Chapter 3: Provide infant nutrition

The provision of appropriate nutrition during infancy is a critical foundation for lifelong health and development. Nutrition and Dietetics professionals in Kenya play a vital role in ensuring infants receive the right nutrients at the right time, which supports optimal growth, cognitive development, and immune function. Understanding the nutritional needs of infants requires comprehensive assessment skills to identify both individual requirements and potential risks. This chapter delves into the nutritional demands of infants, the importance of adequate nutrition, and methods to assess these needs effectively in clinical and community settings.

3.1 Nutritional needs for infants

An infant is a child under twelve months of age. Growth in the first year is rapid: a baby usually doubles its birth weight by about five months and triples it by twelve months, while the brain grows quickly. This topic sets out the nutrients an infant needs, why feeding in the first year matters so much, and how a dietitian checks that a particular infant is being fed well, using measurements, laboratory tests, a physical examination and the feeding history. Infants are cared for by the dietitian, the clinic nurse, the clinician and the mother together, so each method also states when to refer.

3.1.1 Introduction to nutrition needs for infants

Nutrition needs for infants are the quantities of energy, protein, fat, carbohydrate, vitamins, minerals and fluid that must be taken in for an infant to grow, stay healthy and develop normally. They are large for the infant's size, because new tissue is being built as well as maintained, and the stomach is small, so food must be rich and feeds frequent.

Breast milk meets the needs of a healthy term infant for the first six months, and it goes on contributing after that. From six months the infant's stores of some nutrients, especially iron, are running low and the infant is more active, so safe, nutrient-dense complementary foods are added to continued breastfeeding. The needs of the infant therefore change at about six months, and an assessment starts by asking the infant's age and how the infant is fed.

Why infant needs are high for body size

Rapid growth, a high rate of metabolism and a large brain in proportion to the body mean an infant needs more energy and protein for each kilogram of body weight than an adult. Fat supplies about half the energy in breast milk and is also needed to build the brain and nerves. The infant's kidneys and gut are still maturing, so very concentrated feeds or unsuitable foods are not handled well.

Needs from birth to six months

In this period a healthy infant needs breast milk and nothing else, or a suitable infant formula when breastfeeding is not possible. Water, herbal drinks, porridge and other foods are not given, because they displace milk and can carry germs. Breast milk supplies all the fluid an exclusively breastfed infant needs, including in hot weather, and a formula-fed infant takes fluid in correctly prepared feeds. Feeds are frequent, usually eight or more in 24 hours, and follow the infant's hunger signs.

Needs from six to twelve months

Breast milk still gives energy, fluid and protective factors, but it can no longer meet the infant's requirement for iron, zinc and some other nutrients. Complementary foods are started at six months in small amounts and increased in quantity, variety and thickness as the infant grows. They must be timely, adequate, safe and properly fed. Frequency of feeding rises with age, and boiled and cooled water is offered with meals.

How reference values are used

Reference intakes are planning figures calculated for healthy groups of infants. They serve the dietitian as a guide and never as a pass mark for one infant, and they are read alongside how the infant is growing, how healthy the infant is and how the infant is fed. The figures in this topic are the Dietary Reference Intakes of the Institute of Medicine (now the National Academy of Medicine) of the United States and Canada, which are widely used in training. At work, the national table is used where one exists.

3.1.2 Importance of nutrition in infants

What an infant is fed in the first twelve months affects survival, growth, learning and health in later life. The harm of poor feeding in this period is the hardest to undo, which is why infancy is a priority in clinic and community nutrition work.

Impact of nutrition on infant growth and development

• Physical growth: enough energy and protein allow normal gain in weight and length, which are the main signs of health in infancy.
• Brain development: iron, iodine, fatty acids such as DHA and folate support the growth of nerve cells and their connections.
• Immune competence: breast milk gives antibodies, and adequate vitamin A and zinc keep the gut and lungs strong against infection. Pneumonia and diarrhoea are major causes of illness and death in young children in Kenya, and undernourished infants fall ill more often and recover more slowly.
• Metabolic programming: early feeding affects how the body handles energy later, and both undernutrition and overfeeding in infancy are linked with a higher risk of diabetes and high blood pressure in adult life.
• Psychosocial development: a well-nourished infant is alert and responsive. Responsive feeding, where the mother notices and answers hunger and fullness signs, builds bonding and early learning.

