Chapter 3: Provide infant nutrition

Maternal, infant, and young child nutrition is a critical area for Nutrition and Dietetics professionals in Kenya, given the high burden of undernutrition and micronutrient deficiencies in early childhood. Optimal infant nutrition lays the foundation for healthy growth, cognitive development, and long-term wellbeing. This chapter focuses on understanding the specific nutritional needs of infants and how to assess these needs accurately to guide appropriate interventions within Kenyan healthcare settings such as maternal and child health clinics, county hospitals, and community nutrition programs.

3.1 Nutritional needs for infants

An infant is a child from birth to the first birthday. Infancy asks a great deal of food in proportion to body size: a baby roughly doubles its birth weight in the first five or six months and about triples it by twelve months, while the brain grows rapidly. This topic explains what an infant needs, why those needs matter for survival and development, and how a dietitian assesses whether a particular infant is meeting them, using measurements, tests, examination and the feeding history. Care of infants is shared between the dietitian, the clinic nurse, the clinician and the mother, so each method below also states when to refer.

3.1.1 Introduction to nutrition needs for infants

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

Breast milk meets the needs of a healthy term infant for the first six months, and the mother's milk keeps contributing after that. From six months, the infant's stores of some nutrients, especially iron, are used up and the infant is also more active, so safe and 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 it is being fed.

Many Kenyan families are well placed to meet these needs with home foods, but some face limited variety, repeated infections, early stopping of breastfeeding or foods of low nutrient density. A dietitian who understands the needs can see these gaps early and guide the mother.

Why infant needs are high for body size

Rapid growth, a high metabolic rate and a large head and brain relative to the body mean that an infant needs more energy and protein per kilogram than an adult. Fat is the main energy source in breast milk, supplying about half of its energy, and it is also needed for brain and nerve development. The infant's kidneys and gut are still maturing, so concentrated or unsuitable feeds are not well handled.

Needs from birth to six months

During this period the infant needs no food other than breast milk, or an appropriate infant formula when breastfeeding is not possible. Water, herbal drinks, porridge and other foods are not added. The infant's fluid needs are met by the milk itself, even in hot weather.

Needs from six to twelve months

Breast milk continues to supply energy, fluid and protective factors, but it no longer covers the infant's needs for iron, zinc and some other nutrients. Complementary foods are added in small amounts at first and in larger amounts and more variety as the infant grows. Water is offered with meals once complementary foods begin.

How reference values are used

Reference intakes are planning figures worked out for healthy groups of infants. A dietitian uses them as a guide, not as a pass mark for one infant, and reads them with the infant's growth, health and feeding pattern. The values quoted in this topic are the Dietary Reference Intakes of the Institute of Medicine of the United States and Canada, which are widely used in training. Where a national table exists, the national table is used at work.

3.1.2 Importance of nutrition in infants

Feeding in the first year shapes survival, growth, learning and later health. The effects are hardest to reverse when they occur in this period, which is why infancy is a priority in community and clinic nutrition work.

Survival and immunity

Adequate nutrition supports the infant's defences against infection. Pneumonia and diarrhoeal disease are important causes of illness and death in young children in Kenya, and undernourished infants fall ill more often and recover more slowly. Exclusive breastfeeding for the first six months gives the infant antibodies and other protective factors and lowers the risk of illness, particularly diarrhoea.

Growth and development

Good nutrition allows normal growth in weight, length and head size. Chronic undernutrition in infancy can lead to stunting, which is low length for age, and is linked with weaker learning ability and school performance later. Recovery is easier when the problem is found early, so regular measurement matters.

Prevention of chronic diseases

Early nutrition affects how the body handles energy later. Both undernutrition and overfeeding in infancy are linked with a higher risk of conditions such as diabetes and high blood pressure in adult life.

Psychosocial development

The brain depends on adequate energy, iron, iodine and fatty acids to build its connections. An infant who is deficient in iron or iodine may be slow in motor skills, language and attention. Responsive feeding, where the mother notices and answers the infant's hunger and fullness signs, also builds bonding and early learning.

Economic and social impact

Infants who are well nourished are more likely to grow into healthy and productive adults. Poor infant nutrition raises the cost of treating illness for families and for health services, and it limits what a child can later achieve.

