Archives ofDisease in Childhood 1996; 74: 81-87

PERSONAL PRACTICE

Nutritional management of cystic fibrosis

Anita MacDonald

Nutritional support in cystic fibrosis hasachieved a new importance. First, nutritionalintervention is associated with better growthland improvement or stabilisation of pulmonaryfunction.23 Second, malnutrition has manyadverse effects on pulmonary function includingdecreased ventilatory drive, impaired pulmonarymuscle function, decreased exercise tolerance,and altered pulmonary immune response.4Third, there is evidence from a comparison oftwo North American clinics with very similarcare programmes, differing only in theirapproach to nutrition, that a high energy and fatdiet was associated with better growth andimproved survival.5The nutritional problems in cystic fibrosis

are multifactorial, and include increases inintestinal losses, energy requirements, andurinary glucose losses. One or more factorsalmost invariably coexist in combination withan inadequate energy intake. Malabsorption incystic fibrosis occurs mainly as a result ofmaldigestion secondary to pancreatic insuffi-ciency, which is rarely normal despite improvedpancreatic enzyme preparations. In addition,abnormal bile salt metabolism, liver disease,mucosal absorptive abnormalities and shortbowel syndrome, after intestinal resection inthe neonatal period, may all contribute.Murphy et al have estimated that stool energylosses account for 10% of gross energy intakein cystic fibrosis patients, three times higherthan normal.6

Although patients with moderate lungdisease may have a comparable total dailyenergy expenditure to controls,7 resting energyexpenditure has been shown to be increased bybetween 9%8 and 30%.9 This is related to theincreased work ofbreathing, lung infection andinflammation, enteral feeding, and drugs suchas salbutamol. A primary defect at a cellularlevel has been suggested,'0 although this isdisputed." Antibiotics have been shown toreduce energy requirements of moderatelyill cystic fibrosis patients with chronic

Dietetic Services, TheChildren's Hospital,Ladywood Middleway,BirminghamB16 8ET

Correspondence to:Mrs MacDonald.

Pseudomonas aeruginosa. '2 Diabetes, ifundiagnosed or inadequately controlled mayincrease energy losses due to glycosuria.Further substantial nutrient losses may occur

in the sputum, which have been estimated byWootton et al to be up to 1-5% of gross energyintake and up to 14% of total nitrogen losses. 13Sodium losses are important, and subclinicalsalt depletion can result in growth impairment,particularly in infancy.14

Dietary assessments show that patients withcystic fibrosis rarely exceed the estimatedaverage energy requirement or daily recom-

mended amount (table 1). Factors associatedwith reduced appetite include chronic respira-tory infection, and other complications ofcystic fibrosis such as distal ileal obstructionsyndrome, and gastro-oesophageal refluxresulting in oesophagitis, pain, and vomiting.'5Media pressure to eat a healthy, low fat, lowsugar diet, inappropriate concepts regardingbody image, 16 poor use of dietary supplements,behavioural feeding problems, particularly intoddlers, lack of financial resources and a

dislike of fatty foods all contribute to a reducedfood intake.17There is now sufficient evidence to warrant

energetic implementation of nutritional treat-ment in cystic fibrosis, and most centres utilisethe skills of a specialist paediatric dietitian andnutritional care team to provide nutritionalsupport to their patients. It is known thatprognosis in cystic fibrosis is better in largecentres,'8 and it is likely that changes innutritional support and diet have contributedto this.

Monitoring nutritional statusDIETARY ASSESSMENTIn the cystic fibrosis unit in Birmingham, thedietitian conducts an annual assessment ofnutritional intake using a three day prospectiverecorded diet diary, using household measure-

ments with supplementary information collected

Table 1 Energy intake of cystic fibrosis patients on a normal diet in the UK

Buchdahl et al (1989)70 Wootton et al (1990) 13 Morson et al (1994)71No of patients studied 20 30 50Age range (years) 5-3-17-3 53-16-0 0-75-25Energy intake of the respective RDI (%)* 99 92 97Range (%) 67-133 - 57-169Mean daily fat intake (g) 73 76Range (g) 36-133% Fat energy 30 36 34

*RDI=recommended daily intake.

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by a 24 hour retrospective recall diet history atthe routine clinic visits. Although these methodsare not entirely accurate, they give a useful guideto energy intake, nutrient profile, feedingroutines, types of foods eaten, and changes indietary pattern.

