This chapter discusses growth and development during pregnancy and early childhood. It describes how nutrition is essential for fetal growth and development and can have long-term health impacts. Both macronutrients and micronutrients are needed for growth. Maternal undernutrition can lead to low birth weight, intrauterine growth restriction, and increase risk of chronic diseases later in life. The recommended weight gain during pregnancy depends on pre-pregnancy BMI.

1. Chapter Two
Growth and development
By:_ Dr.kedir.N
December; 2019

2. learning Objectives
By the end of the chapter students will be able to;
– Describe role of nutrition in fostering fetal growth &
development, & long-term health
– Identify appropriate weight gain during pregnancy
– Identify nutrient requirements & common nutrition-
related pregnancy problems
– Describe about the Energy Balance & Body
composition

3. Growth and development
• Nutrition is detrimental for growth and
development and maintenance of wellbeing
• Nutrition in early life, a critical period for human
development, can have long-term effects on
health in adulthood.
• For growth human need both
– Macronutrients (proteins, ….) and
– Micronutrients like minerals and vitamins in
adequate amount
PHN lecture notes 3

4. Fetal growth and development
• Nutrition is a key determinant factor for the
maintenance of fetal growth and development
as well as our health status.
• The rate of human growth and development is
higher during gestation than any time after it.
• If the rate of weight gain achieved in 9 months
of gestation continued after delivery.

5. Contin….
• Under nutrition often starts in utero and may
extend throughout the life cycle
• It also spans generations
• A foetus which has experienced IUGR is
unlikely to catch up at the later life, has
increased chance of dying during infancy
• Strong epidemiological evidence suggests a
link between maternal and early childhood
under nutrition increased adult risk of
various chronic diseases
5

6. • Most growth failure occurs before birth until two to
three years of age
• A child who is stunted at three years of age is likely
to remain stunted throughout life
• Apart from the indirect effects on the mother,
micronutrient deficiencies during pregnancy have
serious implications for the developing foetus
– The main micronutrient with significant effect on the
baby include Iodine, vitamin A, and Iron
6

7. The Intergenerational
Cycle of Malnutrition
Child growth failure
Early
pregnancy
Small adult women
Low birth
weight babies
Low weight &
height in teens
ACC/SCN, 1992

8. Wasting or Stunting in utero
• The foetus undergoes its maximum increase in length
at 20-30 weeks of gestation, and in weight during the
third trimester
• Therefore, the timing of undernutrition in utero has
different effects on weight and length
• Stunted (also called symmetrically or proportionately
growth-retarded) infants have a normal ponderal
index (PI) (defined as weight/length3) but their
weight, length, head and abdominal circumferences
are below the 10th percentile of reference values
8

9. • Wasted (asymmetrically or disproportionately
growth retarded) infants have a relatively
normal length and head circumference, but
their body weights and PIs are low due to lack
of fat, and sometimes of lean tissue
• Wasting is thought to result from under
nutrition that occurs late in pregnancy, when
fat deposition is most rapid
• Only 1% of foetal body weight is fat at 26
weeks compared to 12% at 38 weeks.
9

10. Causes of Poor Growth in a Child
• The most common immediate causes of poor growth
of humans in developing countries include:
– Poor maternal nutrition status at conception and
undernutrition in utero;
– Inadequate breastfeeding;
– Delayed complementary feeding,
– Inadequate quality or quantity of
complementary feeding;
– Impaired absorption of nutrients due to
intestinal infections or parasites; or
combinations of these problems
10

11. Nutrition and pregnancy
• During pregnancy all women need more food, a varied
diet and micronutrient supplements.
– Women’s nutrient needs increase
• One of the most important modifiers of pregnancy weight
gain and its impact on a mother’s and her baby’s health is
a woman’s weight at the start of pregnancy.
• Pre pregnancy weight is best measured by body mass
index (BMI).
BMI=
𝑤 𝑖𝑛 𝑘𝑔
(ℎ𝑡 𝑖𝑛 𝑚)2
•
PHN lecture notes 11

