CHAPTER 1: NUTRITIONAL NEEDS OF INFANTS - Free Download PDF

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CHAPTER 1: NUTRITIONAL NEEDS OF INFANTSIntroductionNutrition AssessmentGood nutrition is essential for the growth anddevelopment that occurs during an infant’s firstyear of life. When developing infants are fed theappropriate types and amounts of foods, theirhealth is promoted. Positive and supportivefeeding attitudes and techniques demonstratedby the caregiver help infants develop healthyattitudes toward foods, themselves, and others.To determine an infant’s nutritional needsand develop a nutrition care plan, an accurateassessment of the infant’s nutritional statusmust be performed. The nutrition assessmentprovides the nutritionist or health counselorwith important feeding practices and otherinformation pertinent to an infant’s health.Nutrition education sessions can then bedesigned to encourage positive, appropriatefeeding practices and, if necessary, recommendstrategies to correct inappropriate practices. Bycommunicating periodically with a caregiverabout an infant’s nutritional needs in the first yearof life, better care for the infant is assured.Throughout the first year, many physiologicalchanges occur that allow infants to consumefoods of varying composition and texture. Asan infant’s mouth, tongue, and digestive tractmature, the infant shifts from being able toonly suckle, swallow, and take in liquid foods,such as breast milk or infant formula, to beingable to chew and receive a wide variety ofcomplementary foods. See Chapter 5, page 101,for more information regarding complementaryfoods. At the same time, infants progress fromneeding to be fed to feeding themselves. Asinfants mature, their food and feeding patternsmust continually change.For proper growth and development, an infantmust obtain an adequate amount of essentialnutrients by consuming appropriate quantitiesand types of foods. During infancy, a period ofrapid growth, nutrient requirements per pound ofbody weight are proportionally higher than at anyother time in the life cycle. Although there aremany nutrients known to be needed by humans,requirements have been estimated for only alimited number of these.This chapter includes sections on nutritionassessment, the Dietary Reference Intakes (DRIs),and background information on importantnutrients needed during infancy. Counselingpoints that relate to the information presentedin this chapter are found in Chapter 8, pages157–158.The assessment should include an examination of: Health and medical information –Information gathered through chartreview, caregiver interview, health careprovider referral form(s), or other sourcesthat may include history of chronic oracute illnesses or medical conditions, birthhistory, developmental disabilities, a clinicalassessment identifying signs of nutritionaldeficiencies, and other pertinent information(e.g. immunization record);1, 2 Dietary intake data:1, 3 Feeding history – Eating behaviors, feedingtechniques, feeding problems, andenvironment; Appetite and intake – Usual appetite,factors affecting intake such as preferences,allergies, intolerances, chewing/swallowingproblems, feeding skills; Diet history – Breastfed and/or infantformula-fed; frequency and duration ofbreastfeeding; frequency and amount ofinfant formula or complementary foodsfed; age at introduction of complementaryfoods; variety of complementary foodsprovided; vitamin/mineral or otherINFANT NUTRITION AND FEEDING11

