ‘exchange’ foods

N/A

N/A

35 (13)*

 

64 (16)

Agreed

 • Option 2: Allow 1 exchange portion ‘exchange-free’ per day with additional portions to be counted as an exchange

N/A

N/A

42 (15)*

 

24 (6)

 

 • Option 3: Only 1 portion of these fruits/ vegetables are allowed ‘exchange-free’ per day (existing guideline)

N/A

N/A

33 (12)*

   

Additional statement: Fruits & vegetables containing a Phe content of 76–99 mg/100 g, use a standard ‘exchange’ amount of 60 g weight to provide approximately 50 mg/Phe

N/A

N/A

97 (35)

 

Agreed

Agreed

 • Fresh/frozen potatoes are counted as ‘exchange’ foods. If the Phe analysis is available, this will be used to determine exchange amount; if Phe analysis is unavailable (e.g. potato waffles, hash browns), the protein content will be used to calculate exchange amounts.

97 (28)

94 (16)

Agreed

 

Agreed

Agreed

 • Manufactured fruit/vegetable products containing only fruits or vegetables that are designated as ‘exchange-free’ in their fresh form, should still be considered ‘exchange-free’ foods. However, if they contain added ingredients that are protein containing (e.g. milk or wheat), they are counted as ‘exchange’ foods with their protein content used to determine the amount of food allocated for one Phe exchange.

100 (29)

88 (15)

Agreed

 

Agreed

Agreed

 • Vegetable crisps containing exchange free vegetables are counted as ‘exchange’ foods due to the concentration of protein associated with cooking methods; their protein content should be used to determine the exchange amount.

88 (21)

88 (15)

Agreed

 

Agreed

Agreed

Low protein special foods:

 • Low protein special products (e.g. bread, flour) should be allowed without measurement if all ingredients are ‘exchange-free’, irrespective of the phenylalanine analysis per 100 g on the label.

93 (27)

76 (13)

Agreed

 

Agreed

Agreed

alculating food protein exchanges from protein analysis on the food label:

 • Food ‘exchange’ amounts for food portions should be rounded up or down based on the ‘rule of maths’ (Table 3 for guidance).

97 (28)

94 (16)

Agreed

 

Agreed

Agreed

 • Patients/caregivers are advised to read ingredient lists as well as the protein content on food labels. The following was concluded as guidance:

100 (29)

88 (15)

Agreed

 

Agreed

Agreed

  - If ingredients contain protein but the protein label content appears low, establish a more accurate protein analysis before consuming.

100 (29)

88 (15)

Agreed

 

Agreed

Agreed

  - If ingredients are ‘clearly’ exchange-free but the protein label content is not available then it is suitable to give as an exchange-free food.

100 (29)

100 (17)

Agreed

 

Agreed

Agreed

  - If there is no protein content on the product label, but it contains exchange ingredients, an accurate protein analysis should be obtained before consuming.

100 (29)

100 (29)

Agreed

 

Agreed

Agreed

  - If a label states its protein content is 0 g but ≥1 ingredient contains a protein source (e.g. gelatine), avoid until an accurate protein analysis is known.

97 (28)

65 (11)

Agreed

 

Agreed

Agreed

Agree with all consensus statements (as above)

N/A

N/A

N/A

N/A

N/A

75 (15)

Separate maternal PKU statements preferred

N/A

N/A

N/A

N/A

N/A

40 (8)

PHASE 2

Consensus statements

Delphi Process – Round 1 % agreement (n)

Delphi process – Round 2 % agreement (n)

Final Decision

Paediatric Dietitians

n = 19

13 centres

Dietitians in adult practice

n = 9

8 centres

Paediatric Dietitians

n = 19

11 centres

Dietitians in adult practice

n = 14

8 centres

 

Low protein milk

ROUND 1:

 • Option 1: A daily volume of 250 ml is exchange free if it provides ≤0.5 g protein (25 mg Phe)/daily

16 (3)

56 (5)

N/A

N/A

 

 • Option 2: A daily volume of 500 ml/daily volume is exchange free if it provides ≤0.5 g protein (25 mg Phe) /daily

42 (8)

11 (1)

N/A

N/A

 

 • Option 3: A daily volume of 1000 ml/daily volume is exchange free if it provides ≤0.5 g protein (25 mg Phe) /daily

21 (4)

22 (2)

N/A

N/A

 

 • Option 4: A daily volume of 1000 ml/daily volume is exchange free if it provides ≤0.5 g protein (25 mg Phe) /daily

11 (2)

11 (1)

N/A

N/A

 

 • Unsure

11 (2)

–

N/A

N/A

 

ROUND 2:

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

N/A

N/A

84 (16)

79 (11)

Agreed

 • Any low protein special milk (e.g. Sno Pro, Taranis, Prozero) that provides a total phenylalanine intake of > 25 mg (half an exchange) over 24 h when consumed should be counted as an exchange food. If the total phenylalanine intake provides ≤25 mg over 24 h, it should be considered exchange-free.

N/A

N/A

79 (15)

71 (10)

Agreed

Soups that contain exchange-free ingredients are exchange-free.

79 (15)

78 (7)

N/A

N/A

Agreed

Any coconut yoghurt/dessert with a protein content ≤0.5 g/100 g is exchange-free.

79 (15)

56 (5)

N/A

N/A

Agreed

Any dried coconut product with a protein content > 0.5 g/100 g should be counted as an exchange food.

95 (18)

89 (8)

N/A

N/A

Agreed

Any food containing ≤0.5 g/100 g protein (but contains gelatine) can be allocated as exchange-free as it is likely to contain ≤10 mg phenylalanine from this source.

95 (18)

89 (8)

N/A

N/A

Agreed

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

100 (19)

100 (9)

N/A

N/A

Agreed

PHASE 3

Consensus statements

Delphi Process – Round 1 % agreement (n)

  

Final Decision

n = 17

13 centres

   

Low protein special foods

If the special low protein food contains exchange ingredients but contains up to 25 mg Phe/100 g, it is exchange-free. If the special low protein food contains exchange ingredients but contains ≥26 mg Phe/100 g, it is an exchange food.

94 (16)

  

Agreed

  1. NB: Dietitians covering both paediatrics & adults – responses are included in both groups. *some dietitians were undecided and chose 2 options