After reading this chapter you should be able to assess, diagnose and manage:
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problems arising during the establishment of infant feeding regimes
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malnutrition, obesity and their complications
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specific vitamin, mineral and micronutrient deficiencies
The assessment of nutrition in paediatric practice requires an understanding of the requirements through the periods of growth and development along with an appreciation of the actual intake and content of fluids and foods. There is a need to recognise that energy, fat, protein, carbohydrate, vitamins and minerals must be sufficient to meet the changing needs of the growing child. Growth in the first year of life is rapid, particularly of the brain, and a normal infant requires around three times more energy per kilogram than an adult reflecting the added energy requirements needed for growth.
Infant feeding
Breast feeding
Breast milk is the most appropriate food for newborn infants and every mother should be encouraged and supported to establish this method of infant nutrition. No breast milk substitute can completely replicate the physiological role of breast milk as a source of nutrition and immunoprotection, and the inappropriate use of breast milk substitutes remains one of the most important worldwide causes of preventable mortality in infancy.
The UK has one of the lowest rates of breastfeeding in Europe although the trend is towards an improvement in uptake, and the most recent UK figures for 2019/2020 report that 48% of mothers are breastfeeding at 6–8 weeks. These rates, however, fall over the following weeks and months such that only about 30% of infants are receiving breast milk at 6 months. The prevalence of breastfeeding is particularly low among very young mothers and disadvantaged socioeconomic groups.
Women most commonly give up breastfeeding early due to perceptions that they are failing to provide adequate nutrition for their child. Confidence in breastfeeding is severely undermined when supplementary formula milk feeds are recommended by health care staff and supplementation is strongly associated with secondary lactation failure and premature cessation of breastfeeding in mothers. Many maternity units operate a nonformula supplementation policy (a fundamental component of the UNICEF Baby Friendly Initiative) and medical staff should actively support this approach.
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approximate content per 100 ml; carbohydrate 7g; fat 4g; protein 1.3g
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protein—70% whey, 30% casein (whey is easier to digest; cow’s milk is 80% casein)
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protein—lactoferrin, lysozyme, secretory IgA—role in host defence
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carbohydrate—lactose and oligosaccharides
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fat—triglycerides, essential fatty acids, sterols and phospholipids
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enzymes that aid digestion (e.g., lipase) and may also be bactericidal (e.g., lysozyme)
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vitamins and minerals
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growth factors—insulin-like factors; epidermal growth factors
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immunological factors; leukocytes; macrophages; stem cells; IgA; lactoferrin
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Prebiotics including human milk oligosaccharides
Formula feeding
For some mothers, breastfeeding may be contraindicated, and some may elect to use formula feeds. These milks must meet the current UK laws pertaining to formula and follow-on milks that define their composition and marketing. These laws clarify that the essential composition of these formula milks ‘must satisfy the nutritional requirements of infants in good health, as established by generally accepted scientific data and that the labelling allows the proper use of such products and promotes and protects breastfeeding’.
All formula milks recommended for general use are made from modified cow’s milk. Whey-based infant formulae (‘first milks’) are all that is required for the first year of life. Manufacturers are keen to promote casein-dominant formulas (‘second milks’) which are nearer to cow’s milk as this requires less modification, but they are less physiologically similar to breast milk. Mothers should be advised to continue whey-based formulae until the child switches to full-fat whole cow’s milk after the age of one.
Alternative milks and their clinical indications
The range of alternative milks is extensive and are proposed for a range of differing indications. Those available include:
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extensive hydrolysed formula—first-line treatment in both IgE and non-IgE cow’s milk protein allergy
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amino acid formula—second-line treatment in both IgE and non-IgE cow’s milk protein allergy under guidance from paediatric and dietetic colleagues
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soya-based formula – not recommended for infants under 6 months of age due to phytoestrogen levels. Can be used in older infants with cow’s milk protein allergy when other formulas are rejected for palatability and may be chosen by families practicing veganism
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lactose-free formula—for secondary lactose intolerance (true lactose intolerance is very rare in babies)
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anti-reflux formula—thickened formula for regurgitation. Other causes for regurgitation should be ruled out and it may be contraindicated with certain anti-reflux medication which also thicken feeds
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low birthweight formula—for preterm infants typically born less than 35 weeks gestation
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high energy formula—for infants with increased energy requirements or fluid restrictions such as those with cardiac or pulmonary abnormalities
Goats’ milk formula is compliant with current UK regulations but is no less likely to cause allergies than cows’ milk formula due to a high level of cross-reactivity. Other milks available include ‘hungry baby formula’, comfort formula and follow-on formula but formal assessment does not reveal any significant benefits in using these milks for the problems described.
