AIMS OF NUTRITIONAL MANAGEMENT OF CHILDHOOD AND ADOLESCENT TYPE 1 DIABETES
. Provide appropriate energy and nutrients for optimal growth, development and health . Achieve and maintain ideal body weight . Achieve and maintain optimal glycaemic control on an individual basis, balancing food intake with metabolic requirements, physical activity and insulin treatment . Prevent hypo- and/or hyperglycaemia due to insulin, illness and exercise . Reduce the risk of long-term micro- and macrovascular complications . Preserve social and psychological well-being
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‘PROVIDE APPROPRIATE ENERGY AND NUTRIENTS FOR OPTIMAL GROWTH, DEVELOPMENT AND HEALTH’
Energy and Nutrients Children with well-controlled diabetes have similar average energy intakes and nutrient requirements as their peers. As individual daily intakes and requirements vary due to growth, maturity and exercise, nutritional require- ments need to be reviewed regularly with the use of height/weight growth charts. All advice should aim to achieve ideal body weight while meeting the recommendations specified in the Dietary Reference Values (DRVs) for the United Kingdom (18).
Growth in Relation to Energy Balance and Metabolic Control Children’s growth rate is continually changing but the phases of particularly rapid growth are in infancy and puberty.
Health care professionals need to be made aware that for optimal growth between 6 and 12 years children with diabetes must double their energy intake.
Total energy and protein intake needs to increase at this time.
However after these rapid phases of growth, or cessation of growth, failure to reduce energy intake will lead to obesity.
Adjusting dietary intake during these continually changing metabolic demands is central to the dietary management of childhood diabetes and requires ongoing regular review by a trained paediatric dietitian.
Growth potential may not be fulfilled when glycaemic control is poor, as glycosuria can cause significant urinary energy loss while insufficient insulin treatment can cause inadequate anabolism.
Energy requirements, carbohydrate intake and insulin doses increase throughout childhood and rise markedly during puberty.
Adolescents and parents need to be reassured that increasing carbohydrate intake is both normal and essential at this time and will not jeopardise overall metabolic control.
Parents often compensate for the increased appetite of puberty by increasing inappropriate non-carbohydrate foods that are high in fat and/or protein.
In boys, particularly, appetite can increase dramatically during the pubertal growth spurt and parents and adolescents need to appreciate that any increase in food intake should be accompanied by an increase in insulin dose.
Protein The normal protein requirements are: . 2 g/kg per day in early infancy . 1 g/kg per day for a 10-year-old . 0.8 g/kg in later adolescence towards adulthood
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Children in Western countries however find it easy to exceed these requirements, obtaining 15, 20% of their total energy intake as protein (19), while a safer level is nearer 10, 15% (1,19,20).
Proteinuria (albumin excretion rate >300 mg/min) is uncommon before puberty but microalbuminuria may start or accelerate during puberty.
Sustained high protein loads may be detrimental to renal function, especially if there is renal disease (19,21), and this is particularly important in adolescents.
However, any protein restriction should not be allowed to compromise normal growth and maturation and it is essential under these circumstances that careful nutritional and metabolic assessment is carried out.
Animal sources of protein are associated with higher fat intakes, especially saturated fat and therefore should not be consumed in large amounts.
Vegetable protein is lower in fat, higher in fibre and complex carbohydrates and should therefore be encouraged.
Until further evidence is available it is not necessary to decrease protein intake below that recommended for non-diabetic children and in the UK the national standard DRVs for Food Energy and Nutrients for the United Kingdom should be adhered to (18).
Carbohydrate Children in the UK achieve 51% of total energy intake from carbohydrate (22); however, children with diabetes find it more difficult to achieve the recommended targets and have a lower reported carbohydrate intake of 49% (23). More practical suggestions may be useful to encourage larger amounts of carbohydrate to prevent excess protein and fat intakes.
Sucrose Work in adults with diabetes has shown that sucrose has a lower glycaemic index than most starches (24,25).
Studies in children have shown no correlation between glycaemic control and ‘total’ sucrose intake; however, if sucrose is eaten in isolation and excess this will affect control (26,27).
These findings support a more liberal approach to sucrose intake when part of mixed meals or mixed with foods with a low glycaemic index, and this more flexible approach to sucrose can make food more palatable to children.
It is reasonable to follow the recommendations for sucrose for the general population, that for many countries is less than 10% of total energy.
In addition to glucose, sucrose can be used before exercise and for the treatment of hypoglycaemia.
A reduction in sucrose must however also be considered in overweight children.
Dietary Fats Dietary fat intake and the fatty acid composition are important in diabetes because of the associations with cardiovascular disease. The dietary
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recommendations for fat and fatty acids have been formulated for adults (18) but not separately for children.
