Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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Advantages of Breast-Feeding

0017 There are numerous advantages of breast-feeding,

including nutritional, emotional, physiological, and

economic factors. Breast-feeding guarantees regular

close contact between mother and child, promoting

the emotional bonding process.

0018 Many of the nutritional advantages of breast milk

have already been discussed. In summary, milk from a

healthy mother provides all the nutrients in an appro-

priate and easily absorbable form to meet the require-

ments of the infant.

0019 Additionally, this feeding method is cheap, safe,

and offers anti-infective advantages. Cross-infection

from adults to the infant may be reduced; as only the

mother is able to breast-feed, the number of adults

handling the child may be reduced. Breast-feeding is

convenient, as the milk will always be available at the

correct temperature and ready to feed. The mother

does not need to buy equipment, sterilize bottles and

teats, or prepare infant formula in hygienic condi-

tions. Many constituents in human breast milk stimu-

late the development of the infant’s own immunity.

Through the milk the mother is able to transfer to her

infant antibodies (IgA) which are specific antigens

against their environment. This fills the ‘immunity

gap’ whilst the infant’s immune system develops and

its gut epithelial cells mature to be able to produce

IgA. Other important defenses include macrophages

(ingest foreign particles), lactoferrin (bacteriostatic),

milk leukocytes (phagocytosis of bacteria, viruses,

and fungi) and lysozyme (bactericidal and anti-

inflammatory activity). Whilst the baby’s own

immune system matures, these bioactive milk con-

stituents act synergistically to provide a passive

immunological support system for the infant.

0020 Epidemiological evidence suggests that breast-

feeding has a protective effect against diarrhea, re-

spiratory infections, necrotizing enterocolitis, and

otitis media. Research has recently focused on pos-

sible links between infant feeding practice and

chronic illness such as Crohn’s disease and childhood

lymphoma in later life. The American Academy of

Pediatrics reviewed feeding method and incidence of

type 1 insulin-dependent diabetes mellitus (IDDM). It

recommended breast-feeding as the main source of

infant nutrition and avoidance of intact cows’ milk

protein in the first year of life if there is a strong

family history of IDDM.

0021 The role of breast-feeding in protecting the infant

against the development of atopic and allergic dis-

orders in later life is controversial. Further research is

needed in this area. It is hypothesized that the immuno-

logical factors in breast milk may protect the infant

from absorbing intact allergens. Breast-feeding results

in delayed exposure to many allergenic compounds in

foods. However, components of the mother’sdietmay

be passed to the infant via breast milk. The role of

maternal exclusion diets in exclusive breast-feeding

for high-risk infants is also controversial. Allergy to

peanut is potentially life-threatening and for this

reason, in the UK, the Committee on Toxicity of

Chemicals in Food, Consumer Products and the Envir-

onment has suggested that pregnant and lactating

women should avoid peanuts if they themselves, the

father, or any sibling of the baby is atopic.

0022Enhanced cognitive development is associated with

breast-feeding. The role of LCPs in breast milk and

infant development has been the subject of recent

research. Docosahexaenoic acid (DHA) (C

:6n-3)

and arachidonic acid (C

:4n-6) are considered essen-

tial nutrients in early infancy. Dietary DHA appears

to be essential for optimal membrane function in the

nervous system and thus cognitive development in

premature infants. Many infant formulas now con-

tain added LCPs but other constituents of breast milk,

e.g., growth factor, hormones, and choline, may add-

itionally aid brain maturation.

0023Malnutrition can result from either the overcon-

centration or overdilution of infant formulas. There

is no risk of this with breast milk. Breast-feeding is

linked with child survival in developing countries due

to its protective effect against diarrheal illness, envir-

onmental factors (e.g., lack of clean water supply),

and economic factors (e.g., expense of buying ad-

equate volumes of infant formulas).

0024It is known that breast-feeding has advantages for

maternal health. Breast-feeding stimulates contrac-

tion of the uterus. It is associated with weight loss

and thus a more rapid return to prepregnancy weight.

Some epidemiological evidence suggests a link be-

tween extended lactation and reduced risk of preme-

nopausal breast, ovarian, and endometrial cancers.

0025Lactation produces hormonal changes which sup-

press fertility. At the population level, this lactational

amenorrhea enables prolonged birth spacing. Add-

itionally, in some societies there are taboos against

sexual intercourse during the period of lactation.

Breast-feeding therefore has a major contraceptive

effect.

Reasons for Bottle-Feeding

0026There are few contraindications to breast-feeding;

the main reasons are related to the health and medica-

tion requirements of the mother. Maternal medication

usage may prevent breast-feeding. Most drugs can be

transmitted to the infant via breast milk. Drugs

may cause toxicity in the infant, e.g., ergotamine, and

others inhibit the suckling reflex, e.g., phenobarbitone.

3290 INFANTS/Breast- and Bottle-feeding

The British National Formulary is an important

resource for health professionals to check the suit-

ability of a medicine for breast-feeding women. UK

recommendations are that only essential medications

should be prescribed to breast-feeding mothers.

0027 There are certain medical conditions in the baby

where breast-feeding is contraindicated: galactose-

mia, long-chain fatty acid oxidation disorders, and

glucose-galactose malabsorption.