Complimentary feeding
This is also known as weaning and refers to the process by which solid foods are gradually introduced to the diet. The current UK advice to parents is that this should start around 6 months and not before 4 months corrected gestational age. It is recommended that all food groups be introduce to infants even if there is a history of atopy or a high risk of food allergy. Salt and sugar should not be added to solid food for infants.
Assessment of nutritional status
Accurate growth monitoring is a fundamental component for assessing the health, development and nutritional status of infants and children as disturbances in health and nutrition, regardless of their aetiology, almost always affect growth. Dietary assessment cannot be safely used to diagnose poor nutrition although food diaries can provide help and information about the range and type of food eaten and they act as a guide to dietary advice once the problem has been identified. The more comprehensive assessment of nutritional status requires information from the history and examination along with the plotting of growth parameters on population-based charts appropriate for patient characteristics.
Weight, height (or length) and body mass index (BMI) provide a measure of nutritional status. These features should be accurately measured and plotted over time as it is important to incorporate more than one measurement for a complete assessment. BMI must be interpreted in the light of body habitus as an athletic teenager may have a high BMI value due to increased muscle bulk. Head circumference is measured in infants and toddlers up until the age of 2 years. Recumbent length is measured in infants and toddlers under the age of 2 years and beyond this age their height is measured. Mid-upper arm circumference measurements are also used to assess nutritional status particularly in more rural settings where anthropometric equipment is not available or in medical conditions where weight and height measurements are inaccurate such as those with renal disease, liver disease or cerebral palsy.
All anthropometric measurements should be plotted on the correct corresponding growth chart and documented in the clinical notes.
Growth charts
Growth is an important indicator of health for infants and children, and growth charts provide a way to objectively assess and monitor growth from birth to 18 years of age, depending on the growth chart used.
The WHO growth standards describe optimal growth for healthy, breastfed (i.e., exclusively breastfed from 0–6 months of age) children from 0 to 5 years of age. As breastfeeding is considered the gold standard form of nutrition for infants, these data are regarded as a standard, rather than a reference. The most common growth charts used in countries around the world rely on local and WHO data on growth. Condition-specific growth charts are available for individuals with Down syndrome, Turner syndrome, homozygous sickle cell disease and Williams syndrome.
The use of growth charts allows the identification of individuals whose measurements lie some distance from the population mean using centile lines or, in some situations, z-scores. The latter are statistical scores that relate directly to standard deviations from the mean of the growth parameter under review. Z scores are particularly useful when growth measurements are at either extreme of the centile chart.
Malnutrition (undernutrition)
Faltering growth (previously known as failure to thrive) refers to a slowing of weight gain in childhood that is less than expected for age and sex. It is not a diagnosis but describes a problem and denotes the need to investigate and determine the aetiology. Faltering growth can be acute (present for less than 3 months) or chronic (present for more than 3 months). Early detection and simple interventions to increase nutritional intake can help prevent acute faltering growth becoming a chronic condition.
Malnutrition (undernutrition) is defined as an imbalance between nutrient requirements and intake that results in cumulative deficits of energy, protein or micronutrients that may negatively affect growth, development and other relevant outcomes. The term therefore describes undernutrition (inadequate intake) and poor nutrition (inappropriate intake) of calories and required nutrients and the term malnutrition will be used here to include both concepts ( Table 6.1 ).
| Moderate | Severe | |||
|---|---|---|---|---|
| acute | chronic | Acute | chronic | |
| BMI | 0.4 – 9th | less than 0.4 | ||
| length or height | 0.4 – 9th | less than 0.4 | ||
Observations in the table refer to centile ranges. The impact of chronic malnutrition leads to stunting.
The paediatric population is at higher risk of malnutrition-related complications such as poor wound healing, higher risk of infection, delayed recovery, prolonged hospitalisation and developmental delay. This is due to infants and children having a lower energy reserve and the higher nutritional requirements needed for growth.
When a child is assessed for suspected faltering growth, a thorough clinical, developmental and social assessment should be conducted that includes anthropometry, nutritional intake and output and gastrointestinal symptoms. Initial assessment should look for evidence of dehydration or of an illness or disorder that might account for the weight loss. Other invasive investigations are only necessary if clinical symptoms or signs exist. Concern and further investigations are warranted if a newborn infant, younger than 2 weeks of age, loses more than 10% birthweight or does not regain birthweight within the first 7 to 14 days of life.
In infants and older children, faltering growth is usually defined as weight for age falling across two or more weight centiles. A BMI between 0.4 and the 9 th centile is considered unusual and may reflect moderate malnutrition (undernutrition— Figure 6.1 ), but genetic factors such as a small build should be considered. A BMI less than 0.4th centile is considered outside the normal range and severe malnutrition can be diagnosed.
