Pediatric Nutrition for Dietitians

Praveen S. Goday, Cassandra Walia, Praveen S. Goday, Cassandra Walia

• Editore: CRC Press
• Anno: 2022
• ISBN:
  9781000587753
• Edizione: 1
• Argomento: Medicine
• Categoria: Nutrition, Dietics & Bariatrics

Pediatric Nutrition for Dietitians is a comprehensive textbook for undergraduate and graduate dietetics students and an invaluable resource for all dietitians working with children. The book discusses specific nutrient needs of each age group from infancy to adolescence in detail with a focus on the key components of nutrition assessment and intervention. Disease-specific chapters describe the common nutrient-related conditions in childhood and follow the ADIME format used in clinical practice. These chapters are written by clinical experts consisting of a combination of physicians and dietitians. Each disease-specific chapter ends with an ADIME table summarizing nutritional care for the specific population and serves as a quick guide for managing patients. This book provides dietitians with the nutrition assessment and intervention tools needed to adapt to the ever-changing landscape of pediatric nutrition and provide expert nutrition care regardless of the situation.

1 Growth Assessment

Julia Driggers, RD, LDN, CSP; Kanak Verma, MD; and Vi Goh, MD

DOI: 10.1201/9781003147855-1

CONTENTS

1. Infant Growth
2. Childhood Growth
3. Adolescent Growth
4. Measurement of Growth
   1. Weight
   2. Length and Height
   3. Head Circumference
   4. Body Mass Index (BMI)
   5. Mid-Upper Arm Circumference (MUAC)
5. Additional Growth Measurements
   1. Skinfold Thickness
   2. Handgrip Strength
6. Interpreting Growth Measurements
   1. Standard Growth Charts
   2. WHO vs. CDC Growth Charts
   3. Specialty Growth Charts
   4. Z-Scores
7. Additional Growth Assessment Tools
   1. Mid-Parental Height
   2. Ideal Body Weight
   3. Weight Age and Height Age
8. Diagnosis of Underweight and Overweight
9. Bibliography

Nutrition plays a major role in both the physical and intellectual development of children. Monitoring growth and development is a cornerstone of pediatric care. Healthy infants and children typically follow a predictable pattern of development, which allows growth to serve as a sensitive marker for health and nutritional status. Growth can be affected by a variety of conditions, and alterations in growth can be the first sign of a pathologic condition. Marked deviations from a normal growth pattern, particularly during early life, have also been associated with an increased risk of comorbidities later in life. Delayed growth in childhood has been associated with decreased adult height and altered body composition, including increased abdominal fat mass, in adulthood. Further, a substantial body of research has demonstrated that malnutrition can lead to abnormal brain development, including tissue damage, disordered differentiation of neural cells, reduction in synapses and synaptic neurotransmitters, and delayed myelination. These can lead to lasting cognitive impairment, affecting attention, visual, auditory, memory, and executive function, and interfering with a child’s school performance and potential for achievement.

Clinical evaluation of a child’s growth should focus on key historical features, as well as accurate measurement of all growth parameters. The history should include a thorough dietary history, weight, length, and head circumference at birth, prenatal history, past medical and family history, and a complete review of systems for evidence of systemic disease. Body weight, length or height, head circumference, and weight-for-length or body mass index (BMI)-for-age are easily measured or calculated and can be compared with population standards using growth charts (Appendix A). Pediatric growth can be divided into three periods: infancy, childhood, and adolescence.

Infant Growth

The intrauterine environment and maternal nutrition are primarily reflected in the growth parameters at birth and during the first few months of life, after which genetic and environmental factors exhibit a stronger influence. Many infants will significantly change growth percentiles (and hence, their corresponding z-scores) for weight and length during the first 2 years of life, but then usually follow their established growth trajectory after age 2.

Term neonates can lose up to 10% of their birth weight during the first few days of life and should get back to their birth weight by days 10–14. After return to birth weight, infants typically follow an established pattern of weight gain during the first year of life. Expected weight gain during infancy is approximately 30 g/day from age 0 to 3 months, 20 g/day for ages 3 to 6 months, and 10 g/day for ages 6 to 12 months. Infants should roughly double their birth weight by 4 months of age and triple their birth weight by 12 months of age. Weight gain slows after the infant’s first birthday. Normal linear growth in infants is approximately 10 inches (~25 cm) during the first year of life.

Feeding methods can impact the weight gain patterns seen in infants. Breastfed infants typically gain weight more rapidly during the first 3–4 months of life when compared to formula-fed infants, and relatively slowly thereafter. By age 1–2 years, the weights of breastfed and formula-fed infants are similar. It is important to correct growth parameters for gestational age in preterm infants; however, there is limited consensus on the duration of “catch-up” growth in premature infants and how long to correct for gestational age when interpreting growth. The World Health Organization (WHO) suggests correction of weight, height, and head circumference until age 2–3 years for children born prematurely (Chapter 12).

Childhood Growth

Children gain approximately 2 kg/year between age 2 years and puberty. They typically gain 4 inches (~10 cm) in length/height during the second year of life, 3 inches (~7.5 cm) during the third year of life, and 2 inches (~5 cm)/year between age 4 years and puberty. With increasing height and slowed weight gain, toddlers and preschoolers grow taller and leaner. Of note, growth during this period is pulsatile, consisting of periods of rapid growth separated by periods of minimal growth. There is also normal deceleration of height velocity before the pubertal growth spurt during adolescence.

Adolescent Growth

Puberty refers to the physical changes that occur during adolescence, including growth in stature and development of secondary sexual characteristics. The latter occurs in a series of events that also follows a predictable pattern, with some individual variation in sequence and timing of onset (between 8 and 13 years in girls and 9.5 and 14 years in boys). Sexual maturation can happen gradually or with several changes at once. Tanner staging is a sexual maturity rating system used to define physical measures of sexual development, including breast changes in females, genital changes in males, and pubic hair changes in both females and males. Tanner staging is commonly used to define the pre- or peri-pubertal stage of a child at a single point in time (Appendix B). In boys, the first change is testicular development followed by penile growth and pubic hair development. In girls, the first change is breast development followed by the appearance of pubic hair which is then followed by menarche.

Approximately 20% of adult height accrual occurs during puberty, though the pattern of height accrual can be highly variable. It can be steady growth or periods of rapid growth interspersed with periods of slow growth. The typical pubertal growth pattern involves a phase of acceleration, followed by a phase of deceleration, and ending with the eventual cessation of growth with the epiphyseal (growth plate) closure. The timing of the growth spurt varies by sex, occurring 2 years earlier on average in females than in males, and is impacted by sexual development. Therefore, a child’s Tanner staging can provide clues regarding the timing of an expected acceleration in growth.

Peak height velocity is reached in boys between Tanner stages 4 and 5 while in girls it is highest between stages 3 and 4 and is followed by menarche. Menarche can occur between 10 and 16.5 years. After menarche, the average height gain is about 2.75 inches (~7 cm) and can be even greater for girls who menstruate on the early side of normal. Growth typically ceases about 2 years after menarche. Early onset of puberty, and subsequent earlier peak height velocity, can lead to transient periods of tall stature when compared to same-age peers but is typically associated with reduced overall a...