Consequences of poor infant nutrition

• Stunting: a long-term shortfall in food and repeated infection give low length for age and slower mental development.
• Wasting: recent weight loss or failure to gain gives low weight for length and a raised risk of death.
• Micronutrient deficiencies: lack of iron, vitamin A, vitamin D, iodine and zinc leads to anaemia, eye damage, rickets and delayed development. They are described under Infant nutrition related complications.
• More illness: an undernourished infant has more infections and more admissions to hospital.
• Economic effect: treatment costs fall on the family and the health service, and children who were poorly fed in infancy may achieve less in learning and later at work.

3.1.3 Assessment of nutritional needs in infants

Assessing the nutritional needs of an infant means finding out whether the infant is feeding and growing well and, if not, why. The dietitian draws on four kinds of evidence: measurements of the body, laboratory results, signs found on examination and what the infant is fed. One method by itself can mislead: a normal weight can mask a poor diet, and a good recall can mask an infection that is holding back growth. The dietitian follows the facility's protocol, explains each step to the mother, records findings clearly and refers to the clinician when a finding lies outside dietetic care.

Socioeconomic and environmental factors

An infant's nutrition depends on the household. Questions cover whether the household has enough food, who cares for the infant during daytime hours, the mother's workload and schooling, whether clean water and a toilet are available, and what the family believes about feeding infants. A mother who returns to work early may need help planning how to keep breastfeeding, for instance by expressing and storing milk. Infants in crowded settlements with poor sanitation face repeated infections and so poorer growth. These findings shape the advice given and the referrals made to community health services.

3.1.3.1 Anthropometry

Anthropometry means measuring the infant's body, for example weight and length, to judge how well the infant is growing and nourished. It is done at each infant visit, because the tools are simple and the results show progress over time.

• Weight: read from an infant scale marked in 10 g steps, with the infant undressed and the scale zeroed before every weighing.
• Length: measured with the infant lying on a length board and two people working together: one keeps the head against the fixed headboard, while the other straightens the legs and slides the footboard up to the heels.
• Head circumference: measured with a tape that does not stretch, passed just above the eyebrows and over the most prominent part of the back of the head. It follows brain growth.
• Mid-upper arm circumference (MUAC): taken on the left arm, midway between the shoulder tip and the elbow, from six months of age. A MUAC below 11.5 cm indicates severe acute malnutrition and 11.5 cm to below 12.5 cm indicates moderate acute malnutrition. It is not used for infants under six months.

Each measurement is compared with the WHO Child Growth Standards, which give the median and cut-off lines called z-scores for each age and sex. A weight-for-age below minus 2 z-scores means underweight, which does not show whether the problem is recent or long standing. A length-for-age below minus 2 means stunting, which signals long-term undernutrition. A weight-for-length below minus 2 means wasting. A value below minus 3 is severe, and a weight-for-length above plus 2 suggests overweight.

One measurement tells less than the line it joins, so each visit is plotted on the growth chart and the direction of travel is read.

Worked example: an infant weighed 3.1 kg at birth and 5.8 kg at 14 weeks. The gain is 5.8 − 3.1 = 2.7 kg, which is 2,700 g. The gain per week is 2,700 ÷ 14 = 192.9 g, about 193 g a week. This is within the usual range for the first three months, roughly 150 to 200 g a week, so the dietitian praises the mother and plans the next weighing.

3.1.3.2 Biochemical assessments

Biochemical assessments are laboratory tests on blood, urine or stool that measure nutrients or their effects. They back up what other methods suggest and can detect a deficiency before any signs show. They are requested by the clinician or within the facility's protocol and are not done on every infant.