3.1.3 Assessment of nutritional needs in infants

Assessing the nutritional needs of an infant means finding out whether the infant is growing and feeding well and, if not, why. A dietitian combines four sets of evidence: body measurements, laboratory tests, clinical signs and dietary information. No single method is enough on its own: a normal weight can hide a poor diet, and a good recall can hide an infection that is stopping growth.

The dietitian works within the facility's protocol, explains each step to the mother, records findings clearly and refers to the clinician when a finding is outside the dietitian's scope.

3.1.3.1 Anthropometry

Anthropometry is the measurement of the body to judge growth and nutritional status. It is the first assessment done at each infant visit because the tools are simple and the results show progress over time.

The usual measurements are:

• Weight: taken on an infant scale that reads to the nearest 10 g, with the infant undressed and the scale set to zero before each weighing.
• Length: taken lying down on a length board by two people, one holding the head against the fixed headboard and the other straightening the legs and bringing the footboard to the heels.
• Head circumference: taken with a non-stretching tape placed just above the eyebrows and around the widest part at the back of the head.
• Mid-upper arm circumference: taken from six months of age on the left arm, midway between the shoulder tip and the elbow. It is not used to classify infants younger than six months.

Each measurement is compared with the World Health Organization Child Growth Standards. The standards give median values and cut-off lines called z-scores for each age and sex. Weight-for-age below minus 2 z-scores means underweight, length-for-age below minus 2 means stunting, and weight-for-length below minus 2 means wasting. A value below minus 3 is severe. A weight-for-length above plus 2 suggests overweight.

A single point tells less than the line it joins. A dietitian plots each visit on the child's growth chart and looks at the direction of travel.

Worked example: an infant weighed 4.6 kg at 8 weeks and 5.5 kg at 12 weeks, which is an interval of 4 weeks or 28 days. The gain is 5.5 − 4.6 = 0.9 kg = 900 g. The gain per day is 900 ÷ 28 = 32.1 g, so about 32 g a day. This is in the range expected in the third month, so the dietitian praises the mother, confirms exclusive breastfeeding and arranges 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 in the body. They confirm what the other methods suggest and can find a deficiency before signs appear. They are requested by the clinician or by the dietitian within the facility's protocol, and they are not done as a routine on every infant.

Useful tests include:

• Haemoglobin: measured from a finger or heel prick with a point-of-care haemoglobinometer or in the laboratory. The World Health Organization (2024) defines anaemia as a 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 the level of stored iron, and is read together with an infection marker because infection raises ferritin.
• Serum retinol: shows vitamin A status, with a level below 0.70 micromoles per litre indicating deficiency.
• Blood glucose: checked with a glucometer in a sick or severely malnourished infant, because low blood sugar is dangerous.
• Stool examination: looks for parasites and blood in an infant with chronic diarrhoea or poor growth.
• Blood film for malaria: done when the infant has fever, because malaria causes anaemia and poor feeding.

Blood collection in infants uses a single-use lancet on the heel or finger, correct hand hygiene and gloves, and the lancet goes straight into a sharps container. A lancet is never cleaned or reused. The dietitian explains to the mother that a few drops are needed and comforts the infant by breastfeeding afterwards where appropriate.

3.1.3.3 Clinical monitoring

Clinical monitoring is the examination of the infant's body and behaviour for signs of poor nutrition, together with a check of general health. It begins with watching the infant's alertness, activity and cry and continues from head to feet.

The dietitian also checks the infant's development against milestones for the age, such as holding up the head, smiling, sitting with support and reaching for objects. Delay can come from poor nutrition, illness or other causes and is referred to the clinician. Danger signs such as inability to feed, repeated vomiting, convulsions or unusual sleepiness are referred at once.

3.1.3.4 Dietary assessments

Dietary assessment finds out what the infant actually receives and compares it with what the infant needs. For an infant the information comes from the mother or caregiver, so the way questions are asked matters: they are open, non-judgemental and specific.

The main methods are:

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

The dietitian then compares intake with reference values for the age. The table gives widely used reference intakes for the nutrients in the sub-items that follow. Values are the Institute of Medicine Dietary Reference Intakes: adequate intakes for 0 to 6 months, where breast milk is the benchmark, and recommended intakes for 7 to 12 months where one has been set.