supplements given; and problems such asvomiting, diarrhea, constipation, or colic;and Socioeconomic background – Primary andother caregivers, food preparation andstorage facilities, use of supplementalfeeding and financial assistance programs,access to health care, and ethnic and/orcultural influences on the diet.1 Anthropometric Data – Anthropometricmeasurements, i.e., weight for age, lengthfor age, weight for length, and headcircumference for age;1 and Biochemical Data – Data used to diagnose orconfirm nutritional deficiencies or excesses;1,4in the WIC Program, hemoglobin, hematocrit,or other hematological tests are performed toscreen for iron deficiency anemia.Dietary Reference Intakes (DRIs)The Dietary Reference Intakes (DRIs), developedby the Institute of Medicine’s Food and NutritionBoard, are four nutrient-based reference valuesintended for planning and assessing diets. Theyinclude the Estimated Average Requirement(EAR), the Recommended Dietary Allowance(RDA), the Adequate Intake (AI), and theTolerable Upper Intake Level (UL).5Recommendations for feeding infants, frominfant formula to complementary foods, are basedprimarily on the DRIs. The DRIs for infants arebased on the nutrient content of foods consumedby healthy infants with normal growth patterns,the nutrient content of breast milk, investigativeresearch, and metabolic studies. It is difficult todefine precise nutrient requirements applicable toall infants because each infant is unique. Infantsdiffer in the amount of nutrients ingested andstored, body composition, growth rates, andphysical activity levels. Also infants with medicalproblems or special nutritional needs (such asmetabolic disorders, chronic diseases, injuries,premature birth, birth defects, other medicalconditions, or being on drug therapies) may havedifferent nutritional needs than healthy infants.The DRIs for vitamins, minerals, and proteinare set at levels thought to be high enough tomeet the nutrient needs of most healthy infants,while energy allowances, referred to as EstimatedEnergy Requirement (EER), are based on averagerequirements for infants. See page 15 for moreinformation regarding EER.See Appendix A, pages 180–182, for a completetable of DRIs for infants.Important NutrientsThe following sections include informationon the food sources, functions, and concernsregarding major nutrients and nutrientsconsidered to be of public health significanceto infants in the United States.For additional information on the function,deficiency and toxicity symptoms, and major foodsources of the nutrients discussed below, as well as EAR is the median usual intake that is estimated to meet the requirement of half of the healthypopulation for age and gender. At this level of intake, half the individuals will have their nutrientneeds met. The EAR is used to establish the RDA and evaluate the diet of a population. RDA is the average dietary intake level sufficient to meet the nutrient requirement of nearly all(97–98 percent) healthy individuals. If there is not enough scientific evidence to establish an EARand set the RDA, an AI is derived. AI represents an approximation of intake by a group of healthy individuals maintaining a definednutritional status. It is a value set as a goal for individual intake of nutrients that do not have aRDA. UL is the highest level of ongoing daily intake of a nutrient that is estimated to pose no risk in themajority of the population. ULs are not intended to be recommended levels of intake, but theycan be used as guides to limiting intakes of specific nutrients.12INFANT NUTRITION AND FEEDING

other nutrients not discussed, refer to AppendixC: Nutrient Chart: Function, Deficiency andToxicity Symptoms, and Major Food Sources ofNutrients, pages 190–194.EnergyEnergy NeedsInfants need energy from food for activity,growth, and normal development. Energy comesfrom foods containing carbohydrate, protein, orfat. The number of kilocalories (often termed“calories”) needed per unit of a person’s bodyweight expresses energy needs. A kilocalorie isa measure of how much energy a food suppliesto the body and is technically defined as thequantity of heat required to raise the temperatureof 1 kilogram of water 1 degree Celsius. Aninfant’s energy or caloric requirement dependson many factors, including body size andcomposition, metabolic rate (the energy the bodyexpends at rest), physical activity, size at birth,age, sex, genetic factors, energy intake, medicalconditions, ambient temperature, and growthrate. Infants are capable of regulating their intakeof food to consume the amount of kilocaloriesthey need. Thus, caregivers are generally advisedto watch their infants’ hunger and satiety cuesin making decisions about when and how muchto feed. See Table 2, page 46; Figure 1, page42; page 59; page 87; and page 123 for moreinformation regarding hunger and satiety cues.Recommended Energy AllowancesThe World Health Organization’s (WHO) expertreport on energy and protein requirements states: 6The energy requirement of an individual is alevel of energy intake from food that will balanceenergy expenditure when the individual has abody size and composition and level of physicalactivity, consistent with long-term good health;and that would allow for the maintenance ofeconomically necessary and socially desirablephysical activity. In children and pregnant orlactating women the energy requirement includesthe energy needs associated with the deposition oftissues or the secretion of milk at rates consistentwith good health.Using this rationale, the Institute of MedicineFood and Nutrition Board has determinedthat the EER for infants should balance energyexpenditure at a level of physical activityconsistent with normal development and allowfor deposition of tissues at a rate consistentwith health. See Table 1, page 15, for the EER,reference weights, and reference lengths forinfants. Modification of these requirements maybe required based on individual needs and growthpatterns.7 The kilocalories needed per unit ofbody weight decrease over the first year becauseinfants older than 6 months grow more slowly.Energy Intake and Growth RateA general indicator of whether an infant isconsuming an adequate number of kilocaloriesper day is the infant’s growth rate in length,weight, and head circumference. However,physical growth is a complex process that can beinfluenced by size and gestational age at birth,environmental and genetic factors, and medicalconditions, in addition to dietary intake. Aninfant’s growth rate can be assessed by periodicallyplotting the infant’s weight, length, and headcircumference for age and weight for length onCenters for Disease Control (CDC) growth chartsthroughout the first year of life. See AppendixB: Use and Interpretation of CDC GrowthCharts, pages 183–189. Appendix B includesbasic instructions on how to collect, record, andinterpret weight, length, and head circumferencemeasures and the CDC WIC growth charts forinfants. Refer to Kleinman,8 Lucas,9 NationalCenter for Chronic Disease Prevention andHealth Promotion,10 and reference textbooks onpediatric nutrition or nutrition assessment formore detailed information on the anthropometricassessment of infants.In general, most healthy infants double theirbirth weight by 6 months of age and triple it by12 months of age.11 However, keep in mind thatthere are normal differences in growth betweenhealthy breastfed and formula-fed infants duringthe first year of life. After 3 months of age, therate of weight gain in the breastfed infant maybe lower than that of formula-fed infants, butINFANT NUTRITION AND FEEDING13