0028 Breast-feeding is known to protect against bacterial

infections. Certain viruses however can be transmit-

ted from mother to infant in breast milk. The largest

global health problem is related to human immuno-

deficiency virus (HIV) transmission via breast milk.

The rate of vertical transmission from mother to

infant in human milk is between 5 and 15%. In

England and Wales the incidence of vertically trans-

mitted HIV infection is increasing. In the UK the

current recommendation is that mothers who are

HIV-positive, or in a high-risk category but unsure

of their serological status, should not breast-feed.

Experts argue that if antenatal HIV testing was

more widespread, there would be an opportunity to

counsel against breast-feeding and insure early diag-

nosis and treatment of infected children.

0029 In the UK bottle-feeding is a safe alternative to

breast-feeding. In developing countries with high

infant mortality rates the situation is very different.

The known protective effect of breast-feeding against

gastrointestinal infection is very important. It has

been estimated that bottle-fed infants are 14 times

more likely to die from diarrheal diseases and four

times more likely to die from pneumonia than exclu-

sively breast-fed infants. In these countries the risk of

vertical HIV transmission needs to be weighed

against the risk of gastrointestinal infection caused

by inadequate water supply and sanitation. The

United Nations has recently issued a new directive

stating that all women should be informed of the

risk of vertical transmission via breast milk due to

the escalating problem of HIV. It recommends the

decision to breast-feed should be made by the mother

due to the diversity of situations in developing coun-

tries.

0030 There remain concerns that women who do not

breast-feed in developing countries may be stigma-

tized, and there are concerns over the safety of alter-

native feeds. Previously, infant deaths in developing

countries resulted from the problems of mixing infant

formulas in unsuitable environments. Recently it has

been hypothesized that rates of HIV transmission are

affected by mastitis infection and vitamin A defi-

ciency in pregnancy. A 1994 study of HIV-infected

women in Malawi found that 32% of those who were

vitamin A-deficient during pregnancy had passed

HIV on to their infants. In contrast, only 3% with

adequate vitamin A levels did so. If health strategies

are implemented to alter these states, breast-feeding

may be a recommended feeding method for infants of

HIV-infected women in the future.

0031In the UK women’s choice of feeding method is

influenced by social and cultural factors. The Office

for National Statistics identifies that 94% of mothers

have decided on feeding method antenatally. They

identified that 36% of the mothers surveyed in the

UK intended to bottle-feed. Reasons for planning to

bottle-feed included disliking the idea of breast-

feeding and embarrassment associated with breast-

feeding. In western societies taboos continue to be

associated with breast-feeding in public. The other

major reason for choosing to bottle-feed is that the

mother is not the sole feeder of the child, so other

people can help with the feeding.

Current Practices

0032Breast-feeding in developing countries remains

almost universal. It remains common in Africa for

most infants to be breast-fed into the second year of

life. As these countries become more urbanized,

breast-feeding trends alter. Generally, women in

rural areas are more likely to breast-feed than their

urban counterparts. This change may reflect the

availability of infant formula, limited support net-

works, and variations of maternal employment pat-

terns. The wealthiest and most highly educated in

developing countries are less likely to breast-feed.

The converse is true in developed countries. Immi-

grants’ feeding choice is affected by the norm in both

their country of origin and resident country.

0033In the UK, government policy consistently supports

the promotion of breast-feeding. Since the 1970s

infant feeding practices have been surveyed and

results analyzed, leading to Department of Health

initiatives to promote breast-feeding, e.g., National

Breastfeeding Awareness Week. This has been an

annual event since 1993. In 1995, the Office for

National Statistics survey reported an increased inci-

dence of breast-feeding (Table 2). The composition of

the sample population contained more mothers aged

over 30 from nonmanual social class groups and with

higher education levels. Each of these factors is asso-

ciated with increased incidence of breast-feeding.

When the results are standardized for the age and

level of education, no increase in breast-feeding inci-

dence in England and Wales is demonstrated. In

Northern Ireland, however, standardized rates in-

creased from 36% in 1990 to 41% in 1995.

0034The World Health Organization recommends ex-

clusive breast-feeding for at least 6 months. A reduced

INFANTS/Breast- and Bottle-feeding 3291

incidence of gastrointestinal infection is associated

with breast-feeding for a minimum of 13 weeks.

Results for the UK in 1995 showed that 20% of

women had stopped breast-feeding at 2 weeks post-

partum and 60% by the age of 4 months (Table 3).

Initiatives are clearly needed to improve the duration

of breast-feeding.

0035 Reasons for stopping breast-feeding included ‘in-

sufficient milk.’ This may be related to anxiety and

lack of professional support and advice. Establishing

breast-feeding is no longer instinctive in developed

countries. Painful breasts, baby not suckling, not

liking breast-feeding, and length of time taken to

feed were other common reasons for cessation of

breast-feeding.

