Protein diet - minimal (metabolic)

Aim

To provide a minimal protein intake while maintaining adequate intake of energy, for patients who are unable to metabolise normal or low protein intake.

Characteristics

Extremely low protein. Diet includes no animal protein, no dairy, no soy/legumes or nuts. Special commercial low protein products (bread, pasta, biscuits, cereal) must be used in place of regular breads and cereals. All fruits are allowed and a limited range of vegetables. To maintain adequate energy intake, high energy supplements are used such as sugars, glucose polymers and fats.

Nutritional supplements of amino acids and/or vitamins and minerals are required for nutrient adequacy but need to be prescribed depending on the metabolic disorder and dietary intake.

Each individual patients' meal plan needs to be planned by a dietitian in consideration of the specific metabolic disorder and patients’ requirements. The requirements may change during the admission depending on clinical need and biochemical monitoring.

Indications

Patients with inborn errors of protein metabolism suffering from metabolic decompensation or elevated biochemistry, such as Phenylketonuria (PKU), Maple Syrup Urine Disease (MSUD), urea cycle disorders, organic acidaemias.

Metabolic disorders are rare but increasingly diagnosed and managed throughout the lifecycle. Treatment protocols are different for different conditions. An individual’s treatment protocol will also change with age and with biochemical monitoring.

Nutritional adequacy

Nutritionally inadequate – must be used in conjunction with a prescribed dietary supplement. Energy needs must be met for adequate metabolic control. This diet, without supplementation, will be inadequate in many nutrients including vitamin B12, iron and calcium. The diet must be planned for each individual patient by a dietitian and regular follow-up provided.

Precautions

Must only be used when ordered by a physician and under supervision of a dietitian. Short term use only. Prolonged use may precipitate metabolic crisis. Nutritionally inadequate.

Must be used in conjunction with prescribed dietary supplement(s) to provide appropriate amounts of amino acids and/or energy. Specific daily amounts of supplements will be required and intake must be monitored.

This diet may be used as a base for the addition of restricted amounts of protein containing food, as soon as clinically possible during an admission, on the basis of biochemical monitoring. Some metabolic conditions have specific treatment to be followed during illness, which may differ from the diet the patient usually follows. Medical status of patient must be assessed before deciding on the degree of dietary restriction.

Tolerance of protein will depend on patients’ age, gender, weight, height, growth rate and medical condition, and may change during the course of a hospital admission depending on clinical state and biochemical monitoring.

Assessment and follow up by a dietitian is essential. Growth, weight, and nutrient intake must be monitored as these can be compromised on such a restrictive diet. Regular biochemical monitoring is essential to prevent metabolic crisis and nutritional inadequacy.

