1 Infant Nutrition Ala K. Shaikhkhali, MD Maria Mascarenhas, MDThe Children’s Hospital of Philadelphia Reviewed by Sandeep Gupta, MD of the Professional Education Committee
2 Objectives Normal growth patterns in infancyNutritional requirements of healthy term infants* Macronutrients Micronutrients Benefits of human-milk Practical guidelines for complementary feeding Summary *Please note that this slide set is not intended to discuss issues pertaining to preterm infant nutrition or nutrition in infants with chronic medical conditions
3 Case Presentation A mother brings in her 2 month old healthy term infant who is exclusively breast fed for a well visit How would you answer these nutritional questions: Can she eat cereal now? Mom heard that human-milk has less iron than formula, should the baby be on an iron supplement? What about other supplements? How fast should she be growing? When will she double, triple her birth weight? Mom heard that human-milk has much less iron than formula
4 Growth Patterns in Infancy
5 Growth Patterns in InfancyThe first year of life is a period of very rapid growth - Healthy 1 month old gains~ 1 cm/week and g/day - By 12 months of age gains 0.5 cm/week and 10 g/day Average newborn weight is 3.5 kg, weight is doubled by 4-6 months and tripled by 12 months Nutrition during infancy can influence risk factors for disease in adult life * Nutrition during infancy is not only important for growth and development but has also been shown to influence risk factors for disease in adult life l O’Hara, Georgina The World of the Baby: A Celebration of Infancy through the Ages. New York, NY: Doubleday. Fun Fact: If a person who was born 8 lbs. and 20 in. at birth continued growing at the same rate as he does the first year, by the time he reached 20, he’d be 25 ft. tall and weigh nearly 315 lbs!
6 Growth Charts April 2006 WHO international growth charts** Growth standard – describe growth of healthy children in optimal conditions (e.g. exclusive breastfeeding for 4 mo, continued to 12 mo) Includes children 0-20 yrs AAP recommends using WHO growth charts between 0-24 mo May 2000 Chronic Disease Prevention and Health Promotion and Center for Disease Control* Growth reference –how children grew in a particular place and time Includes children 0 to 20 years of age AAP recommend susing CDC growth charts between 2 and 20 yrs Both growth charts include Weight, length/height, head circumference, body mass index for age AAP Recommendations Normal growth reflects nutritional status and overall wellbeing; poor growth is always a cause for concern and should be evaluated promptly
7 Development of Feeding AbilitiesNeonates have instinctive sucking reflexes Things touching the infant’s palate (nipple or finger) will trigger the sucking reflex At one year, infants can chew soft foods and swallow easily WHO recommends exclusive breast feeding for children until 6 months of age, followed by introduction of soft complementary foods with continued breast feeding
8 Development of Renal CapacityEarly in infancy, high protein load will cause renal overload and osmotic diuresis leading to dehydration The kidneys of a healthy term infant can excrete urea, sodium, and other solutes load that is present in human-milk or infant formula Renal Solute Load per 100 kcal human-milk 14 mOsm Infant formula 20 mOsm Cow’s milk 46 mOsm Infants should not receive cow’s milk
9 Summary The first year of life is a period of very rapid growthSuboptimal growth is always a cause of concern Infants have limited gastrointestinal and renal capacities human-milk or iron-fortified formula should be the sole source of nutrition during the first 4-6 months of life Physiological changes in the gut enable the infant to progress from digesting only milk to digesting complex foods by one year
10 Breast Feeding and Infant Formula
11 Breast Feeding AAP recommends human-milk as the feeding of choice for infants whenever possible* Successful breast feeding require a supportive environment for the mother Nutrient needs of term infants from birth to 6 months of age are met with human-milk as a source of exclusive nutrition (with few exceptions)** Success of breast feeding is demonstrated when infant has feedings 8-12 times per day, at least 6-8 wet diapers, regular stools, and growth along established growth curves On average human-milk provides 20 calories/oz *Contraindications to breast feeding include maternal infections HIV, exposure to drug, food, or environmental agent that could be harmful and in infants who have certain inborn errors of metabolism ** Most of the nutritional needs are met by human-milk or formula. Guidelines are present on vitamin K, D, iron, and fluoride * Breast feeding should be offered as early as possible after birth and then every 2 to 3 hours for approximately minutes per breast for the first few weeks *Less frequent feeding may occur once breast feeding is established *Intervals of more than 5 hours should be avoided during the first few weeks