0036 The mother’s experience of breast-feeding in hos-

pital influences its duration. The giving of infant

formula complementary feeds continues to exert a

strong effect on the length of breast-feeding. In

1995, 34% of mothers whose infants received a bottle

in hospital stopped breast-feeding within the first 2

weeks postpartum. Delays in first holding the baby

significantly affected the likelihood of establishing

breast-feeding. Only 51% of mothers who were

separated from their baby for more than 12 h success-

fully initiated breast-feeding. These issues are being

tackled by educating all health care professionals and

the adoption of UNICEF’s Baby Friendly Hospital

Initiative. Between the 1990 and 1995 Office of Na-

tional Statistics surveys, an increase in the number of

babies kept at the mother’s side at all times and the

reduction in the number of breast-fed babies offered

bottled formula during their hospital stay were seen.

This is an encouraging trend.

Education and Advice

0037The 1995 Office of National Statistics survey showed

that nearly all mothers (99%) had antenatal check-

ups and approximately 70% of new mothers attended

antenatal classes. These are ideal opportunities in

which to offer advice about feeding methods. The

survey also showed that either a midwife or nurse

gave 86% of new mothers help and advice at their

first breast-feed in hospital. During their hospital

admission, 35% of breast-feeding mothers experi-

enced difficulties. The majority of these women

(82%) received help and advice from health profes-

sionals and this has been shown to influence feeding

duration. As about one-third of first-time mothers

leave hospital within 48 h, access to professional sup-

port is restricted and potentially the declining lengths

of hospital postpartum stay may impact on initiation

and duration of breast-feeding.

0038After discharge from hospital, the mother is sup-

ported at home for the first 10 days by the midwife.

Care is then transferred to the health visitor. Add-

itionally several voluntary organizations can offer

support on breast-feeding; these include the National

Childbirth Trust, La Leche League and the Associ-

ation of Breastfeeding Mothers.

See also: Anemia (Anaemia): Iron-deficiency Anemia;

Atherosclerosis; Carotenoids: Occurrence, Properties,

and Determination; Celiac (Coeliac) Disease;

Cholecalciferol: Properties and Determination; Food

Intolerance: Food Allergies; Infant Foods: Weaning

Foods; Iron: Properties and Determination; Metabolic

Rate; Protein: Requirements; Retinol: Properties and

Determination; Rickets and Osteomalacia; Zinc:

Properties and Determination; Deficiency

Further Reading

Forsyth JS (1992) Is it worthwhile breast-feeding? European

JournalofClinicalNutrition46 (suppl. 1): S19–S25.

Foster K, Lader D and Cheesbrough S (1997) Office for

National Statistics – Infant Feeding 1995. London:

Stationery Office.

tbl0002 Table 2 Prevalence of breast-feeding (%) up to 6 months of age

by country

England and

Wales Scotland

Northern

Ireland

19 9 0 1995 19 9 0 19 95 19 9 0 19 9 5

Birth 64 68 50 55 36 45

2 weeks 51 54 39 44 27 32

6 weeks 39 44 30 36 17 25

4 months 25 28 20 24 8 12

6 months 21 22 16 19 5 8

Base (number of infants) 4942 4598 1981 1863 1497 1476

From Foster K, Lader D and Cheesbrough S (1997) Office for National

Statistics ^ Infant Feeding 1995. London: Stationery Office. Crown copyright

is reproduced with the permission of the Controller of Her Majesty’s

Stationery Office.

tbl0003 Table 3 Duration of breast-feeding (%) for mothers who

breast-fed initially in the UK

19 9 0 19 9 5

Birth 100 100

1 week 85 85

2 weeks 80 80

6 weeks 61 65

4 months 39 42

6 months 33 32

Base (number of infants) 3438 3410

From Foster K, Lader D and Cheesbrough S (1997) Office for National

Statistics ^ Infant Feeding 1995. London: Stationery Office. Crown copyright

is reproduced with the permission of the Controller of Her Majesty’s

Stationery Office.

3292 INFANTS/Breast- and Bottle-feeding

Goedhart AC and Bindels JG (1994) The composition of

human milk as a model for the design of infant formulas:

recent findings and possible applications. Nutrition

Research Reviews 7: 1–23.

Golding J, Rogers I and Emmett P (1997) Breast feeding:

benefits and hazards. Early Human Development 49

(suppl.): S1–S204.

Henig MJ and Dewey KG (1996) Health advantages of

breast-feeding for infants: a critical review. Nutrition

Research Reviews 9: 89–110.

Henig MJ and Dewey KG (1997) Health effects of breast-

feeding for mothers: a critical review. Nutrition Re-

search Reviews 10: 35–56.

Holland B, Welch AA, Unwin ID et al. (1991) McCance and

Widdowson’s The Composition of Foods, 5th edn. Cam-

bridge: Royal Society of Chemistry, Ministry of Agricul-

ture, Fisheries and Food.

Macdonald S and Shaw V (1993) Breast- and bottle-

feeding. In: Macrae R, Robinson RK and Sadler MJ

(eds) Encyclopaedia of Food Science, Food Technology

and Nutrition, pp. 2507–2511. London: Academic

Press.

Statement of the Standing Committee on Nutrition of the

British Paediatric Association (1994) Is breast feeding

beneficial in the UK? Archives of Diseases in Childhood

71: 376–380.

Wharton B (1997) British Nutrition Foundation Briefing

Paper, Nutrition in Infancy. London: British Nutrition

Foundation.