12. Weight gain during pregnancy
• Pregnancy is associated with weight gain
• Weight gain during pregnancy is mostly due to
– maternal reproductive tissues,
– fluid, blood, and maternal stores, which mostly
comprise body fat.
• These fat stores are an energy reserve during
pregnancy and lactation.
– Less than half of the weight gained is attributed
to the fetus, placenta and amniotic fluid.
• About 12kg weight gain is expected

13. Cont.…
• The acceptable weight gain during pregnancy is 8-
12kg
• The recommended weight gain is based on the
preconception BMI
– Higher 12kg and above is for those whose BMI is below
18.5kg/m2
– While the lower 8Kg is for those who are obese and
overweight.
• For good health of baby and mother, there should be
acceptable weight gain.

14. Recommendation weight gain
Pre pregnancy BMI Recommended weight
gain
<18.5 kg/m2
Underweight
12.5-18.5 kg
18.5-24.9kg/m2
Normal
11.5-16 kg
25-29.9kg/m2
Overweight
7-11.5 kg
>30kg/m2
Obese
5-7 kg

15. Excess Weight gain
• Increased pre-pregnancy weight and weight gain
during pregnancy adversely increases:
– Gestational diabetes;
– Preterm birth;
– Postdates;
– Operative delivery;
– Hypertension;
– Infections;
– Clotting disorders.
PHN lecture notes 15

16. Maternal physiological adaptation and fetal
nutrition
• When maternal nutrient intake fluctuates, it buffers
fetal nutrient supply
• In extreme cases of poor maternal nutrition(famine),
maternal adaption is insufficient to meet fetal nutrient
supply
• Under such condition fetal nutrient supply is restricted
• The gestational stage at which fetal nutrient supply is
comprised and that plausibly related to sequence of
organ and tissue development demarcates risk of
Chronic diseases

17. Consequences of Maternal Malnutrition
• Increased risk of maternal complications, infection
Anemia, Lethargy and weakness
• Consequences for fetal and infant health
– Increased risk of fetal, neonatal, and infant death
– Low birth weight,
– prematurity
– Birth defects, Cretinism, Brain damage
– Increased risk of infection
– Intrauterine growth Retardation (IUGR)

18. Low birth weight
• Birth weight of baby less than 2500gram
• Normal birth weight is 2.5 to 4 kg
• Consequence of LBW:
– Increased risk of infant and perinatal morbidity and
mortality
– Risk of growth faltering
– Reduced mental and working capacity
– Risk of adult hood chronic disease
– Poor Neurodevelopmental Outcomes

19. Nutritional programing
• It is the process through which variation in the
quality or quantity of nutrients consumed during
pregnancy exerts permanent effects upon the
developing fetus.
• It is important risk factor for non communicable
diseases of adulthood, including
– coronary heart disease and
– other disorders related to insulin resistance.
• Early Exposure determine later fate
• Thrifty phenotype hypothesis

20. Thrifty phenotype hypothesis
• Well known theory on impact of early
exposure on adulthood health.
• The concept of foetal nutrition
programming
• Says that reduced fetal growth is associated
with a number of chronic conditions later in
life
– Due to intrauterine fetal adaptation in
environment of limited supply of nutrients

21. FOOD
CATCH-UP
GROWTH
BP
Asymmetric Growth Restriction in Utero
Maternal Protein Deficiency
Impaired Kidney
Development
# Nephrons
(permanent)
“The Thrifty
Phenotype”
BODY
MASS
#
Nephrons

22. The Barker Hypothesis
Adverse intrauterine events
permanently “program” postnatal
structure/function/homeostasis
Fetal Origins of Adult Disease
* Better chance of fetal survival
* Increased risk of adult disease
“Adapted Birth Phenotype”