3.1.3.4.1 Macronutrients

Macronutrients are carbohydrate, protein and fat, which supply energy and the materials for growth. Breast milk supplies them in suitable proportions and amounts: about half its energy comes from fat, and lactose is the main carbohydrate.

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

Worked example: an infant of 3 months weighs 6 kg. The energy need is 89 × 6 = 534, then 534 − 100 = 434, then 434 + 175 = 609 kcal a day. Per kilogram this is 609 ÷ 6 = 101.5, so about 100 kcal per kg a day. At 9 months an infant of 9 kg needs 89 × 9 = 801, then 801 − 100 = 701, then 701 + 22 = 723 kcal a day, which is 723 ÷ 9 = 80 kcal per kg. The need per kilogram falls as growth slows.

Protein need in the first six months is about 1.5 g per kg a day, and it is met by breast milk. After six months complementary foods such as mashed beans, eggs, fish and milk products add protein. In assessment, the dietitian checks that complementary foods supply a source of protein and fat each day and that porridge is not watery.

3.1.3.4.2 Iron

Iron is needed for haemoglobin and for brain development. A healthy term infant is born with iron stores that are used up by about six months, and breast milk contains little iron, so from that age the infant depends on iron-rich foods. Infants born early or small, and infants whose mothers were anaemic, have smaller stores.

Sources include liver, red meat, fish, eggs, beans, lentils, green leafy vegetables and iron-fortified infant cereals or fortified flour. Iron from animal foods is absorbed better than iron from plant foods, and vitamin C taken with a meal improves absorption of the iron from plants. Tea and coffee reduce absorption and are not given to infants.

At assessment, the dietitian asks how often iron-rich foods are given, looks for pallor and refers for a haemoglobin test where anaemia is suspected. The reference intake is 11 mg a day from 7 to 12 months.

3.1.3.4.3 Calcium

Calcium builds bone and teeth and supports muscle and nerve function. The infant gets calcium from breast milk or formula in the first six months, and from milk, yoghurt, fermented milk, small fish eaten with their bones, such as omena, and green leafy vegetables once complementary foods begin.

Calcium is used by the body only when vitamin D is adequate, so the two are assessed together. The dietitian asks whether the infant takes any dairy or fish with bones, and notes signs of poor bone mineralisation such as delayed closure of the soft spot on the head or widened wrists. The reference intake is 200 mg a day to 6 months and 260 mg a day from 7 to 12 months.

3.1.3.4.4 Vitamin D

Vitamin D lets the gut absorb calcium and phosphorus, and is needed for strong bones. The skin makes it when exposed to sunlight, and small amounts come from oily fish and egg yolk. Breast milk contains little vitamin D, so the amount an infant gets depends mainly on sunlight and on the mother's own status.

Vitamin D deficiency in infants can lead to rickets, and it occurs when infants are kept indoors, heavily clothed or in areas with little sun exposure, including in urban households. The dietitian asks about outdoor time and clothing, and about the mother's vitamin D status where known, and refers an infant with signs of rickets to the clinician. Where a supplement is needed, the clinician sets the dose. The reference intake is 10 µg a day.

3.1.3.4.5 Zinc

Zinc is needed for growth, immune function and wound healing, and it helps the infant fight diarrhoea. Breast milk supplies zinc in the early months, but from about six months the infant needs zinc from foods such as meat, liver, eggs, fish, groundnut paste and pulses.

Plant staples such as maize and legumes contain phytates which reduce zinc absorption, so a diet based on plain porridge is at risk. Zinc deficiency slows growth and prolongs diarrhoea. At assessment, the dietitian asks about animal-source foods and about episodes of diarrhoea. The reference intake is 3 mg a day at 7 to 12 months.

3.1.3.4.6 Vitamin A

Vitamin A is needed for vision, healthy skin and the lining of the gut and lungs, and for immunity. Breast milk of a well-nourished mother supplies it in the early months. Later sources are liver, eggs, orange-fleshed sweet potato, pumpkin, mango, pawpaw, carrots, dark green leafy vegetables, and fortified cooking oil.