ANTHROPOMETRYSerial data on height and weight, expressed asweight and height for age, weight for height zscores, and head circumference in the first twoyears, are plotted. Serial measurements oftriceps skinfold thickness and mid-armcircumference are used as a way of assessingbody fat and lean body mass.

MALABSORPTIONThe gold standard to obtain an estimate ofthe degree of malabsorption is a faecal fatestimation, it is the method of choice, and issuccessfully used by many cystic fibrosisclinics. Unfortunately, the difficulties in per-forming this investigation have rendered itimpractical for routine use in our clinic. Thefaecal fat measurement should be conductedin combination with diet diaries to obtainestimates of fat intake and therefore fat absorp-tion. It is also useful for parents to recordpancreatic enzyme dosage, method of adminis-tration and timing, together with a symptomdiary collecting information about abdominalpain and stool frequency. An alternative andsimple way of assessing fat malabsorption inyoung children is the modified steatocrit pro-cedure described by Lloyd and coworkers.'9We have found it particularly helpful forserially monitoring changes in fat malabsorp-tion when adjusting pancreatic enzymesdosage in infants and young children.

Biochemical monitoringAnnual assessment of blood concentrations ofvitamins and minerals such as vitamin A,vitamin E, zinc, and iron which have beenreported to be low in cystic fibrosis is import-ant. Albumin and prothrombin times are alsoroutinely measured. Although deficiency oftrace minerals such as selenium have beendocumented,20 most recent research wouldsuggest that selenium status is satisfactory, andwe do not routinely monitor this.2'

Nutritional requirementsThe nutritional requirements of cystic fibrosispatients are ill defined. Cystic fibrosis is asyndrome with variable expression and soenergy requirements will differ according tothe clinical state as well as age, sex, andactivity of the individual. Although it is com-monly recommended to advocate an energyintake of 120-150% of estimated averagerequirements, it is our practice to assess andclosely monitor energy intake and equate thisto the nutritional status of the patient. Ifweightgain or growth is poor, the usual energy intakeis increased by a further 20-30% of total intake

by encouraging liberal quantities of fat(35-45% of energy intake) and sugar. Parentalconcern is often expressed about the effect ofdietary fat on blood lipids. It is reassuring toknow that adults with cystic fibrosis andpancreatic insufficiency eating a fat intakeproviding 34-35% of total energy intake havelower mean plasma cholesterol concentrationsthan controls. It is only pancreatic sufficientpatients who have lipid levels in the highnormal range.22 Fifteen per cent of the totalenergy intake is given from protein tocompensate for excessive loss of nitrogen in thefaeces and sputum.

Nutritional supportIt is custom to provide three levels ofnutritional support in our cystic fibrosis clinic.These include: (1) a high energy/high proteindiet; (2) dietary supplements; and (3) enteralfeeding.

(1) HIGH ENERGY/HIGH PROTEIN DIETWe encourage an energy and protein densediet giving foods such as full cream milk, fullfat cheese, meat, eggs, full fat margarine orbutter, bread, and cream. Although the princi-ples are simple, it is important that the diet istailored to the individual and carefully con-siders lifestyle, clinical condition, nutritionalstate, family circumstances, dietary beliefs andattitudes, food fads, appetite, and activitylevels. Nutritional counselling should alwaysbe age appropriate and we develop educationprogrammes with the aid of information book-lets, games and other teaching materials foreach patient to meet changing dietary needs.Specific attention is focused on involving thechild with cystic fibrosis in discussions aboutfood and achievable dietary goals are set andagreed in consultation with the child andparents at each clinic visit.

Parents are encouraged to adopt normalfeeding routines, limit meal times to a maxi-mum of 30 minutes, and develop consistentfeeding strategies and above all, remain posi-tive if food is refused. It is our experience thatexcessive focus on food, feeding, and weightgain can lead to abnormal feeding patterns andnegative feeding behaviour in cystic fibrosischildren.23 McCollum and Gibson reportedthat 37% of 65 children with cystic fibrosisover 1 year experienced feeding difficulties.24Many factors may precipitate food refusal,including parental anxiety about food, acuteinfections, frequent disruptions due to hospitaladmittance, and vomiting and gagging associ-ated with coughing spasms.25 In practice,reports of prolonged mealtimes, vomiting andgagging, constant parental nagging, and forcefeeding indicate that additional support onfeeding behaviour management is needed. Ifsimple dietary advice and reassurance fails,enlisting the help of a psychologist with aninterest in feeding problems is invaluable.There is some evidence to suggest that shortterm behavioural management programmesresult in improvements both in nutritional