White A, Freeth S and O’Brien M (1992) OPCS Report –

Infant Feeding 1990. London: HMSO.

Weaning

A MacDonald, The Children’s Hospital, Birmingham,

Introduction

0001 The term ‘weaning’ comes from the word ‘wenian,’

which means ‘to accustom.’ It is a gradual process

through which an infant moves from total depend-

ence on milk to eating normal family meals. The most

widely used definition is the process of introducing

semisolid food into the infant’s diet in addition to

milk. Definitions of weaning vary from country to

country and include ‘the process of expanding the

diet to include food and drinks other than breast or

infant formula,’‘cease to be suckled,’ or ‘complete

discontinuation of breast-feeding.’ As many of the

foods initially introduced are not truly solid, the

German word ‘beiokost’ is sometimes used to refer

to these foods as a group.

History of Weaning

0002In ancient Egyptian and Babylonian times, the

common age of weaning was 3 years. In the sixteenth

and seventeenth century, pap (mixtures of flour,

water, and sometimes milk) and panada (a broth of

bread, flour, meat or lentils, and sometimes milk)

were described as infant foods in the literature.

Weaning was quite a dangerous time when started

in early infancy, and Queen Anne is said to have lost

18 children from spoon-feeding and wet nursing. The

infant food industry started in 1867. By the latter part

of the nineteenth century, there was a more cautious

approach to solid-food introduction. It was widely

recommended that vegetables, particularly green,

were not given to infants before 2–3 years of age,

although cereals and custards were commonly intro-

duced by 4 months. The situation changed again in

the early part of the twentieth century with the trend

towards earlier weaning in developed countries. This

continued in the UK until the 1970s and 1980s, al-

though the latest Office of National Statistics (ONS)

report would suggest that more parents are delaying

the introduction of solids until at least 3 months

of age.

Why Wean?

0003There are four important reasons for weaning. These

are:

0004If an infant is still unweaned by 6 months, the

intake of energy is likely to be inadequate. Infants

double their birth weight in the first 4–5 months of

life (DOH, 1994), and breast or formula milk can

no longer meet energy needs. Late weaning is asso-

ciated with a failure to thrive in infants.

0005Breast milk provides little iron and vitamin D. In

the later stages of lactation, zinc and copper con-

centrations also begin to fall. However, the bio-

availability of nutrients in breast milk is good,

and no other foods are usually needed until the

age of 4 months, providing the mother is taking a

good mixed diet. In addition, for the first 4 months,

the full-term infant relies on iron stores to help

meet requirements. Sooner or later, these stores

will be depleted, and iron-deficiency anemia will

occur unless there is a supply from the weaning

diet. Formula milk contains higher quantities of

iron, vitamin D, zinc, and copper, but with a differ-

ent bioavailability than breast milk, but for other

reasons, it is still recommended that solids be

introduced by 6 months.

0006There are important developmental reasons for

introducing solid food. The neuromuscular coord-

ination needed to eat solid foods develops during

INFANTS/Weaning 3293

the early months of life. At 4 months, most infants

can put objects to their mouths, take soft foods

from a spoon, from a bolus and swallow (Table 1).

From about 5 months, teeth begin to erupt, and

infants are able to chew. Feeding behavior therefore

proceeds from sucking to biting and chewing.

Chewing improves the mouth and tongue coordin-

ation, which is important for speech development.

Introduction of different tastes and textures pro-

motes biting and chewing skills. However, if intro-

duction of solids is delayed beyond 6 months, the

weaning process becomes more difficult. Infants

are less receptive to new tastes, and it is more

difficult to teach older infants to chew. From 7

months of age, infants learn to shut their mouths,

turn their heads, and refuse to feed.

0007 The fourth reason is to provide a variety of tastes

and flavors. This will enable the infant to eventu-

ally accept and enjoy normal family meals.

When to Wean?

0008 The ideal time to introduce solids will vary between

infants and differ between cultures. In traditional

societies, it is still practice for infants to be almost

entirely breast-fed for the first year of life. In many

Western countries, particularly Europe and North

America, it is recommended that ‘the majority of

infants should not be given solids before the age of

four months but a mixed diet should be offered by the

age of six months’. Early weaning is discouraged for a

number of reasons:

0009 Poor muscular coordination. Before 3 months of

age, infants have poor head control, and back sup-

port is weak, so it is difficult to hold infants in a

position where they can be fed and can swallow

semisolid food.

0010The kidney is immature and may not be able to cope

with a higher renal solute load, and this could lead to

higher plasma concentrations of sodium and urea if

there is insufficient water available for their excretion.

0011The gastrointestinal tract is immature, intestinal

and pancreatic enzyme production is not fully de-

veloped, and the gut is more permeable to some of

the foreign proteins introduced with food, thus

increasing the risk of allergic reactions.

0012Early weaning in the developing countries has been

associated with a poorer growth velocity than in

infants who are exclusively breast-fed. This is

probably associated with the lower energy density

of the cereal-based gruel offered, resulting from the

addition of extra water to produce a food of suit-

able consistency. Also, iron bioavailability from

cereal-based gruel is low. Another major problem

is that contaminated weaning foods causes infec-

tion and diarrhea. This, in turn, increases nutri-

tional requirements but often reduces an infant’s

appetite and overall nutritional intake.