Specific menu planning guidelines

	Allowed	Not allowed
Hot main dishes	<2g protein per serve Vegetable casseroles with allowed vegetables/combined with low protein rice/low protein pasta If <1000kJ/serve, add 10mL oil/10g margarine/20mL cream/20mL sour cream Added oil, margarine, cream/sour cream (portion controlled servings)	Any containing meat, chicken, fish, egg, milk, cheese, yoghurt, soy, nuts, legumes, soy, vegetarian products (e.g. TVP)
Sauces, gravies	<1g protein/serve Cream in limited amounts, sweet and sour sauce, tomato based sauces Tomato sauce in portion controlled servings Commercial mayonnaise	Meat/chicken/fish based gravy or stock, milk or cheese sauce, yoghurt, Vegemite™, soy sauce
Starchy vegetables/pasta/rice	<1g protein/serve Low protein pasta/low protein rice Low protein rice/low protein pasta dishes with <1g protein/serve If <500kJ/serve, add 10mL oil/1 portion controlled/15mL salad dressing	Potato, couscous Any dishes prepared with the addition of meat, milk or cheese
Vegetables	<1g protein/serve All others, including carrot, tomato, capsicum, onion, zucchini, eggplant, cabbage, beetroot, lettuce, cucumber Serve with 2 x portion controlled butter/ margarine	Cauliflower, broccoli, pumpkin, potato, sweet potato, peas, corn, mushrooms, spinach, avocado, green beans, legumes Any prepared with the addition of meat, milk or cheese
Soups	<1g protein per serve Tomato or vegetable soup containing vegetable stock or cream/sour cream Serve with 20mL cream/20mL sour cream/ 20mL Glucose polymer syrup (see recipe below)	Any containing meat, chicken, fish, egg, milk, cheese, yoghurt, soy, nuts, legumes, potato, peas, corn, or other not allowed vegetables, soy sauce Meat/chicken/fish stock
Sandwiches	<1g protein/serve (2 slices bread + filling) Low protein bread only with margarine/butter and low protein fillings (e.g. cucumber, tomato, salad vegetables, commercial mayonnaise, jam, honey) Use 2 x serve spread	All others
Salads, dressings	<1g protein/serve (can include appropriate Band 3 salad) Salad vegetables (e.g. carrot, cucumber, capsicum, tomato, eggplant, lettuce, etc) Serve with high fat dressings such as French dressing of oil and vinegar/lemon Mayonnaise	Any containing meat, chicken, fish, egg, milk, cheese, yoghurt, soy, nuts, legumes, potato, peas, corn, other not allowed vegetables, soy sauce
Breads, cereals	<0.3 g protein/serve Low protein bread and low protein breakfast cereals only Serve with low protein milk substitute	All others including standard breads, cereals, breakfast cereals
Spreads	Margarine, butter, jam, honey 2 serves per meal	Peanut butter, Vegemite™, fish pastes, hazelnut spread
Hot breakfast choices	Fried/grilled plain or herbed tomato	All others, including eggs, bacon, sausages, hash browns, mushrooms
Fruit	Other fruit – fresh, canned in syrup, or cooked Serve with 20mL glucose polymer syrup/ 20mL cream in portion controlled servings to fortify energy	Banana, passionfruit, dried fruit
Yoghurt	None	All
Desserts	<1 g protein/serve Jelly produced with vegetable gum and glucose polymer Low protein creamy rice made on low protein rice and milk substitute Low protein custard made on milk substitute and low protein custard powder Cream in limited amounts If <700kJ/serve, serve with 20mL cream or 20mL glucose polymer	All others including dairy desserts, jelly containing gelatine
Milk and cheese	<0.4g protein and >400kJ/100mL milk Rice beverage not containing chickpeas with added glucose polymer or fat Commercial low protein milk alternatives and prescribed nutritional supplements Coffee whitener (see recipe below) Cream beverage (see recipe below)	Milk Cheese
Beverages	Fruit juice, soft drinks/cordials containing sugar Energy content of drinks to be fortified to 4.2kJ/mL with protein free energy supplement (e.g. glucose polymer or fat)	Drinks containing aspartame (additive numbers 951 and 962) or other artificial sweeteners Any beverages containing milk or soy protein
Biscuits	<0.2g protein/serve Low protein crackers and biscuits only Serve crackers with butter/margarine	All others, such as standard commercial sweet and savoury biscuits and crackers
Miscellaneous	Sugar, cream (portion controlled servings)	Artificial sweeteners

Coffee whitener recipe: 10g coffee whitener + 10g glucose polymer made up to 100mL water
Cream beverage recipe: 20mL cream + 10g glucose polymer made up to 100mL with water
9kJ/mL Glucose polymer syrup recipe: 56g glucose polymer added to 60mL water (makes 100mL)

References

1. Agency for Clinical Innovation. Nutrition standards for paediatric inpatients in NSW hospitals. Sydney 2011.
2. Agency for Clinical Innovation. Nutrition standards for adult inpatients in NSW hospitals. Sydney 2011.
3. Dietitians Association of Australia. 2009. Nutrition Manual 8th ed. Canberra: DAA.
4. American Dietetic Association. Paediatric Nutrition Care Manual. Chicago: ADA.
5. Food Standards Australia New Zealand. 2010. NUTTAB 2006 Online version. Foods that contain protein.
6. American Dietetic Association 2009. Paediatric Nutrition Care Manual. Chicago: ADA. (accessed 26 April 2010).
7. Shaw V and Lawson M. 2007. Clinical Paediatric Dietetics. 3rd Edition. Blackwell Publishing.
8. Acosta PB. 2010 Nutrition Management of Patients with Inherited Metabolic Disorders Jones and Bartlett Publishers.