• Haemoglobin: measured on a finger or heel prick with a point-of-care meter or in the laboratory. WHO defines anaemia in a child as haemoglobin below 10.5 g/dL at 6 to 23 months and below 11.0 g/dL at 24 to 59 months.
• Serum ferritin: shows stored iron. A level below 12 µg/L in a child under five years indicates depleted stores. Infection raises ferritin, so a normal value in a sick child can mislead.
• Serum retinol: shows vitamin A status, and a level below 0.70 micromoles per litre indicates deficiency.
• Blood glucose: measured with a glucometer in a sick or severely malnourished infant, as a low level is dangerous.
• Stool examination: looks for parasites and blood in an infant with long-lasting diarrhoea or poor growth.
• Test for malaria: done when the infant has fever, because malaria causes anaemia and poor feeding.

Blood collection in infants uses a single-use lancet, clean hands and gloves, and the lancet goes straight into a sharps container. Used lancets are not cleaned or used again. The mother is told that only a few drops are needed, and the infant can be comforted by breastfeeding afterwards.

3.1.3.3 Clinical monitoring

Clinical monitoring means looking at the infant's body and behaviour for signs of poor nutrition and checking general health at the same time. It starts with watching the infant's alertness, activity and cry and continues from head to feet.

• Pallor: pale palms, tongue or inner eyelids suggest iron deficiency anaemia. The dietitian reviews the diet and refers for a haemoglobin test.
• Swelling of both feet: pressing with a thumb leaves a pit. This is nutritional oedema, a sign of severe acute malnutrition, and the infant is referred urgently.
• Wasting: thin limbs, loose skin folds at the buttocks and a prominent rib outline show severe wasting and need urgent referral.
• Hair and skin: thin, sparse, light-coloured hair and peeling, flaky skin can accompany severe protein shortage.
• Soft skull, widened wrists and late closing of the soft spot on the head: suggest rickets from vitamin D deficiency, and the infant is referred.
• White patches on the tongue and cheeks: may be oral thrush, which interferes with feeding.
• Dry, dull eyes or foamy white spots on the white of the eye: suggest vitamin A deficiency and need urgent referral.
• Sunken eyes, dry mouth and slow return of a pinched skin fold: suggest dehydration, treated as taught in the topic Nutrition intervention plan.

Milestones for the age are also checked, for example holding up the head, smiling, sitting with support and reaching for objects. Poor nutrition, illness or other causes can delay development, and any delay is reported to the clinician. Danger signs such as being unable to drink or breastfeed, vomiting everything, convulsions, or being very sleepy or unconscious are referred at once.

3.1.3.4 Dietary assessments

Dietary assessment establishes what the infant is really given and sets it against what the infant needs. The information comes from the mother or caregiver, so questions are open, specific and non-judgemental.

• Feeding history: when breastfeeding began, how often and how long the infant feeds, whether any other fluid or food is given, the age at which complementary foods started, and how formula is prepared if used.
• 24-hour recall: the mother describes everything the infant took in the last day and night, with portion sizes in household measures.
• Food frequency questions: how often in a week the infant eats iron-rich foods, vitamin A-rich foods, animal-source foods and sugary drinks.
• Feeding indicators for infants aged 6 to 23 months: WHO defines minimum dietary diversity as eating from at least five of eight food groups in the day, and minimum meal frequency for a breastfed infant as two feeds of solid or semi-solid food at 6 to 8 months and three at 9 to 23 months.

Worked example: the mother of a nine-month-old, breastfed six times in the day, reports millet porridge with groundnut paste in the morning, mashed pumpkin with kale at midday and mashed sweet potato with egg in the evening. The food groups are breast milk, grains and roots, legumes and nuts, vitamin A-rich vegetables and eggs, which is five, so minimum dietary diversity is met. Three feeds of food meet minimum meal frequency for a breastfed infant of this age. The dietitian suggests adding a small portion of fish or beans for iron.

The dietitian then compares intake with reference values. The table gives the Dietary Reference Intakes used in the sub-items that follow: adequate intakes for 0 to 6 months, where breast milk is the benchmark, and recommended or adequate intakes for 7 to 12 months.

3.1.3.4.1 Macronutrients

The macronutrients, carbohydrate, protein and fat, give energy and the building materials for growth. Breast milk provides them in suitable proportions: about half its energy comes from fat, and lactose is the main carbohydrate. Lactose supplies energy and supports healthy gut bacteria.

Energy need is estimated from weight. The Institute of Medicine equation is (89 × weight in kg − 100) + 175 kcal a day from 0 to 3 months, + 56 kcal from 4 to 6 months and + 22 kcal from 7 to 12 months.