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Nutritional management of cystic fibrosis

Table 2 Useful dietary supplement for children in cysticfibrosis

Energy,' Protein!100 ml 100 ml(kcal/kJ7) (g)

Fortified milk shakesFresubin (Fresenuis) 100/420 3-8Ensure Plus (Abbott) 150/630 6-3Fortisip (Nutricia Clinical Care) 150/630 5 0Entera (Fresenius) 150/630 5-6

Fortified fruit juicesFortijuice (Nutricia Clinical Care) 125/525 2-5Provide (Fresenius) 60/252 3-6

Glucose polymers/drinksSuper Soluble Maxijul (SHS) 360/1512 -Caloreen (Clintec Nutrition) 400/1680 -Polycal (Nutricia Clinical Care) 380/1596Iiquid Polycal (Nutricia Clinical Care) 246/1033 -Hycal (Beechams) 243/1021Iiquid Maxijul (SHS) 187/785 -

Fortified puddingsFormance (Abbott) 176/739 4-8

intake and nutritional status both in the shortand long term in a small group of children withcystic fibrosis.26 27

(2) DIETARY SUPPLEMENTSWe reserve use of dietary supplements forweight loss, any decline in height or weight z

scores (providing weight z score is no morethan 1 SD above height), if the quantity ofnutrient intake is below dietary referencevalues, or during acute chest infections. Therange and type of Advisory Committee forBorderline Substances prescribable dietarysupplements have improved in recent years.Three main types are available: (i) nutritionallyfortified milk shakes providing 1 0 kcal/ml and1-5 kcal/ml, (ii) glucose polymers, and (iii)nutritionally fortified desserts. The suitablesupplements we have found most useful forchildren are summarised in table 2.Unfortunately, there are few published data todemonstrate efficacy of dietary supplements incystic fibrosis and if excess quantities are usedthey are likely to reduce the intake of normalfood. The quantity recommended is agedependent and the following is a guide of howmuch we aim to give daily: 1-2 years, 200 kcal(840 kJ); 3-5 years, 400 kcal (1680 kJ); 6-11years, 600 kcal (2520 kJ); over 12 years, 800kcal (3360 kJ).

(3) ENTERAL NUTRITIONEnteral feeding is initiated when oral methodsof maintaining nutritional status have failedand substantial deviation from normal weightgain or growth occur. Enteral feeding is con-sidered in our clinic if a child is persistently lessthan 85% expected weight for height, or hasfailed to gain any weight over a three to sixmonth period. Only 5% of our cystic fibrosisclinic of 360 children need enteral feedingand the majority are teenagers, reflecting thedeterioration in nutritional status which occursin adolescents with cystic fibrosis. Enteralfeeding is associated with improvements inbody fat, height, lean body mass and musclemass, increased total body nitrogen, improvedstrength, and development of secondary sexualcharacteristics. To produce lasting benefit,numerous studies have demonstrated that

enteral feeding should be continued longterm.28-30 However, Dalzell and coworkersdemonstrated significantly greater height andweight scores in a group of 10 cystic fibrosischildren four years after cessation of tubefeeding after one year.4We have experienced occasional failures

with enteral feeding and it is not withoutcomplications. It may take up to six monthsbefore there is an increase in linear growthvelocity, weight gain may be disappointingeven two to three months after starting feeds,and the weight/height ratio is rarely returned tonormal. We have found that adolescent girlswho improve their nutritional status on enteralfeeds do not necessarily improve their image orself concept.16 Furthermore, daytime appetiteis almost always diminished and commoncomplications include vomiting, nasogastrictube dislodgement, gastrostomy tube block-age, leakage around the gastrostomy tube orbutton site. Gastro-oesophageal reflux iscommon in cystic fibrosis, and we have foundthis a problem in a small number ofpatients onnasogastric or gastrostomy feeding. Scott et alstudied eight patients on overnight continuousnasogastric feeds and although episodes ofreflux increased significantly, there was noincrease in percentage time oesophageal pHwas less than 4 and no evidence of aspiration ordeterioration in lung function.31

It is our practice to give enteral feeding for8-10 hours overnight with a 1-2 hour breakbefore the first physiotherapy in a morning.Allowing teenagers to have one or two nightsoff the feed each week helps compliance. Atleast 400/o-50% of the estimated energyrequirement is usually given via the tube, butwe review the feeding regimen and anthropo-metric measurements monthly and the feedcomposition is adjusted if nutritional status isnot improving. Thirty per cent of our patientshave developed hyperglycaemia requiringinsulin treatment since starting enteral feedsand we have seen hyperglycaemia in a 4 yearold child on overnight feeds. It has beenreported that up to 64% of adult patients onenteral feeds experience hyperglycaemia whichwas managed with small doses of short actinginsulin.32 Consequently, when starting enteralfeeding and on subsequent hospital admis-sions, or if weight gain is poor, four hourlyblood glucose profiles are monitored for 24hours.

