Carmen Yeung
TMH Dietitian (APD) yeungkmc@ha.org.hk


Aim to limit the dietary leucine intake and minimise formation of isovaleric acid.

Sufficient leucine must be given for normal growth requirements


Usually a modest protein restriction 2g/kg in infant, then decrease to 1.0 -1.5g/kg in young children, and combined with adequate energy intake is sufficient to limit the production of isovaleric acid.
( Am J Med Genet C Semin Med Genet, 2006, 142C 95-103)

Some reports on treatment with leucine free amino acids and protein intake restricted to below “safe levels”.
Clinical Paediatric Dietetics, 3 rd edition


Usually a modest protein restriction 2g/kg in infant, then decrease to 1.0 -1.5g/kg in young children, and combined with adequate energy intake is sufficient to limit the production of isovaleric acid.

Some reports on treatment with leucine free amino acids and protein intake restricted to below “safe levels”.

IMPORTANT: Ensure adequate intake of all vitamins and minerals


May be very sick and in intensive care

A protein free feed is given while the infant is stablised, protein is then gradually introduced.
(Clinical Paediatric Dietetics, 3 rd edition)

Our case, start with protein free formula (PFD-1), and then support with protein contains formula (Similac), the leucine was given according the Nutrition Support
Protocols from Ross Metabolic Formula System

Recommended intake of leucine


On discharge, our patient is weight at 3.09kg

Diet order:
Similac ≤ 80ml x 4 feeds/d
IVA Anamix ≥80ml x 4 feeds/d
Total: 410kcal (= 135kcal/kg/d)
10g protein (=3.23g/kg/d)
444mg leucine (= 148mg/kg/d)

Regular Diet FU is essential to monitor the total calories, protein and leucine intake for normal growth


Aim: reduce production of potentially toxic metabolites from protein catabolism, and provide adequate energy intake (reduced appetite occurs naturally)

Estimated energy requirement (EAR) could up to 30% more than usual requirement during acute illness.

Adequate hydration

Requires frequent feeding, usually Q2-3H


Adequate protein intake for growth and development, but not excessive.
 keep safe level intake of leucine

Requirement of ~800mg/d in infancy, gradually up to
~1000-1500mg for normal growth

Where is the leucine from?

(Each of the following food contains 50mg leucine)
Food
Meat/ Poultry
Fish (cooked)
Chicken (cooked)
Beef (cooked)
Egg yolk (cooked)
Milk/ Dairy
Cow’s milk
Yoghurt
Ice-cream
Milk chocolate
Cereals
Baby Rice cereal (raw)
Rice (cooked)
Bread
Pasta (cooked)
Potato (boiled)
7g
25g
10g
15g
60g
Weight
2.5g
2.5g
2g
3.6g
15ml
10g
15g
5g
1 oz = 30g
1 egg yolk = 13g
~ 2 teaspoon
1 small cube
~ 1 tablespoon
~ 1 tablespoon
1/3 slide bread
1 egg size
Weighing scale, measuring spoons and cups are required for food preparation

Meal sample
18 months old girl, BW 12kg
Food Calories Protein
Breakfast IVA Anamix 240ml 165kcal 4.8g
Leucine
0
Lunch Noodle ¾ bowl 200kcal 4g
Cooked meat ½ oz 40kcal 3.5g
Vegetable ¼ bowl 20kcal 0g
4Ex leucine (200mg)
5Ex leucine (250mg)
0
Afternoon tea
Dinner
IVA Anamix 240ml 165kcal 4.8g
Supper
TOTAL:
0
Rice ¾ bowl 200kcal 4g
Cooked meat ½ oz 40kcal 3.5g
4Ex leucine (200mg)
5Ex leucine (250mg)
Vegetable ¼ bowl 20kcal 0g 0
IVA Anamix 240ml 165kcal 4.8g 0
1015kcal 25.4g protein 18Ex Leucine (900mg)


The amount of Leucine can be estimated from the protein content of the food, for example

Per 100g baby cereal
Energy
Protein
Carbohydrate
Fat
378kcal
7.4g
85g
0.9g
Calculate: 50/ protein in 100g
= 50 / 7.4
= 7g baby cereal contains 50mg leucine (= 1 exchange of leucine food)


Not to over restricted protein intake

Monitor leucine intake

Reinforced good diet compliance

Comply with weighting food items

Food label reading

Basic calculation of diet