17 Nutrition in the Lifecycle – Infancy


  • Nutrient Needs of an Infant
  • Breastfeeding
  • Bottled Formulas
  • When to Introduce Solid Foods
  • Food Allergies
  • Dental Carries

One of the most important parenting jobs is ensuring that children receive an adequate amount of nutrients to provide a strong foundation for the rest of their lives. Diet and nutrition significantly impact a child’s development from infancy into the adolescent years. A healthy diet affects growth and immunity, intellectual capabilities, and emotional well-being. This chapter will discuss the importance of breastfeeding, bottle formulas, and solid foods.


The choice to breastfeed is one that all new mothers face. Support from family members, friends, employers, and others can significantly help with both the decision-making process during pregnancy and the practice of breastfeeding after the baby’s birth. In the United States, about 75 percent of babies start out being breastfed. Yet by the age of six months, when solid foods should begin to be introduced into a child’s diet along with breast milk, only 15 percent of infants in the United States were still breastfed exclusively, according to the Centers for Disease Control and Prevention (CDC).

Education about breastfeeding typically begins with healthcare providers. During prenatal care and soon after a woman has given birth, doctors, nurses, and other clinicians can explain the benefits of breastfeeding and describe the proper technique. Nearly all births in the United States and Canada occur in hospital settings. Hospital practices in labor, delivery, postpartum care, and discharge planning can inform and support women who breastfeed. Once a new mother has left the hospital for home, she needs access to a trained individual who can provide consistent information. International Board Certified Lactation Consultants (IBCLCs) are healthcare professionals (often registered nurse or registered dietitian) certified in breastfeeding management that works with new mothers to solve problems and educate families about the benefits of this practice. Research shows that breastfeeding rates are higher among women who had infants in hospitals that make IBCLCs available to new mothers, rather than those who gave birth in institutions without these professionals on staff.

Besides, spouses, partners, and other family members can play critical roles in helping a pregnant woman decide to breastfeed and assist with feeding after the baby is born. Employment can also factor into a woman’s decision to breastfeed or her ability to maintain the practice. Employed mothers have been less likely to initiate breastfeeding. They tend to breastfeed for a shorter time than new mothers who are not employed or have lengthy maternity leaves. In 2010 in the United States, the Affordable Care Act (ACA) passage called for employers to provide accommodations within the workplace for new mothers to pump breast milk. This law requires a private and clean space within the workplace, other than a restroom, along with adequate break time for a woman to express milk.

Members of a community can also promote and support breastfeeding. New mothers can join peer counseling groups or turn to other women within their community who have previous breastfeeding experience. Besides, community-based programs can provide education and support. The US Department of Agriculture’s Women, Infants, and Children program provides information on breastfeeding for low-income families. Launched in 2004, the Loving Support program combines peer counseling with breastfeeding promotion efforts to increase duration rates across the United States. La Leche League is an international program that provides mother-to-mother support, encouragement, and breastfeeding education worldwide.

La Leche League of Arizona

Although breastfeeding should be recommended and encouraged for almost all new mothers, it is essential to remember that breastfeeding is a personal choice. Women should not be made to feel guilty if they cannot or choose not, to breastfeed their infants. A woman cannot breastfeed or is not in the baby’s best interest in rare cases. Parents’ Nutritional choices, such as breastfeed or bottle-feeding, affect early childhood development and a child’s health and wellness later in life. Therefore, it is imperative to promote and support the best practices for infants’ and mothers’ well-being.

Components of Breastmilk

Human breast milk provides adequate nutrition for infants, but it also protects newborns from disease. Also, breast milk is rich in cholesterol, which is needed for brain development. It is helpful to know the different types and components of breastmilk, along with the nutrients they provide to enable an infant to survive and thrive. Colostrum is produced immediately after birth, before milk production, and lasts for several days after the baby’s arrival. Colostrum is thicker than breast milk and is yellowish or creamy in color. This protein-rich liquid fulfills an infant’s nutrient needs during those early days. Although low in volume, colostrum is packed with concentrated nutrition for newborns. This special milk is high in fat-soluble vitamins, minerals, and immunoglobulins (antibodies) that pass from the mother to the baby. Immunoglobulins provide passive immunity for the newborn and protect the baby from bacterial and viral diseases.