0013Solid feeding before 15 weeks is associated with in-

creased wheeze during the first seven years of life.

There is also evidence that early exposure to solids is

associated with an increased risk of eczema. In a

group of children studied until the age of 10 years, it

has been reported that infants given solids during the

first 4 months were 1.6 times more likely to develop

eczema than infants not given solids before 4 months.

0014There is evidence that early introduction of solids is

associated with increased body fat and weight in

childhood.

0015There is some suggestion that early introduction of

gluten in solids may contribute to a higher inci-

dence of coeliac disease. In Glasgow, for example,

records indicate that increased numbers of children

were admitted to hospital with celiac disease and

were diagnosed earlier during 1958–1965 and

1966–1973 than during 1950–1957. Cereals con-

taining gluten were also introduced earlier in Glas-

gow during 1958–1963, and 91% of infants were

given gluten by 3 months of age in 1965.

In Western countries, there is still a trend towards

early weaning. The ONS survey reported that 55%

of infants had been given solids by 3 months and 91%

by 4 months. Babies of Asian origin in the UK were

given solids slightly later than white babies, but 90%

still had solids by 4 months.

Nutritional Requirements of the Weaning

Infant

0016In the early months of infancy, the nutrient intake is

derived almost totally from human or infant formula,

tbl0001 Table 1 Developmental changes relevant to weaning

4months

Can maintain posture if supported in a chair

5months

Can take soft, pure

ed food from a spoon, form a bolus, and

swallow it

Can hold objects and put them to their mouths to suck

6months^8months

Teeth begin to erupt

Sits without support

Can chew

Can hand feed items like biscuits

Learns to shut mouth, turn head, and indicate feed refusal

9^12 months

Can sit easily

Attempts to use spoon

Indicates and understands ‘no’

Pincer grasp of small objects

3294 INFANTS/Weaning

but in later months, the diet becomes more diverse

with the introduction of solid foods. In ensuring that

the provision of all nutrients is met for infants, a

careful selection of solid foods given in the appropri-

ate amount is required.

Energy

0017 Energy should be provided in adequate quantities

throughout infancy to provide fuel for the basal meta-

bolic rate (BMR), growth, and physical activity. The

amount of energy required per kilogram of body

weight declines gradually, owing to a decreasing

growth rate and BMR, even though the energy re-

quirements for activity will increase as the infant

becomes older.

0018 The UK estimated average requirements (EAR) for

energy are given in Table 2. These are based on results

of studies using the doubly labelled water technique

of measurement that reflects the total energy expend-

iture in free living infants and children with additions

made for the energy value of new tissue deposited

during normal growth.

0019 Despite the introduction of solids, milk still needs

to provide a significant proportion of the total energy

intake throughout the first year of life. Fat contributes

50% of the energy in breast and infant formula milk

and is the main source of energy in infants less than

6 months of age. It still continues to be important in

childhood, and infants over 6 months of age will still

need 500–600 ml of milk daily. From studies estimat-

ing the nutrient intake of older infants, solids contrib-

uted 52, 57, and 64% of the total energy intake at

between 7 and 8 months, 9 and 10 months, and 11

and 12 months, respectively, whilst milk made up the

rest of the energy deficit.

0020 However, adequate energy from weaning foods

should be assured, and the energy density of weaning

foods is important. If it is high in carbohydrate and low

in fat, the food will be very bulky, and it may be difficult

for the infant to eat sufficient quantities to meet their

energy needs. Failure to thrive, which is a common

problem in developing countries, may result.

Protein

0021 Protein is a crucial determinant of linear growth;

it provides nitrogen and essential amino acids for

synthesis of body tissue. The DOH (1994) recom-

mends an adequate intake of protein with a proper

balance of essential amino acids during weaning

(Table 3). The protein/energy ratio is also important,

and it is recommended that infants between 6 and 9

months have an intake of not less than 1.74 g of pro-

tein per 100 kcal. In developed countries, there should

be few problems in achieving an adequate energy/

protein ratio, but in developing countries, if weaning

foods such as rice and maize are supplemented with oil

to improve energy density, this would significantly

reduce the energy/protein ratio below the minimum

safe ratio.

Vitamins and Minerals (Table 4)

0022Vitamin A This is required for growth, normal

development, and differentiation of tissues. The

1988 FAO/WHO Expert Group considered that a

daily intake of 350 mg retinol equivalents would

meet the needs of all healthy infants and allow the

building and maintaining of sufficient liver stores.