Worked example: an infant of 2 months weighs 5 kg. 89 × 5 = 445, then 445 − 100 = 345, then 345 + 175 = 520 kcal a day, which is 520 ÷ 5 = 104 kcal for each kilogram. At 10 months an infant of 8 kg needs 89 × 8 = 712, then 712 − 100 = 612, then 612 + 22 = 634 kcal a day, which is 634 ÷ 8 = 79 kcal for each kilogram. As growth slows, the energy needed for each kilogram of body weight falls.

Protein is about 1.5 g per kg a day in the first six months and is met by breast milk. From six months, mashed beans, eggs, fish and milk products add protein. The Institute of Medicine adequate intake for total fat is 31 g a day to 6 months and 30 g a day from 7 to 12 months, and for carbohydrate 60 g and 95 g a day. At assessment, the dietitian checks that complementary foods include a source of protein and fat each day and that porridge is thick, not watery.

3.1.3.4.2 Iron

Iron is required to make haemoglobin and for the developing brain. The iron an infant is born with lasts about six months and breast milk holds little iron, so after that age the infant relies on iron-rich foods. Infants born early or small, and infants of anaemic mothers, have smaller stores. Waiting at least one minute before clamping the cord after birth, as WHO advises, helps to build stores.

Good sources are liver, red meat, fish, eggs, beans, lentils, green leafy vegetables, and infant cereals or flour that have iron added. The body takes up iron from animal foods more readily than iron from plant foods, and vitamin C in the same meal helps it take up iron from plants. Tea and coffee lower absorption, so they are not given to infants. Cow's milk is not given as the main drink before twelve months, because it contains little iron and can cause small blood losses from the gut.

At assessment, the dietitian finds out how often iron-rich foods are offered, checks for pallor and refers the infant for a haemoglobin test if anaemia is suspected. For infants aged 7 to 12 months the reference intake is 11 mg a day.

3.1.3.4.3 Calcium

Calcium forms the structure of bones and teeth and helps muscles and nerves to work. Breast milk or formula supplies calcium in the first six months. From six months, milk, yoghurt, fermented milk, small fish eaten with their bones such as omena, and green leafy vegetables such as kale add to it.

The body uses calcium well only when vitamin D is adequate, so the two are assessed together. The dietitian asks whether the infant takes any dairy foods or fish with bones and looks for signs of poor bone hardening, described under Clinical monitoring. The reference intake is 200 mg a day up to 6 months, rising to 260 mg a day from 7 to 12 months.

3.1.3.4.4 Vitamin D

Vitamin D enables the gut to take up calcium and phosphorus, and bones need it to become strong. The skin produces it in sunlight, and small amounts come from oily fish and egg yolk. Breast milk contains little, so an infant's vitamin D depends mainly on sunlight and on the mother's own level.

A shortage leads to rickets. It is more likely in infants kept indoors, heavily wrapped, or living in areas with little sunlight, including crowded urban homes. The dietitian asks about outdoor time and clothing and refers an infant with signs of rickets to the clinician, who sets any supplement dose. The reference intake is 10 µg (400 IU) a day.

3.1.3.4.5 Zinc

Zinc is needed for growth, immune function and wound healing, and it shortens diarrhoea when given with oral rehydration solution as the clinician directs. In the early months zinc comes from breast milk, but from about six months it has to come from foods such as meat, liver, eggs, fish, groundnut paste and pulses.

Phytates in maize and legumes reduce zinc absorption, so a diet of plain porridge puts the infant at risk. Low zinc slows growth and prolongs diarrhoea. At assessment, the dietitian enquires about animal-source foods and any bouts of diarrhoea. The reference intake is 2 mg a day up to 6 months, rising to 3 mg a day from 7 to 12 months.

3.1.3.4.6 Vitamin A

Vitamin A supports vision, healthy skin, the lining of the gut and lungs, and the immune system. In the early months it is supplied by the breast milk of a well-nourished mother. From about six months the sources include liver, eggs, orange-fleshed sweet potato, pumpkin, mango, pawpaw, carrots, dark green leafy vegetables and fortified cooking oil.