Two to four days after birth, colostrum is replaced by transitional milk. Transitional milk is a creamy liquid that lasts for approximately two weeks and includes high fat, lactose, and water-soluble vitamins. It also contains more calories than colostrum. After a new mother begins to produce transitional milk, she typically notices a change in the volume and type of liquid secreted and increases her breasts’ weight and size.

Mature milk is the final fluid that a new mother produces. In most women, it begins to secrete at the end of the second week postpartum. Two types of mature milk appear during feeding. Foremilk occurs at the beginning and includes water, vitamins, and protein. Hind-milk occurs after the initial milk release and contains higher fat levels necessary for weight gain. These two types of milk ensure that a baby receives adequate nutrients to grow and develop properly.

About 90 percent of mature milk is water, which helps an infant remain hydrated. The other 10 percent contains carbohydrates, proteins, and fats, which support energy and growth. Like cow’s milk, the main carbohydrate of mature breast milk is lactose. Breast milk contains vital fatty acids, such as docosahexaenoic acid (DHA) and arachidonic acid (ARA). In terms of protein, breast milk contains more whey than casein (the reverse of cow’s milk). Whey is much easier for infants to digest than casein. A complete protein, which means all essential amino acids, is also present in breast milk. Total protein includes lactoferrin, an iron-gathering compound that helps absorb iron into an infant’s bloodstream.

Also, breast milk provides adequate vitamins and minerals. Although absolute amounts of some micronutrients are low, infants are more efficiently absorbed. Other essential components include digestive enzymes that help a baby digest breast milk. Human milk also provides the hormones and growth factors that help a newborn develop.

The Mother’s Diet

A mother’s diet can significantly impact milk production and quality. New mothers need to adjust their caloric and fluid intake to make breastfeeding possible. As is the case during pregnancy, the RDA of nearly all vitamins and minerals increases breastfeeding their babies. The RDA is 330 additional calories during the first six months of lactation and 400 extra calories during the second six months. The energy needed to support breastfeeding came from increased intake and stored fat. For example, during the first six months after her baby is born, the daily caloric cost for a lactating mother is 500 calories, with 330 calories derived from increased intake and 170 calories derived from maternal fat stores. This helps explain why breastfeeding may promote weight loss in new mothers. According to the IOM, lactating women should also drink 3.1 liters of liquids per day (about 13 cups) to maintain milk production.

During pregnancy, lactating mothers should avoid illegal substances and cigarettes. Some legal drugs and herbal products can be harmful, helping to discuss them with a healthcare provider. Some mothers may need to avoid certain things, such as spicy foods, that can produce gas in sensitive infants. Lactating women can drink alcohol, though they must avoid breastfeeding until the alcohol has completely cleared from their milk. Typically, this takes two to three hours for 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor, depending on a woman’s body weight. Precautions are necessary because alcohol exposure can disrupt an infant’s sleep schedule.

Benefits of Breastfeeding

Breastfeeding has several benefits, both for the mother and for the child. Breast milk contains immunoglobulins, enzymes, immune factors, and white blood cells. As a result, breastfeeding supports the baby’s immune system and lowers diarrhea incidence, along with respiratory diseases, gastrointestinal problems, and ear infections. Breastfed babies also are less likely to develop asthma and allergies, and breastfeeding lowers the risk of sudden infant death syndrome. Also, human milk encourages the growth of healthy bacteria in an infant’s intestinal tract. These benefits remain in place after an infant has been weaned from breast milk. Some studies suggest other possible long-term effects. For example, breast milk may improve an infant’s intelligence and protect against Type 1 diabetes and obesity, although research is ongoing in these areas.

Breastfeeding has many other essential benefits. It is easier for babies to digest breast milk than bottle formula, which contains proteins made from cow’s milk that require an adjustment period for infant digestive systems. Breastfed infants are sick less often than bottle-fed infants. Breastfeeding is more sustainable and results in less plastic waste and other trash. Breastfeeding can also save families money because it does not incur the exact cost of purchasing formula. Other benefits include that breast milk is always ready. It does not have to be mixed, heated, or prepared. Also, breast milk is sterile and is always at the right temperature.

Besides, the skin-to-skin contact of breastfeeding promotes a close bond between mother and baby, which is an essential emotional and psychological benefit. The practice also provides health benefits for the mother. Breastfeeding helps a woman’s bones stay strong, protecting against fractures later in life. Studies have also shown that breastfeeding reduces the risk of breast and ovarian cancers.