0023Vitamin D This has an important metabolic role in

the control of calcium homeostasis and deposition

of calcium in bones and teeth. There are two main

forms of vitamin D: cholecalciferol, formed by the

action of sunlight on 7-dehydrocholesterol, which

occurs naturally in the skin of man, and ergocalcif-

erol, a synthetic source of vitamin D. Weaning infants

are vulnerable to poor vitamin D status. Weaning

diets are generally low in vitamin D, and breast milk

contains little vitamin D. Infant formula is fortified

with vitamin D, and provided adequate amounts are

consumed, infants fed these products are unlikely to

become depleted. In the UK, it is recommended that

tbl0002 Table 2 Estimated average requirements for energy during

weaning (DOH, 1991)

Age (months) Energyrequirement (kcal kg

1

day

1

)

3 100

695

995

12 95

tbl0003Table 3 Reference nutrient intake for protein during weaning

(DOH, 1991)

Age (months) Protein (g

1

day

1

)

4–6 1.6

7–9 1.6

10–12 1.5

tbl0004Table 4 Reference nutrient intake for vitamins and minerals

during weaning (DOH, 1991)

Nutrient Age

0^3 months 4^6 months 7^12 months

Vitamin A (mg) 350 350 350

Vitamin D (mg) 9 9 7

Vitamin C (mg) 25 25 25

Calcium (mg) 525 525 525

Iron (mg) 1.7 4.3 7.8

Zinc (mg) 4.0 4.0 5.0

INFANTS/Weaning 3295

vitamin supplements including vitamin D be given to

breast-fed infants from the age of 6 months and

to formula-fed infants when the volume of milk

decreases below 500 ml daily.

0024 Iron This is an important nutrient during weaning,

which is necessary for the structure of the heme part

of hemoglobin, as well a component of myoglobin

and many enzymes. For breast-fed infants, after the

age of 6 months, the amount of iron from breast milk

is insufficient to meet increasing needs. Therefore,

adequate intakes of iron, from heme (meat) and non-

heme sources (cereals, pulses, and vegetables), should

be encouraged with foods rich in vitamin C to aid

absorption. Furthermore, the absorption of iron from

breast milk is greater if breast feeds are given separ-

ately from solid food as inhibitors in the food bind the

iron from breast milk in unabsorbable complexes.

Formula milks in the UK are fortified with iron, and

providing infants are taking over 500 ml daily, they

are at less risk of iron-deficiency anemia. However, it

is still important that iron-rich weaning foods be

encouraged.

0025 Zinc This is a component of several mammalian

enzymes and is active in many metabolic pathways.

Zinc deficiency may limit growth and may be a vul-

nerable nutrient during the weaning period. In the

UK, there is evidence that the average daily intake of

zinc is below the reference nutrient intake. Although

meat and meat products are the richest sources of

zinc, these foods provided only 10% of the dietary

zinc intake.

Which Foods Should be Given?

0026 Initial foods should be semisolid and have a smooth

consistency and bland taste, and suitable first foods

are cereal, such as baby rice or pure

ed home cooked

rice, mashed potato, custard, plain (unsweetened)

yogurt and pure

ed fruit, and vegetables. This should

then progress to pure

ed meat, pulses, and a wider

variety of cereals. In many parts of the world, the

first food to be introduced is traditionally a cereal.

In western European cultures, a commercially pre-

pared infant cereal containing added vitamins and

minerals is commonly the first food. In developing

countries, the local staple cereal is more likely to be

given, and this may include cereals such as corn,

barley, oatmeal, millet, sweet potato, cassava, rice,

plantain, yam, arrowroot, potato, or sago. These are

mixed to a porridge or paste with milk or water.

0027 Between the age of 6 and 12 months, the texture of

foods given should gradually progress from semisolid

to soft family foods. From the age of 6 months,

minced or mashed food with soft finger foods can be

encouraged. Meat should be coarsely pure

ed; whole-

meal cereals or instant oat cereal can be given in

addition to well-cooked egg. Suitable finger foods

include soft fruits, e.g., banana and melon, cheese

fingers, soft cooked carrot and fingers of toast, chap-

patti, and pitta bread.

0028From the age of 10 months, foods such as meat

should be minced or finely chopped. Cooked vege-

tables need only be chopped, and pasta dishes with

small shaped pasta can be given. Finger foods are

particularly important at every meal to encourage

the infant to participate in self-feeding.

Commercial Versus Home-made Family Weaning

Foods

0029Homemade family weaning foods The use of appro-

priately home-made foods is encouraged, and in the

UK, about 40% of infants are given some home-made

weaning foods. They have several advantages: (1)

they accustom an infant to the taste of adult-based

food; (2) they are cheap and easy to prepare; (3)

wastage is low; and (4) meat-based Halal weaning

foods can be prepared for Muslim infants. Unfortu-

nately, analysis of home-made weaning foods from

the UK has revealed that some meals contain low

amounts of energy, iron, and zinc but high amounts

of nonstarch polysaccharides, protein, and sodium.

Intakes of iron are also lower in infants receiving

mainly family foods. Typical home-made foods

given to a group of 6- to 8-month-old infants from a

deprived inner city area in the UK were mashed

potato, tinned spaghetti, and baked beans. However,

breast or infant formula milk or cereal can be added

to home-made weaning foods to the improve energy

and nutrient density.

0030Commercial baby foods In the developed world,

commercial weaning foods (tins, jars, and packet

foods) are popular, especially cereals, ready meals,

and desserts. They may be fortified with extra vita-

mins and minerals, and contain no added salt.

Even with commercial baby foods, there are some

cultural differences concerning manufactured foods

given to infants. The Italians prefer individual con-

stituents, i.e., a meat dish to which pasta can be

added, whereas the British prefer composite sweet

and savory dishes.