Too little vitamin A leads to night blindness, dry eyes and a higher risk of severe infection. At assessment, the dietitian asks about vitamin A-rich foods, checks the child health card for the vitamin A supplements given at the clinic from six months as the national schedule directs, and looks for dry or foamy spots on the eyes. The reference intake is 400 µg RAE a day up to 6 months, rising to 500 µg RAE a day from 7 to 12 months.

3.1.3.4.7 Vitamin C

Vitamin C helps wounds to heal, keeps gums and blood vessels healthy and raises the uptake of iron from plant foods. Breast milk provides enough for the first six months. Once complementary feeding starts, it is supplied by fresh fruits and vegetables such as guava, orange, mango, pawpaw, tomato and green leafy vegetables.

Vitamin C is lost by long cooking and storage, so vegetables are cooked briefly and soft fruit is mashed fresh. A deficiency is uncommon in infants who eat fruit and vegetables, and its signs are bleeding gums and easy bruising. At assessment, the dietitian asks whether a fruit or vegetable is served with iron-rich meals. The reference intake is 40 mg a day up to 6 months, rising to 50 mg a day from 7 to 12 months.

3.1.3.4.8 Essential Fatty Acids (Docosahexaenoic acid (DHA) and Arachidonic acid (ARA))

Essential fatty acids are fats the body cannot make in enough quantity, so they must come from food. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) become part of the brain and the eye's retina, and the infant needs a lot of them during the first year. Breast milk contains both, and its DHA content depends on the mother's intake of fish.

Many infant formulas have DHA and ARA added, and the label states it. After six months, small fish such as omena and eggs add DHA and ARA, while cooking oil stirred into porridge supplies the parent fatty acids from which the body makes some of each. The Institute of Medicine table has no reference intake for DHA and ARA as such. At assessment, the dietitian asks whether the infant eats fish and eggs and whether the mother eats fish during breastfeeding. A very low-fat or watery diet puts brain growth at risk.

3.1.3.4.9 Fibre

Fibre is the portion of plant foods that the body cannot digest. It keeps stools soft and helps the bowel to work well. Infants need little, and their small stomachs fill quickly on bulky foods that give little energy.

Mashed fruit, vegetables, pulses and cereals supply fibre naturally, and the Institute of Medicine sets no separate target for infants. The aim is to steer clear of very bulky or coarse foods that fill the infant up without giving enough energy and nutrients. A thick, mashed, energy-rich porridge is better than a thin gruel with husk. At assessment, the dietitian asks about stool pattern and constipation and about the texture of foods, and notes whether the infant is filling up on low-energy foods.

3.1.3.4.10 Water

Water makes up most of the infant's body and is needed to control temperature and remove waste. Breast milk is about 87% water, so an exclusively breastfed infant needs no extra water in the first six months, even in hot weather. Extra water displaces milk and may bring germs.

When complementary foods start at six months, boiled and cooled water is given in small sips at mealtimes from a clean cup. The total water taken in from milk, food and drinks is about 0.7 litre a day from 0 to 6 months and 0.8 litre a day from 7 to 12 months. Diarrhoea, vomiting, fever and hot weather raise the risk of dehydration. At assessment, the dietitian asks about wet nappies, water offered and the safety of the water source.

Chapter Summary

This chapter explores the nutritional needs of infants, emphasizing the critical role nutrition plays in their growth and development. It covers various methods for assessing infant nutrition including anthropometry, biochemical tests, clinical monitoring, and dietary assessments to ensure accurate evaluation of nutritional status. The chapter then addresses common infant nutrition-related complications, highlighting the importance of early identification and management. Developing a nutrition intervention plan involves several steps and includes diverse approaches such as breastfeeding promotion, formula feeding guidelines, complementary feeding introduction, supplementation, and management of dehydration, allergies, and food intolerances. Education and counseling for mothers, along with deworming and diet planning, are also integral components of effective intervention. The process of carrying out nutrition interventions is explained with focus on implementation steps, necessary tools, and resources. Finally, monitoring and evaluating these interventions are discussed in detail, including growth and development tracking through various assessment methods, indicators of success, and potential challenges faced during this critical phase of infant nutrition care.