Barriers to Breastfeeding

Although breast milk is ideal for almost all infants, there are some challenges that nursing mothers may face when starting and continuing to breastfeed their infants. These obstacles include painful engorgement or fullness in the breasts, sore and tender nipples, lack of comfort or confidence in public, and accommodation to breastfeed or express milk in the workplace.

One of the first challenges nursing mothers face is learning the correct technique. Improper latching can result in inadequate intake, slowing growth and development. A new mother may take a little time to help her baby correctly latch on to her nipples. However, International Board Certified Lactation Consultants (IBCLCs), OB nurses, and registered dietitians are trained to help new mothers learn the proper technique. Education, the length of maternity leave, and laws to protect public breastfeeding, among other measures, can all help to facilitate breastfeeding for many lactating women and their newborns.

Contraindications to Breastfeeding

Although there are numerous benefits to breastfeeding, there are also risks that must be considered in some cases. A new mother with HIV should not breastfeed in the developed world because the infection can be transmitted through breast milk. These women typically have access to a safe bottled formula and can be used as a replacement for breast milk. However, in developing nations where HIV infection rates are high and acceptable infant formula can be challenging to come by. Many newborns would be deprived of the nutrients they need to develop and grow. Also, inappropriate or contaminated bottle formulas cause 1.5 million infant deaths each year. As a result, the WHO recommends that women infected with HIV in the developing world nurse their infants while taking antiretroviral medications to lower the transmission risk.

Breastfeeding also is not recommended for women undergoing radiation or chemotherapy treatment for cancer. Additionally, if an infant is diagnosed with galactosemia, meaning an inability to process the simple sugar galactose, the child must be on a galactose-free diet, excluding breast milk. However, this genetic disorder is a rare condition and only affects 1 in thirty- to sixty thousand newborns. When breastfeeding is contraindicated for any reason, feeding a baby formula enables parents and caregivers to meet their newborn’s nutritional needs.

Breast Milk versus Bottle Formula

Breast Milk Bottle Formula
Antibodies and lactoferrin in breast milk protect infants. The formula does not contain immunoprotective factors.
The iron in breast milk is absorbed more easily. The formula contains more iron than breast milk, but it is not absorbed as easily.
The feces that babies produce do not smell because breastfed infants have different bacteria in the gut. The feces that bottle-fed infants produce tend to have a foul-smelling odor.
Breast milk is always available and is always at the correct temperature. The formula must be prepared, refrigerated for storage, and warmed before giving to an infant.
Breastfed infants are less likely to have constipation. Bottle-fed infants are more likely to have constipation.
Breastfeeding is free, though purchasing a pump and bottles to express milk does require some expense. A formula must be purchased and is expensive.
Breast milk contains DHA and ARA’s fatty acids, which are vital for brain and vision development. Some formulas contain DHA and ALA.

Infancy (Birth to Age One)

Several significant physiological changes occur during infancy. The body’s trunk grows faster than the arms and legs, while the head becomes less prominent than the limbs. Organs and organ systems grow at a rapid rate. Also, during this period, countless new synapses form to link brain neurons. Two soft spots on the baby’s skull, known as fontanels, allow the skull to accommodate rapid brain growth. The posterior fontanel closes first, by the age of eight weeks. The anterior fontanel closes about a year later, at eighteen months on average. Developmental milestones include sitting up without support, learning to walk, teething, and vocalizing, among many others. These changes require adequate nutrition to ensure development at the appropriate rate.

Healthy infants grow steadily but not always at an even pace. For example, during the first year of life, height increases by 50 percent, while weight triples. Physicians and other health professionals can use growth charts to track a baby’s development process. Because infants cannot stand, the length is used instead of height to determine a child’s growth rate. Other vital developmental measurements include head circumference and weight. These must be tracked and compared against standard measurements for an infant’s age.

For infants and toddlers from birth to 24 months of age, the World Health Organization (WHO) growth charts monitor growth. These standards represent optimal growth for children at this age and track growth trends over time through percentile rankings. Growth charts may warn that a child has a medical problem or is malnourished. Insufficient weight or height gain during infancy may indicate a condition known as failure-to-thrive (FTT), characterized by poor growth. FTT can happen at any age, but it typically occurs after six months in infancy. Some causes include poverty, lack of food, inappropriate feeding foods, and excessive fruit juice intake.