0031The Codex Alimentarius Commission (WHO/

FAO) has set compositional standards for baby

foods. In 1996, the European Commission issued a

directive on processed cereal-based foods and baby

foods for infants and young children (96/5/EC); it was

amended in 1999. The regulations prescribe manu-

facturing, compositional and labelling requirements

3296 INFANTS/Weaning

and prohibit the sale of any processed cereal-based

food or baby food, unless it complies with the regula-

tions. The UK government has also published an

expert report on additives in food specially prepared

for infants and young children, which recommended

that additives should only be used when there is a

strong justification on technological grounds.

0032 Although not essential, most mothers in developed

countries use commercially produced weaning foods

at some stage because they are so convenient. In the

early stages of weaning, dried products can be made

up in small quantities, so avoiding waste. However,

commercial weaning foods are relatively expensive,

there is a limited range of vegetarian foods, and there

is a tendency for some parents to keep infants on

strained varieties for prolonged periods of time,

which may contribute to the delayed acceptance of

more lumpy food.

Foods Avoided During Weaning

Salt

0033 In the West, it is widely recommended that salt should

not be added either to weaning foods during the

cooking process or to the food at the table, as the

developing kidney is unable to excrete large sodium

intakes. Excessive sodium intake in young infants is

associated with hypernatremia. In addition, there is

some concern that a high salt intake in infancy and

childhood may cause hypertension in later life; the

evidence for this is unconvincing.

Sugar

0034 It is recommended in North America and Europe that

sugar should be kept to a minimum and should not be

added to foods during preparation. The preference

for sweet foods and drinks has been demonstrated

even in preterm infants. To avoid encouraging the

taste for sweet foods and to reduce the risk of dental

caries, sugar should be avoided as much as possible.

Even so, in the UK, it is common to introduce sugar-

based foods early in the diet. In the MAFF survey

looking at infant feeding practices between 6 and 12

months, 62% had been given sweets and chocolate,

70% received biscuits, and 45% of mothers gave

milk-based dishes sweetened with sugar.

Gluten

0035 There are many disputes about the best time to-

introduce gluten into the diet. Delayed introduction

is associated with an increased age of onset, although

there are those who maintain that it decreases

the incidence. Challacombe et al. (1997) suggest

that later introduction of gluten, increased use of

gluten-free foods for weaning, and increased

incidence of breast-feeding are associated with a de-

creasing incidence of celiac disease and transient

gluten intolerance. However, in Sweden, a doubling

of the gluten content of commercial baby foods

was associated with an increased incidence of celiac

disease from 1.7 children per 100 live births during

1978–1982 to 3.5 per 1000 thereafter. This occurred

in spite of an increased prevalence and duration of

breast-feeding and the delay in the introduction of

dietary gluten from 4 to 6 months. Gluten-sensitive

individuals who are breast-fed and who are intro-

duced to gluten relatively late may not present clinic-

ally during weaning, although the disorder is still

thought to manifest at an older age, and the cumula-

tive prevalence is unaffected. Therefore, to prevent

celiac disease developing at least during the early

weaning period, when the infant is particularly vul-

nerable nutritionally, it is recommended by most

health professionals that cereals given to infants

under 6 months should be gluten-free.

Food Allergens

0036Infants are most vulnerable to the initiation of food

allergy in the first months of life, and the risk of

food allergy is greatly increased by family history of

atopic disease such as eczema and asthma. When

there is a strong family history of allergy, mothers

should be encouraged to breast-feed for 6 months or

longer. Weaning should be particularly discouraged

before 4 months, and foods traditionally regarded as

allergenic (e.g., cows’ milk, soya protein, gluten, eggs,

fish, and nuts) should not be introduced until 6

months of age at the earliest. In the UK, a working

group for the Committee on Toxicity of Chemicals in

Food, Consumer Products, and the Environment rec-

ommended that peanuts or peanut products should be

avoided until 3 years of age in all children with a

parent or sibling with an atopic disease.

Suitable Milks During Weaning

0037Breast milk This should be encouraged, but from

6 months of age, breast milk cannot supply the re-

quirements for several micronutrients, including iron,

copper, zinc, and vitamin D. Dietary sources should

be given either as part of the weaning diet or as

specific supplements, e.g., vitamin D supplements.

0038Infant formula Providing it is iron-fortified, it

should be continued until the age of 1 year. It is a

particularly good source of vitamin D, and infant

formula sold in the UK is also rich in iron. Providing

that a volume of 500 ml daily is taken, there should be

no need to give extra vitamin supplements.

INFANTS/Weaning 3297

0039 Follow-on formula This is intended for older infants

over the age of 6 months. It is based on modified

cows’ milk. It contains less protein, calcium, and

phosphorus than cows’ milk but more than standard

infant formula. Most follow-on formula contains

almost double the iron and 45% more vitamin C

than standard infant formula. It can provide a useful

drink for older infants if breast-feeding has been

stopped or the volume of standard infant formula is

less than 400 ml daily. However, follow-on formula

should not replace breast milk or standard infant

formula if the volume of either is adequate.

0040 Whole cow’smilk This is not suitable for infants

under 1 year as the main drink. It is low in iron,

vitamin C, and vitamin D. It may be used in small

quantities in the preparation of solid foods.