For most cystic fibrosis patients over 20 kgwe find an energy dense polymeric feed provid-ing at least 1-5 kcal/ml (6-3 kJ/ml) such asFortisip (Nutricia) or Ensure Plus (Abbott) iswell tolerated. For children weighing less than20 kg it is better to give a polymeric paediatricfeed such as Nutrison Paediatric or Paediasureproviding 10 kcal/ml as the protein andnutrient profile has been developed especiallyfor the younger age group. Some centres in theUK still prefer to use an elemental chemicallydefined formulas for enteral feeding in cysticfibrosis. In theory, elemental feeds have a goodbuffering effect on gastric acidity at night,3 andare better absorbed. Some centres do not givepancreatic enzymes with elemental feeds but

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this would be disputed by some. Elementalfeeds are generally lower in fat, but they usuallycontain a mixture of medium and long chaintriglyceride fats. They are also expensive, havea high osmolality and a low energy density.Although there is little work comparing theefficacy of elemental versus polymeric feeds incystic fibrosis, one study demonstrated thatsteatorrhoea is no greater using polymericformula in combination with pancreaticenzyme supplements than an elemental feed.33High fat feeds such as Pulmocare (Abbott)may have a role in cystic fibrosis for patientswith severe lung disease as they result inless carbon dioxide production and lowerrespiratory quotient.34The best way of giving pancreatic enzymes

with tube feeds is not known. Although currentpractices vary widely, we divide the dose intotwo portions and give them at the beginning ofthe feed and just before the patient goes tosleep. No method has been shown to besuperior. Dosage of pancreatic enzymes withenteral feeds is arbitrary but can be estimatedby using the amount of pancreatic enzymesrequired for a normal meal and adjusting thequantity in accordance with the fat composi-tion of the feed. The choice of route used forenteral feeding is influenced by the duration offeeding and by the preference of the patientand relatives. We have had equal success withboth nasogastric and gastrostomy feeding, andbefore feeding is started families are counselledon the relative merits and drawbacks of bothsystems. Many patients initially start naso-gastric feeds but usually proceed to gastros-tomy feeding when they have realised thebenefits of enteral feeding and appreciatefeeding is long term.

Vitamin and mineral supplementsFAT SOLUBLE VITAMINSLow serum vitamin A concentrations. arecommonly reported in cystic fibrosis anddocumented clinical features of vitamin Adeficiency include night blindness,35 conjunc-tival and corneal xerosis,36 dry thickened skin,and abnormalities of bronchial mucosalepithelialisation.37 For many years we havegiven supplementation of up to 2400 ,ug (8000IU) to 3000 pug (10 000 IU) of vitamin A dailyin the form of 1-2 ml Abidec (Paines andByrne), Dalivit, or two vitamin A and Dcapsules. However, vitamin A supplementedcystic fibrosis patients are known to havenearly a 3-5-fold hepatic vitamin reserve thannormal controls. Hypervitaminosis has beenreported in an infant with cystic fibrosis afterexcessive vitamin A supplementation38 and inan adult supplemented with 10000 IU ofretinol palmitate.39 There is some suggestionthat accumulation of vitamin A in the liver,despite low serum concentrations may lead tohepatic toxicity with long term high dosevitamin A supplementation.40 Vitamin Astatus and supplementation warrants furtherinvestigation in cystic fibrosis.A neuropathy due to vitamin E deficiency

has been widely reported in adult cystic fibrosis

patients. Symptoms and signs include absentdeep tendon reflexes, loss of position sense andvibration sense in the lower limbs, dysarthria,tremor, ataxia and decreased visual activity.Almost all cystic fibrosis centres now give rou-tine vitamin E supplements and the usualrecommended daily doses are 50 mg ininfancy, 100 mg in 1-10 year children, and 200mg for teenagers. Both water miscible and fatsoluble preparations of vitamin E are effectivein achieving normal serum concentrations.4'

Decreased bone mineral density42 andosteopenia, associated with low 25-hydroxy-vitamin D levels43 have been described in adultpatients with cystic fibrosis. Rickets is rarelyseen in childhood, although subclinical con-centrations of vitamin D metabolites have beenreported. A daily supplement of 20 ,ug/day(800 IU) of vitamin D is given to all agegroups.