Nutritional Requirements

On a per-kilogram basis, requirements for macronutrients and micronutrients are higher during infancy than at any other stage in the human life cycle. These needs are affected by the rapid cell division during growth, which requires energy and protein, and the nutrients involved in DNA synthesis. A baby’s resting metabolic rate is two times that of an adult. Children are entirely dependent on their parents or other caregivers during this period to meet these needs. Breast milk is the best source for almost all infants six months or younger to fulfill nutritional requirements. An infant may require feedings eight to twelve times a day or more initially. After six months, infants can gradually consume solid foods to help meet nutrient needs.

Energy and Macronutrients

The dietary recommendations for infants are based on the nutritional content of human breast milk. Carbohydrates make up about 45 to 65 percent of the caloric content in breast milk, which amounts to an RDA of about 130 grams. Almost all carbohydrates in human milk are lactose, which infants digest and tolerate well. Lactose intolerance is practically nonexistent in infants. Protein makes up about 5 to 20 percent of breast milk’s caloric content, which amounts to 13 grams per day. Infants have a high need for protein to support growth and development. However, excess protein (which is only a concern with bottle-feeding) can cause premature infants’ dehydration, diarrhea, fever, and acidosis. About 30 to 40 percent of the caloric content in breast milk is fat. A high-fat diet is necessary to encourage neural pathways in the brain and other body parts. However, saturated fats and trans fatty acids inhibit this growth. Infants over the age of six months, which means they are no longer exclusively breastfed, should not consume foods high in these types of fats.


Almost all of the nutrients that infants require can be met if they consume adequate breast milk. There are a few exceptions, though. Human milk is low in vitamin D, which is needed for calcium absorption and building bone, among other things. Therefore, breastfed children often need to take a vitamin D supplement in the form of drops. Infants at the highest risk for vitamin D deficiency have darker skin and no sunlight exposure. Breast milk is also low in vitamin K, required for blood clotting, and deficits could lead to bleeding or hemorrhagic disease. Babies are born with little vitamin K so supplementation may be needed initially, and some states require a vitamin K injection after birth. Also, breast milk is not high in iron, but infants absorb the iron in breast milk. However, after four to six months, an infant needs an additional iron source other than breast milk.


Infants have a high need for fluids, 1.5 milliliters per kilocalorie consumed, then 1.0 milliliters per kilocalorie consumed for adults. This is because children have a larger body surface area per unit of body weight and a reduced perspiration capacity. Therefore, they are at greater risk of dehydration. However, parents or other caregivers can meet an infant’s fluid needs with breast milk or formula. As solids are introduced, parents must ensure that young children continue to drink fluids throughout the day.


Most women can and should breastfeed when given sufficient education and support. However, as discussed, a small percentage of women cannot breastfeed their infants, while others choose not to. For parents who choose to bottle-feed, infant formula provides a balance of nutrients. However, not all formulas are the same, and there are important considerations that parents and caregivers must weigh. Standard formulas use cow’s milk as a base. They have 20 calories per fluid ounce, similar to breast milk, with vitamins and minerals added. Soy-based formulas are usually given to infants who develop diarrhea, constipation, vomiting, colic, abdominal pain, or infants with a cow’s milk protein allergy. Hypoallergenic protein hydrolysate formulas are usually given to infants allergic to cow’s milk and soy protein. This type of formula uses hydrolyzed protein, which is broken down into amino acids and small peptides, making it easier to digest. Preterm infant formulas are given to low birth weight infants if breast milk is unavailable. Preterm infant formulas have 24 calories per fluid ounce and are given until they reach the desired weight.

Infant formula comes in three basic types:

  1. Powder that requires mixing with water. This is the least expensive type of formula.
  2. Concentrates, which are liquids that must be diluted with water. This type is slightly more expensive.
  3. Ready-to-use liquids that can be poured directly into bottles. This is the most expensive type of formula. However, it requires the least amount of preparation. Ready-to-use formulas are also convenient for traveling.