Deficiency can cause night blindness, dry eyes and a greater risk of severe infection. At assessment, the dietitian asks about vitamin A-rich foods, checks the child health card for the vitamin A doses given at the clinic from six months of age, and looks for dryness or white spots on the eyes. The reference intake is 400 µg RAE a day to 6 months and 500 µg RAE a day for 7 to 12 months.

3.1.3.4.7 Vitamin C

Vitamin C is needed for healing, healthy gums and blood vessels, and it increases the absorption of iron from plant foods. Breast milk contains enough for the first six months. Later it comes from fresh fruits and vegetables such as guava, orange, mango, pawpaw, tomato and green leafy vegetables.

Vitamin C is easily lost by long cooking, so vegetables are cooked briefly and fruit is mashed fresh when it is safe to do so. Deficiency is uncommon in infants who take fruits and vegetables, and its signs include bleeding gums and bruising. At assessment, the dietitian asks whether fruit or vegetables are given with iron-rich meals. The reference intake is 40 mg a day to 6 months and 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 and must take in. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are built into the brain and the retina, and the infant's need is high in the first year. Breast milk contains both, and the amount of DHA depends on the mother's own intake of fish.

Many infant formulas contain added DHA and ARA, and the label states it. After six months good sources of DHA and ARA are small fish such as omena and eggs, while cooking oils added to porridge supply the parent essential fatty acids, linoleic acid and alpha-linolenic acid. The Institute of Medicine table gives no reference intake for DHA and ARA themselves. At assessment, the dietitian asks about fish and egg in the diet, and whether the mother eats fish while breastfeeding. A fat-free or very watery diet is a risk to the infant's brain growth.

3.1.3.4.9 Fibre

Fibre is the part of plant foods that is not digested. It softens stool and supports bowel health. Infants do not need much, and their small stomachs are quickly filled by bulky foods that supply little energy.

Fibre comes naturally from mashed fruit, vegetables, pulses and cereals, and no separate target is set for infants. The aim is to avoid very bulky, watery or coarse foods that fill the infant without supplying enough energy and nutrients. A thick, mashed, energy-rich porridge is better than a watery gruel with husk. At assessment, the dietitian asks about stool pattern, constipation, and the texture of foods, and observes whether the infant is filling up on low-energy foods.

3.1.3.4.10 Water

Water is the main part of the infant's body and is needed for temperature control and the removal of wastes. Breast milk is about 87 per cent water, and an exclusively breastfed infant needs no extra water in the first six months even in hot weather. Extra water displaces milk and may introduce germs.

From six months, when complementary foods begin, boiled and cooled water is offered in small sips with meals, using a clean cup. Total water intake from milk, food and drinks is about 0.7 L a day at 0 to 6 months and 0.8 L a day at 7 to 12 months. The risk of dehydration is higher with diarrhoea, vomiting, fever and hot weather. At assessment, the dietitian asks about wet nappies, offers of water and the safety of the water source.

Socioeconomic and environmental factors

An infant's nutrition also depends on the household. The dietitian asks about household food security, who looks after the infant during the day, the mother's workload and education, access to clean water and a toilet, and the family's beliefs about infant feeding. A mother who returns to work early may need help planning how to continue breastfeeding. Infants in crowded settlements with poor sanitation face a higher risk of repeated infection and so of poor growth. These findings shape the advice and the referrals to community health services.

Chapter Summary

This chapter explored the nutritional needs of infants, emphasizing the critical role of proper nutrition in early development and the various methods used to assess these needs, including anthropometry, biochemical tests, clinical monitoring, and dietary evaluations. It examined common infant nutrition-related complications such as malnutrition, iron and vitamin D deficiencies, feeding difficulties, infections, and allergies, highlighting their impact on infant health. The chapter then detailed the process of developing nutrition intervention plans, covering strategies like breastfeeding promotion, formula feeding guidelines, complementary feeding, supplementation, and management of dehydration and allergies. The implementation of these interventions was discussed, with attention to the necessary steps and resources required to ensure effective delivery. Monitoring and evaluation were presented as essential components for tracking progress, using tools such as growth measurements, biochemical assessments, clinical checks, and direct observation. Finally, the chapter addressed the indicators of successful nutrition interventions and the challenges encountered in maintaining consistent monitoring and evaluation practices.