Therefore the intake of children above 5 years should follow the DRVs for adults.
Up to the age of 5 years it is expected that the proportion of energy derived from dietary fats will fall from about 50%, as supplied by breast feeding or infant formula, to those recommended for adults.
This change should not occur before 2 years old.
In practice this means that the change from whole fat milk to semi-skimmed or even skimmed milk should be delayed until the age of 2.
Below this age a high energy density of foods is important, and in addition if low-fat foods are given to toddlers there can be associated rapid gastric emptying and diarrhoea.
Saturated Fatty Acids A diet low in saturated fat can lower total and low-density lipoprotein (LDL) cholesterol (28), which are strong predictors of coronary heart disease.
In European adults with Type 1 diabetes, the saturated fatty acid intake represents 14, 17% of total energy (29).
In children without diabetes it is 14 (22) and although at the lower end of the adult range, it is above the 10, 11% of dietary energy recommended (1,2,3,18).
These figures support the view that children as well as adults require greater practical advice on reducing saturated fat intake.
Polyunsaturated Fatty Acids (PUFAs) The DRV for PUFAs is 6.5% (18); WHO recommendations for the general population are 3, 7% (18) and the ISPAD Consensus Guidelines 2000 (1) for children with diabetes are <10% of total energy.
Cis polyunsaturated fatty acids can be divided into two main groups, cis n-3 and cis n-6.
These groups have different beneficial biological functions and are found in different foods.
Fish oils are the richest source of cis n-3, with seed oils and margarines also providing alternative sources.
Cis n-6 polyunsaturated fatty acids are found mainly in plant oils, including soya, corn and sunflower oils, and margarines manufactured from these oils.
In the UK childhood population the average total intake of energy from cis polyunsaturated fatty acid is 6% (22).
For infants, children and adults the DRV recommendations (18) are that linoleic acid (cis n-6) should provide at least 1% of total energy and a-linolenic acid (cis n-3) at least 0.2% of total energy.
A report on nutritional aspects of cardiovascular disease (30) recommended that no further increase in average intakes in respect of cis n-6 was required but cis n-3 should increase from around 0.1 g a day to 0.2 g.
Data are not available for individual fatty acids intakes for the general childhood population, however intakes of total cis n-3 and cis n-6 are above the DRVs set for individual fatty acids (22), suggesting that young people meet the DRV levels.
Guidance with emphasis on a good balance of both cis n-3 and cis n-6
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seems appropriate, as encouraging moderate intakes of these polyunsaturated fatty acids in a mixed diet will in consequence help to reduce overall saturated fat intake. Supplementation is not recommended as evidence of any benefit is conflicting on LDL cholesterol or glycaemic control.
Cis Monounsaturated Fatty Acids (MUFAs) Ideally most dietary energy should be derived from a combination of cis MUFAs (13% of total energy) and high soluble-fibre carbohydrate.
High MUFA intakes have several potential metabolic advantages including improving insulin sensitivity, glycaemic control and possibly reducing atheroma (28).
A major benefit of a higher MUFA diet is palatability and aiding compliance to an otherwise low-fat diet.
Donaghue et al. (31) have shown that even a modest increase in monounsaturated fat in adolescents with Type 1 diabetes seemed to improve insulin sensitivity.
The mean MUFA intake for the childhood population without diabetes is 11.8% of total energy (22).
The intakes of children with diabetes are likely to be similar, however sources of MUFA in the UK are not as readily available as in other European countries, particularly some of the Mediterranean countries.
Practical advice to increase MUFA intake should include promoting olive oil or rape seed oil and other rich sources such as specific margarines with a high monounsaturated fat content.
Trans-isomer Fatty Acids Some trans-isomers of PUFAs occur naturally but most are formed during partial hydrogenation of vegetable oils to produce margarines and vegetable shortening found in baked goods and pastries. The trans-isomers of PUFAs have similar detrimental metabolic effects as saturated fatty acids and for practical purposes should be considered the same. The present mean intake of children without diabetes is 1.4% of total energy (22).
Lower Fat Snacks The school snack, mid-morning, is often the most difficult one of the day, as it has to be taken or bought at school, carried in the school bag, and most importantly acceptable to peer group scrutiny.
In the UK this often allows for few healthy alternatives as children do not want to eat fruit in front of their friends, in other European countries this is less of a problem as children usually choose much healthier snacks (32).
Nevertheless dietary education should centre on lower fat snacks that are familiar to children.
The fat content of snacks such as fruit or a bag of crisps can range from 0, 12 g fat per portion, respectively, with similar carbohydrate values.
The lower fat products such as
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corn chips, potato sticks, etc. should be encouraged and discussed with the child to help them in selection. Pictorial illustrations are often useful.