Most babies need about 2.5 ounces of formula per pound of body weight each day. Therefore, the average infant should consume about 24 fluid ounces of breastmilk or formula per day. Parents and caregivers should carefully follow the safety guidelines when preparing formula since an infant has an immature immune system. All equipment used in formula preparation should be sterilized. A prepared, new formula should be refrigerated to prevent bacterial growth. Parents should not use contaminated water to mix formula to avoid foodborne illnesses. Follow the powdered and concentrated formula instructions carefully—an overly diluted formula would not provide adequate calories and protein. Simultaneously, an extremely concentrated formula provides too much protein and too little water, impairing kidney function. It is important to note that both the American Academy of Pediatrics and the WHO state that breast milk is far superior to infant formula.

Introducing Solid Foods

According to the WHO, infants should be breastfed or bottle-fed exclusively for the first six months of life. (The American Academy of Pediatrics recommends breast milk or bottle formula exclusively for at least the first four months, but ideally for six months.) Infants should not consume solid foods before six months because solids do not contain the right nutrient mix that infants need. Also, eating solids may mean drinking less breast milk or bottled formula. If that occurs, an infant may not consume the right quantities of various nutrients. If parents try to feed an infant who is too young or is not ready, their tongue will push the food out, called an extrusion reflex. After six months, the suck-swallow reflexes are not as strong, and infants can hold up their heads and move them around, both of which make eating solid foods more feasible.

Solid baby foods can be bought commercially or prepared from regular food using a food processor, blender, food mill, or grinder at home. By nine months to a year, infants can chew soft foods and eat well chopped or mashed solids. Infants fed solid foods too soon are susceptible to developing food allergies. Therefore, as parents and caregivers introduce solids, they should feed their child only one new food at a time to help identify allergic responses or food intolerances. An iron supplement is also recommended at this time.

When to Introduce Solid Foods

Learning to Self-Feed

With the introduction of solid foods, young children learn how to handle food and feed themselves. At six to seven months, infants can use their whole hand to pick up items (this is known as the palmer grasp). They can lift larger things, but picking up smaller pieces of food is difficult. At eight months, a child might use a pincer grasp, which uses fingers to pick up objects. After one, children slowly begin to use utensils to handle their food. Unbreakable dishes and cups are essential since very young children may play with them or throw them when they become bored with their food.

Food Allergies

Food allergies impact four to six percent of young children in America. Common food allergens include peanuts, eggs, shellfish, wheat, and cow’s milk. However, lactating women should not make any changes to their diets. Research shows that nursing mothers who attempt to ward off allergies in their infants by eliminating certain foods may do more harm than good. According to the American Academy of Allergy, Asthma, and Immunology, mothers who avoided certain dairy products showed decreased levels in their breast milk of an immunoglobulin specific to cow’s milk. This antibody is thought to protect against the development of allergies in children. Even when an infant is at higher risk for food allergies, there is no evidence that alterations in a mother’s diet make a difference. It is possible that continuing breastfeeding when introducing solid foods in the infant diet may be preventative. There is currently no scientific evidence indicating that the introduction of solid foods is preventive for delayed (after six months of age) or early (before four months of age). However, there is evidence that introducing solid foods after 17 weeks of age is associated with a decreased risk of developing food allergies.

Early Childhood Dental Caries

Primary teeth are at risk for a disorder known as early childhood caries from breast milk, formula, juice, or other drinks fed through a bottle. Early childhood caries are caused by the kinds of liquids given to an infant and the frequency and length of time that fluids are given. Liquids can build up in a baby’s mouth, and the natural or added sugars lead to decay. Giving a child a bottle of juice or other sweet drinks several times each day or letting a baby suck on a bottle longer than a mealtime, either when awake or asleep, can also cause early childhood caries. Besides, this practice affects the teeth and jaw development and position. Early child caries’ risk continues into the toddler years as children consume more foods with high sugar content. Therefore, parents should avoid giving their children sugary snacks and beverages.

Learning Objectives

  • Identify the nutrient needs of an infant. (MCCCD Competency 9)
  • Explain the benefits of breastfeeding.(MCCCD Competency 5)
  • Discuss the use of bottled formulas(MCCCD Competency 5)
  • Learn when to introduce solid foods to your infant. (MCCCD Competency 8)
  • Learn how to identify food allergies. (MCCCD Competency 4)
  • Identify which foods create dental caries. (MCCCD Competency 4)



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Nutrition Essentials Copyright © 2020 by Stephanie Green and Kelli Shallal is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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