12 human-milk vs. Infant FormulaBenefits of breast feeding over infant formula are well established: Enhanced motility and maturity of the GI tract Maternal infant bonding Monetary saving Facilitated fat, protein, and carbohydrate digestion and absorption Passive immunity Improved cognitive development Decreased incidence of respiratory and GI disease Further potential benefits are decreased risk of overweight, cardiovascular disease, and ? Type I DM
13 Infant Formula When human-milk is not available, iron fortified infant formula is the appropriate alternative There are continued efforts to evolve infant formula to be closer to composition of human-milk Addition of DHA and ARA* is a recent example Multiple studies in term and preterm infants showed significantly lower levels of DHA and ARA in RBC of infants who are formula fed Some studies suggested short term improvement in vision and cognitive functions DHA is Docosahexaeonic acid and ARA is Arachidonic acid
14 Nutritional Requirements of Healthy Term InfantsNutrient requirements for first 6 months are based on composition of human-milk From 6 months to one year of age, RDA assume the composition of infant formula and increasing amounts of solid food
15 Macronutrients Energy Fluid Carbohydrate Fat Protein
16 Energy Requirements Expressed per unit of body weight, estimated energy requirements of a normal newborn is more than a normal adult kcal/kg/day vs kcal/kg/day in adults Reflection of higher metabolic rate and energy needs for growth and development Studies show that infants consume markedly higher energy intakes during the early months of life Data also show that formula-fed infants consume more energy than breast-fed infants* Gender differences are small but consistently present * Which, at least partially, explains the somewhat more rapid growth of formula-fed infants and thus the need for growth charts that represent breast fed infants.
17 Fluid Requirements Necessary to replace losses (skin, lungs, feces, and urine) and for growth human-milk and infant formula* provide ~ 89 ml of water in each 100 ml Fluid needs: 1 to 10 kg: 100 mL/kg/day * Of conventional energy density (20 calorie/Oz)
18 Carbohydrates Comprise 35 to 65% of total energy intake of term infants Usually as disaccharides or glucose polymers Glucose is the principal nutrient the neonatal brain utilizes Inadequate carbohydrate intake can lead to hypoglycemia, ketosis, and excessive protein catabolism
19 Fat American Academy of Pediatrics recommends 30-55% of total energy be from fat and 2.7% be of linoleic acid Adults should consume ~20-35% of energy from fat Fat serves many roles: A concentrated source of energy Carries fat- soluble vitamins Provides essential fatty acids Important for brain and organ growth Essential fatty acids are precursors for synthesis of prostaglandins and have other essential functions Table 5-4 Heimberger for different fat profile of rbeast milk and cow milk
20 Protein AAP recommends that 7-16% of total energy be from protein or g/kg/day Protein provides nitrogen and amino acids Synthesis of tissues, enzymes, hormones, and antibodies that regulate and perform physiologic and metabolic functions Excess dietary proteins are metabolized for energy Producing urea that increases the renal solute load, water requirements, and the risk of dehydration Healthy term infants may grow well with a protein intake (from human-milk) slightly below 1.6 g/kg/day
21 Protein Protein in most commercial infant formulas typically comes from cow milk Cow’s milk based infant formula whey/casein ration of 20:80 human-milk whey/casein ration is ~70:30 Some recently developed formulas have a ratio 60:40 The curd formed from whey in an acidic stomach is soft, easily digestible, and emptied quickly Table 5-3 for protein compsition comparison
22 Protein Other protein sources in infant formula include Soy proteinProtein hydrolysates Free amino acid formulas are also available for infants with cow’s milk protein allergy who are unable to tolerate protein hydrolysates