MINERALSNormally there appears no need to recom-mend additional sodium, but salt depletioncan occur in hot weather, through physicalexercise causing increasing sweating and ininfancy if an infant is on a normal lowelectrolyte formulas such as SMA Gold (SMANutrition) or Nutrilon Premium (Cow andGate). Anorexia and poor growth may resultfrom chronic salt depletion. Significanthyponatraemia may be accompanied byvomiting.We advocate routine salt supplements

during hot weather and in all infants on normalinfant formulas. The amount given is arbitrary,but the following is a useful guide: 0-6 months,2 mmollkg/day of sodium in the form ofsodium chloride solution (1 ml= 1 mmol);7-12 months, 1 mmollkg/day of sodium; 1-5years, 10 mmol sodium/day (2X 300 mgsodium chloride tablets); 6-10 years, 20 mmolsodium/day (2 X 600 mg sodium chloridetablets); and 11 years, 30-40 mmolsodium/day (3-4X600 mg sodium chloridetablets).

Pancreatic enzyme supplementsMost cystic fibrosis centres predominantly useenteric coated microspheres (Creon, Duphar;Nutrizym GR, Merck; Pancrease, Cilag) for allinfants and children, either administered asgranules or in a gelatin capsule. Enteric coatedmicrospheres should be able to achieve at least900/o fat absorption if administered in appro-priate dosages. Several studies have demon-strated that enteric coated microspheres aremore effective than conventional pancreaticpowder and enteric coated capsules.4"'6 Wehave found little difference between existingenteric coated microspheres when matchedcapsule per capsule,47 despite differing lipase,protease, and amylase content.

Initial results of studies using high lipaseenteric coated enzymes looked promisingindicating that dosage of enzymes may be ableto be reduced by up to 66%.48-50 However,high lipase pancreatic enzymes have been

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implicated as a possible factor in the aetiologyof colonic strictures which have occurred in asmall group of cystic fibrosis children.5'-53 As aresult of this the Committee on Safety inMedicines have recommended that cysticfibrosis patients are returned to ordinarystrength enteric coated pancreatic enzymesuntil a satisfactory explanation for thedevelopment of colonic strictures is found.

Administration and dosage of pancreaticenzymes can be difficult, particularly in infantsand young children. In infancy it is our experi-ence that enteric coated microspheres are bestmixed with a small amount of fruit puree,which holds the granules in a gel, and givenfrom a spoon at the beginning of the feed. Notall infants will accept enzymes this way and thegranules may stick between gums which maycause oral irritation, be spat out, or cause

gagging and choking. We recommend a start-ing dose of 0 5 capsule per 90-150 ml offormula feed or breast feed, although it isdifficult to measure proportions of capsuleswith any accuracy. In the toddler age group,pancreatic enzymes still need to be adminis-tered in the granule format. Unfortunately, inthis age group, the enteric coated granules are

particularly unpopular even when mixed withfavourite foods and enzyme refusal, coughing,choking, or even vomiting is common. Sometoddlers may chew the granules or hold themin their mouths for considerable periods oftime releasing the enzyme and predisposing tomouth ulcers. In this age group, it may bebetter to spread the enzyme dosage throughoutthe meal, so the dosage can be varied accord-ing to the volume and type of food consumed,even though there is evidence to suggest thatfat excretion is reduced in younger childrenwhen pancreatic enzymes are given beforemeals.54 It is difficult to administer pancreaticenzymes to a toddler and if simple behaviourstrategies such as praise, encouragement, andconsistency are ineffective, it may be helpful toenrol the help of a behavioural psychologist.