0041 Goat’s and sheep’s milks These are low in iron,

vitamin D, and folic acid and should not be given to

infants under 1 year of age. Although these milks may

be perceived as less allergenic or else providing special

nourishment, none of these claims have been sub-

stantiated.

Problems Associated with Weaning

Iron-deficiency Anemia

0042 Iron-deficiency anemia in later infancy and the

toddler years is common throughout the world, and

simple dietary iron deficiency is the most common

cause. In the UK, it is particularly frequent in ethnic

and socio-economically deprived toddlers, and 4–

28% of older infants have been reported to have

iron-deficiency anemia. It can cause psychomotor

delay, apathy, irritability, reduced attention span,

pallor, decreased resistance to infection, reduced

exercise capacity, and poor appetite. It is associated

with prolonged use of breast-feeding, early intro-

duction of whole cow’s milk and inadequate dietary

iron during weaning. There have been many initia-

tives to try and reduce the prevalence of iron-

deficiency anemia in the Western world. These

include screening, health education, iron fortification

of food and extension of the use of iron-rich infant

formula. Although large-scale dietary education

has failed to reduce iron-deficiency anemia in the

UK (Child et al., 1997), programs to provide supple-

mented food containing iron to target groups

have been shown to be successful in the USA. In

addition, in the UK, a project extending the use

of iron-fortified follow-on formula beyond 1 year

significantly reduced the prevalence of iron-

deficiency anemia.

Rickets

0043Prolonged deficiency of vitamin D can result in rick-

ets. The main symptoms include skeletal deformity,

delayed dentition, bone pain, muscle weakness,

hypocalcemia, misery, and failure to thrive or short

stature. Children under 3 years are particularly

vulnerable to a poor vitamin D status because of

demands resulting from the high rate at which cal-

cium is being laid down in the bone. Although it is

uncommon in Europe and North America, new cases

are still being reported particularly in northern

climates (Gessner et al., 1997) and immigrant chil-

dren (Brundvand and Nordshus, 1996). In the UK,

low-serum 25-hydroxycholecalciferol concentrations

have been noted in 20% of Bangladeshi, 34% of

Pakistani, and 25% of Indian 2-year-old children

living in England (Lawson and Thomas, 1999). Low

25-hydroxy vitamin D levels have been noted in

the winter in British children not taking vitamin D

supplements.

0044Rickets is commonly reported in some hot climates.

In a recent Nigerian study, overt rickets was found in

2.4% of households. Factors in hot climates such as

increasing urbanization and the tendency of mothers

and their young children to avoid exposure to sun-

light, either by remaining indoors or in the shade or

by covering the skin, must all contribute to a de-

creased endogenous synthesis of vitamin D, in com-

bination with a poor vitamin D or calcium intake. In

western countries, prolonged breast-feeding by

mothers of poor vitamin D status, early introduction

of whole cows’ milk, poor weaning sources of vitamin

D, little exposure to sunlight, and even the use of

sunscreen are contributing factors.

Vitamin A Deficiency

0045In the developing world, vitamin A deficiency is one

of the most common causes of blindness in children,

particularly in the Middle east, the Indian subcontin-

ent, and South-east Asia. It causes xerophalmia, ker-

atomalacia, and eventually blindness. This is due to

reduced infant stores of vitamin A due to maternal

deficiency, low vitamin A-containing breast milk, and

weaning diets low in preformed retinol from animal

food. Vitamin A deficiency is often accompanied by

protein-energy malnutrition. Vitamin A supplements,

even in the absence of clinical overt deficiency, reduce

child mortality.

Weaning Practices in Developing

Countries

0046The weaning infant is potentially at risk in developing

countries, and many nutritional problems arise with

3298 INFANTS/Weaning

the introduction of solids. The need to introduce

nonmilk food sources with only the availability of

rather crude preservation processes, poor hygiene,

sanitation, and inadequate water supplies introduces

the risks of gastrointestinal and parasitic infection

because of the heavy contamination of foodstuffs

with infecting organisms. In rural Bangladesh, a sig-

nificant association has been found between the fre-

quency of isolation of Escherichia coli in the weaning

foods and E. coli diarrhea in the infants consuming

them, and there can be little doubt that food plays an

important role in the epidemiology of diarrhea in

young children. The effects of infection lead to anor-

exia and pyrexia with increased metabolic require-

ments, and this can only serve to exacerbate any

effects of a poor nutritional intake. In addition,

many infants have been breast-fed for prolonged

periods of time without weaning solids, and when

they are introduced, it is probably a low-energy-

density, cereal-based gruel that may be given only

once or twice a day. The continued effects of deterior-

ating nutritional status and infection may lead to

protein-energy malnutrition.

See also: Anemia (Anaemia): Iron-deficiency Anemia;

Atherosclerosis; Carotenoids: Occurrence, Properties,

and Determination; Celiac (Coeliac) Disease;

Cholecalciferol: Properties and Determination; Food

Intolerance: Food Allergies; Infant Foods: Weaning

Foods; Iron: Properties and Determination; Metabolic

Rate; Protein: Requirements; Retinol: Properties and

Determination; Rickets and Osteomalacia; Zinc:

Properties and Determination; Deficiency