differences are generally not reported betweenthese infants for length and head circumference.12Ultimately, each infant’s growth must beindividually assessed.In addition to health and medical information,anthropometric data, and biochemical data, thenutrition assessment of an infant should includean evaluation of breastfeeding frequency andduration, infant formula dilution and intake,appropriate amount and types of complementaryfoods, and feeding skill development. For moreinformation regarding nutrition assessment seepages 11–12. Assessing this dietary intake datawill be helpful in determining which factorsare influencing the growth rate if an infant’sgrowth per the CDC growth charts appears tobe abnormally slow or rapid. For infants withan abnormal rate of growth, assess the feedingrelationship for negative interactions associatedwith feeding that may be contributing. For moreinformation on the feeding relationship refer topage 45. Infants with abnormally slow or rapidgrowth rates or recent weight loss should bereferred to a health care provider for assessment.CarbohydratesAI for Infants0–6 months7–12 months60 g/day of carbohydrate95 g/day of carbohydrateCarbohydrates fall into these major categories:simple sugars or monosaccharides (e.g., glucose,galactose, fructose, and mannose), doublesugars or disaccharides (e.g., sucrose, lactose,and maltose), and complex carbohydrates orpolysaccharides (e.g., starch, dextrins, glycogen,and indigestible complex carbohydrates suchas pectin, lignin, gums, and cellulose). Dietaryfiber is another name for indigestible complexcarbohydrates of plant origin (these are notbroken down by intestinal digestive enzymes).Sugar alcohols, including sorbitol and mannitol,are also important to consider for infants.FunctionsCarbohydrates are necessary in the infant’s dietbecause they: Supply food energy for growth, bodyfunctions, and activity; Allow protein in the diet to be used efficientlyfor building new tissue; Allow for the normal use of fats in the body;and Provide the building blocks for some essentialbody compounds.Carbohydrates serve as primary sources of energyto fuel bodily activities while protein and fat areneeded for other essential functions in the body,such as building and repairing tissues.SourcesThe major type of carbohydrate normallyconsumed by young infants is lactose, thecarbohydrate source in breast milk and cow’smilk-based infant formula. Lactose-free infantformulas, such as soy-based infant formulas,provide carbohydrates in the form of sucrose,corn syrup, or corn syrup solids. These infantformulas are prescribed to infants who cannotmetabolize lactose or galactose, a component oflactose. Some specialty infant formulas containother carbohydrates in the form of modified cornstarch, tapioca dextrin, or tapioca starch.In later infancy, infants derive carbohydrates fromadditional sources including cereal and othergrain products, fruits, and vegetables. Infantswho consume sufficient breast milk or infantformula and appropriate complementary foodslater in infancy will meet their dietary needs forcarbohydrates.Carbohydrates in Fruit JuicesSome fruit juices, such as prune, apple, andpear, contain a significant amount of sorbitoland proportionally more fructose than glucose.Infants can absorb only a portion of the sorbitol(as little as 10 percent) and fructose in thesejuices.13 Unabsorbed carbohydrate is in these14INFANT NUTRITION AND FEEDING