23 Micronutrients In this section, we will discuss select vitamins and minerals that are pertinent to infant nutrition in board review related conditions Others are beyond the scope of this talk
24 Iron Unless mother has iron deficiency, term infants are usually born with iron stores enough for the first 6 months human-milk contains less iron than formula, but that iron is more bioavailable- so breast fed infants should not need iron supplementation routinely After the age of six months, iron content in human-milk is no longer enough and complementary foods should include iron (fortified cereal, meat)
25 Vitamin D Human-milk vitamin D content is low, breast fed infants should receive vitamin D supplementation at 400 IU daily Formula fed infants who receive a minimum of 1000 ml daily do not need vitamin D supplementation Risk factors for vitamin D deficiency: dark skin color, maternal vitamin D deficiency, and recommended lack of direct sun exposure <6 months of age Vitamin D deficiency can result in metabolic abnormalities and rickets 2008 AAP recommendations
26 Fluoride From birth to 6 months, infants need very little fluoride and are at risk of fluorosis with excessive intake Human-milk contains very little fluoride and there is no risk of fluorosis In formula fed infants, it is recommended to use ready to feed formula or water with low mineral content (purified, distilled, etc) Infants above 6 months of age should receive fluoride supplementation only if they live in areas with non-fluoridated water
27 Folate/Vitamin B12 & Vitamin KInfants of vegan mothers who are breast fed should be monitored for vitamin B12 deficiency Folate deficiency is a risk in infants receiving large amounts of goat milk or powdered milk The sterile digestive tract of newborn infants does not contain vitamin K-producing bacteria and they require a dose of vitamin K at birth A newborn has a limited capacity for nutrient interconversion, which makes some nutrients conditionally essential
28 Complementary FeedingComplementary food provides micronutrients that infants beyond 6 months of age need Assess physical and psychological readiness for adding food Introduce one new food every three days Rice cereal is often introduced as the first feeding Introducing meat early provides a rich source of iron and zinc Repeated exposure may be necessary before acceptance
29 Complementary FeedingBy 9 months can add finely chopped and finger foods 12 months infants can chew and progress to table food Avoid choking hazards* Frequency of meals 6-8 months: two-three daily 9-12 months: three-four daily One or two snacks be added Juice is not a necessary component of diet and should be limited Grapes, nuts, popcorn, hard candy, hot dogs
30 Summary Breastfeeding is the normal and by far the preferred method of feeding infants Exclusive breastfeeding is recommended for the first 6 months of life Supplemental vitamin D is recommended for breastfed infants (400 IU daily) When a mother is unable to breastfeed, iron fortified infant formula is the only acceptable alternative First complementary foods should be iron-rich. Routine growth monitoring is important to assess infant health and nutrition
31 Back to Our Case A mother brings in her 2 month old healthy term infant who is being exclusively breast fed for a well visit How would you answer these nutritional questions: Can she eat cereal now? Mom heard that human-milk has less iron than formula, should the baby be on an iron supplement? What about other supplements? How fast should she be growing? When will she double, triple her birth weight? Can she eat cereal now: No the infant is too young for introducing complementary feeding (See complementary feeding slides) Iron supplementation: no, iron supplementation is not routinely required as the iron content of human-milk is more bioavailable than formula Infant will need vitamin D supplementation total 400 IU daily Double weight gain by 4 months, rate of growth at this age grams daily
32 References AAP Pediatric Nutrition Handbook Conn’s Current TherapyNutrition in Medicine Heinberger Handbook of Clinical Nutrition Use of World Health Organization and CDC Growth Charts for Children Aged Months in the United States FROM THE AMERICAN ACADEMY OF PEDIATRICS Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents Nutrition for Healthy Term Infants: Recommendations from Birth to Six Months A joint statement of Health Canada, Canadian Pediatric Society