Unfortunately, if there is no objectivemeasure of fat excretion, arbitrary assessmentof enzyme dosage based on abdominal painand stool description can lead to overdosage ofpancreatic enzymes as it is assumed that allabdominal symptoms are invariably due topancreatic insufficiency. Firm guidelines areneeded in the UK on the daily upper limit ofpancreatic enzymes in relation to body weightand age. In the USA, Lenbenthal suggests thefollowing upper limits for lipase pancreaticenzyme dosage: 3000 units/kg/dose.55 ACommittee on Safety of Medicines WorkingParty investigating the use of pancreaticenzyme supplements and colonic strictureshave issued a preliminary recommendationthat doses in excess of 10 000 units oflipase/kg/day, irrespective of the preparation,should be avoided (M D Rawlins, personalcommunication).

Infant feeding in cystic fibrosisScreened and non-screened infants have beenshown to have nutritional problems at the time of

diagnosis. Failure to thrive, hypoalbuminaemia56and even kwashiorkor57 are seen in unscreenedinfants, whereas nutritional deficits in screenedinfants are more subtle, but include reducedbody mass, length, total body fat, total bodypotassium58 and low levels oftocopherol, linoleicacid,59 serum retinol, 25-hydroxyvitamin D,60and plasma carnitine.61 We find most infantswith pancreatic insufficiency will thrive on anormal energy intake of 100-130 kcal/kg inadjunct with pancreatic enzymes. If weight gainis less than expected or if a meconium ileus hasresulted in surgery and bowel resection, theenergy requirements may be as high as 150-200kcal/kg.We encourage breast milk for infants with

cystic fibrosis. It contains lipase, long chainpolyunsaturated fatty acids, provides someimmunological protection against infection,and may be psychologically better for themother. Infants on breast milk and pancreaticenzymes grow and gain weight appropriatelywith near zero z scores.62 One possible concernis the possibility of electrolyte depletion63 onthis low sodium milk and we administerroutine sodium supplements to all breast fedbabies (see mineral section), and monitorurinary electrolytes if weight gain is poor.Alternatively, infants with cystic fibrosis thrivesatisfactorily on normal infant formulas,64although like breast milk, electrolyte depletionis a possibility63 and we supplement routinelywith sodium supplements. Energy supplemen-tation of formula is only necessary if there islack of catch-up weight gain, weight loss, ordecline in weight z score. Glucose polymertogether with a long chain 50% fat emulsion,for example, Calogen (SHS) are used. Theaddition of 5 g glucose polymer and 3 ml ofa 50% fat emulsion/100 ml of normal infantformula provides approximately 100 kcal/100 ml.Although protein hydrolysates are favoured

for infants with cystic fibrosis in the USA,65 wewould only use these formulas if an infantdevelops a temporary disaccharide intoleranceafter surgery for meconium ileus. Theseformulas appear to have no advantages incystic fibrosis, are expensive, and should stillhave pancreatic enzymes administered withthem.66

Diabetes and cystic fibrosisGlucose intolerance and diabetes mellitus iscommon in cystic fibrosis. The incidence ofdiabetes mellitus may be as high as 8%/o-15%and this increases with age,67 although it hasbeen reported in children as young as 2 years.68The diabetes is non-ketotic, has a slow onset,but is usually insulin dependent. An insidiousdecline in overall clinical status often occursbefore diagnosis of diabetes is made.69No clear guidelines have been issued on ideal

dietary management for patients with both cys-tic fibrosis and diabetes, although advice shouldbe tailored according to the severity ofthe cysticfibrosis. Providing optimal nutrition for the cys-tic fibrosis patient is still of paramount impor-tance and any dietary restriction should be

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minimised. We still advise a high fat and carbo-hydrate intake. However, we do if possibleencourage sugar free soft drinks, exchangeglucose polymer supplements for fortified milksupplements, and some unrefined carbohydrateis given at regular meals, snacks, and bedtime.With the exception of drinks, simple sugars arenot prohibited, but intake is encouraged along-side unrefined carbohydrate. Diabetic control isimproved by alterations in insulin treatmentrather than imposing dietary restrictions whichmay adversely affect nutritional status.

ConclusionNutritional support is an integral part of themanagement of cystic fibrosis patients. It isarguably best provided by a qualified dietitianand nutritional care sister working in conjunc-tion with the rest of the cystic fibrosis team.The patient's nutritional needs should beassessed, regularly reviewed, and nutritionaltreatment tailored to meet the changingclinical and psychosocial needs of the patient.Nutritional intervention is not without compli-cations, and in particular attention to normalfeeding behaviour and vigilance when institut-ing supplementary nutrition may prevent manyfeeding difficulties.Grateful thanks are expressed to Dr P H Weller, Dr D ASpencer, and Professor I W Booth for their help with thismanuscript.

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