Table 1 – Estimated Energy Requirements (EER) of Infants(Based on the 2000 Dietary Reference Intakes)MalesAge (mo)123456789101112Reference Weight Reference Weight Reference Length Reference Length Estimated 46793817844FemalesAge (mo)123456789101112Reference Weight Reference Weight Reference Length Reference Length Estimated 717742768INFANT NUTRITION AND FEEDING15

juices.13 Unabsorbed carbohydrate is fermentedin the lower intestine causing diarrhea,abdominal pain, or bloating. These symptomsare commonly reported in infants and toddlerswho drink excessive amounts of juice. For thisand other reasons, infants up to 6 months ofage should not be offered fruit juice; infantsover 6 months should be offered no more than4 to 6 ounces daily of pasteurized, 100 percentjuice from a cup.14 See pages 107–108 for moreinformation regarding infants and fruit juice.Fermentable carbohydrates also contribute to thedevelopment of tooth decay. See pages 131–132for information regarding the role of certaincarbohydrates in tooth decay.FiberDietary fiber is found in legumes, wholegrain foods, fruits, and vegetables. Breast milkcontains no dietary fiber, and infants generallyconsume no fiber in the first 6 months of life. Ascomplementary foods are introduced to the diet,fiber intake increases; however, no AI for fiber hasbeen established. It has been recommended thatfrom 6 to 12 months whole-grain cereals, greenvegetables, and legumes be gradually introducedto provide 5 grams of fiber per day by 1 year ofage.15 See pages 136–139 for more information onvegetarian diets, where fiber intake may be high.ProteinAI for Infants0–6 monthsRDA for older infants7–12 months9.1 g/day of protein11 g/day of proteinAll proteins are combinations of about 20common amino acids. Some of these amino acidsare manufactured in the body when adequateamounts of protein-rich foods are eaten. Nineamino acids that are not manufactured by thehuman body and must be supplied by the diet arecalled “essential” or “indispensable” amino acids.These include: histidine, isoleucine, leucine,lysine, methionine, phenylalanine, threonine,tryptophan, and valine. Two other amino acids,cystine and tyrosine, are considered essential16INFANT NUTRITION AND FEEDINGfor the preterm and young term infant becauseenzyme activities involved in their synthesis areimmature.16FunctionsInfants require high quality protein from breastmilk, infant formula, and/or complementaryfoods that: Build, maintain, and repair new tissues,including tissues of the skin, eyes, muscles,heart, lungs, brain, and other organs; Manufacture important enzymes, hormones,antibodies, and other components; and Perform very specialized functions inregulating body processes.Protein also serves as a potential source of energyif the diet does not furnish sufficient kilocaloriesfrom carbohydrate or fat. As with energy needs,protein needs for growth per unit of body weightare initially high and then decrease with age asgrowth rate decreases.DRIs for ProteinThe DRIs for protein were devised based onthe intake of protein from breast milk forthe exclusively breastfed infant 0–6 monthsold.16 Infant formula provides higher amountsof protein than breast milk, but the proteinis not used as efficiently. The contribution ofcomplementary foods to total protein intake inthe second 6 months of infancy was considered inestablishing the RDA for this age.SourcesBreast milk and infant formulas providesufficient protein to meet a young infant’sneeds if consumed in amounts necessary tomeet energy needs. In later infancy, sources ofprotein in addition to breast milk and infantformula include meat, poultry, fish, egg yolks,cheese, yogurt, legumes, and cereals and othergrain products. When an infant starts receivinga substantial portion of energy from foodsother than breast milk or infant formula, thesecomplementary foods need to provide adequateprotein. See pages 109–111 for information

regarding the introduction protein-richcomplementary foods into an infant’s diet.Proteins in animal foods contain sufficientamounts of all the essential amino acids neededto meet protein requirements. In comparison,plant foods contain low levels of one or more ofthe essential amino acids. However, when plantfoods low in one essential amino acid are eatenon the same day with an animal food or otherplant foods that are high in that amino acid (e.g.,legumes such as pureed kidney beans [low inmethionine, high in lysine] and grain productssuch as mashed rice [high in methionine, low inlysine]), sufficient amounts of all the essentialamino acids are made available to the body.17The protein eaten from the two foods would beequivalent to the high-quality protein found inanimal products. See page 137 regarding proteinconcerns in vegetarian diets.Protein DeficiencyIn developing countries, infants who are deprivedof adequate types and amounts of food forlong periods of time may develop kwashiorkor,resulting principally from a protein defici

Nutrition Assessment To determine an infant’s nutritional needs and develop a nutrition care plan, an accurate assessment of the infant’s nutritional status must be performed. The nutrition assessment provides the nutritionist or health counselor with important feeding practices and other information pertinent to an infant’s health.