23. Cont…
• Early metabolic adaptation help survival of
organism by selecting appropriate
trajectory of growth
– Low birth weight
– IUGR
• These children are increased risk of
– Coronary Heart disease,
– Stroke
– Diabetes and hypertension

24. Cont…
• Individuals with thrifty phenotype will have small
body size, REDUCED METABOLIC CAPACITY and
behavioral activity
– Adapted to food shortage environment
• Later in life when exposed to excess of food (rich)
the adapted metabolic rate will not accommodate
the excess nutrient supply.
– Makes prone to type II DM, obesity and others

25. Energy Balance and body composition
• Energy balance is achieved when the kilocalories
consumed equal with the kilocalories expended

26. Positive Energy Balance
26
Energy
Expended
Energy
Intake
>

27. Negative Energy Balance
27
Energy
Intake
Energy
Expended
<

28. Energy Requirement
• Definition: The amount of energy intake from
food that replaces energy expenditure compatible
with normal health and allows an individual to be
involved in economically necessary and socially
desirable activities
• That promote long term health
• Include infant growth, and requirement for
pregnancy and lactation
 should be estimated based on Energy expenditure and
Not Based on Energy Intake
Energy Requirement= Energy Expenditure
28

29. Cont….
• Kilocalories come from foods and beverages
– Bomb calorimeter used is an instrument that measures
the heat energy released when foods are burned.
– Direct calorimetry measures the heat energy
released.
– Indirect calorimetry measures the amount of oxygen
consumed and carbon dioxide expelled
– Doubly labeled water
◦ Gold standard
◦ Measures energy expenditure over 7-14 days

30. Energy Out: The Calories of
the Body Expends
• One kcal is defined as the energy needed to rise
the temperature of water by 1 centigrade
• Energy expenditure includes basal metabolic
activities, physical activity, thermic effect of food
and adaptive thermogenesis.
• These energy requirements differ from person to
person and are affected by age, gender, weight,
and height

31. ◦ Physical activity
 Most variable and changeable
 Voluntary
 It can be significant in weight loss and weight
gain.
 Duration, frequency and intensity influence
energy expenditure.

32.  Estimating energy requirements is affected by
many factors.
◦ Gender – men generally have a higher BMR
◦ Growth – BMR is high in people who are
growing
◦ Age – BMR declines as lean body mass
decreases
◦ Physical activity – Activities are clustered by
intensity and vary considerably
◦ Body composition and body size – taller people
have more surface area and heavier people
have higher BMRs

33. What Is Body Composition?
• The ratio of fat tissue to lean body mass (muscle,
bone, and organs)
–Usually expressed as percentage body fat
–Important for measuring health risks associated
with too much body fat

34. Most Body Fat Is Stored in Adipose
Tissue
• Two types of fat make up total body fat
– Essential fat
• Found in bone marrow, heart, lungs, liver, spleen,
kidneys, intestines, muscles, and central nervous
system
• Women have 4 times more essential fat than men
– Stored fat
• Found in adipose tissue
• Subcutaneous fat – located under the skin
• Visceral fat – stored around the organs in the
abdominal area

35. Most Body Fat Is Stored in Adipose
Tissue
 In negative energy balance, fatty acids are
released from adipose cells
◦ Used as fuel and cells shrink
 In positive energy balance, fat accumulates
and adipose cells expand
 Brown adipose tissue (BAT) is another type of
fat tissue made up of specialized fat cells
◦ Contain more mitochondria and rich in blood
◦ Function is to generate heat
◦ Found primarily in infants

36. Body Fat Distribution Affects Health
 Storing excess fat around the waist versus the hips and
thighs increases risk of heart disease, diabetes, and
hypertension
 Central obesity (android obesity) ====apple shaped
obesity - from storing too much visceral fat in the
abdomen
 Gynoid obesity =Pear shaped obesity-from excess fat
around the thighs and buttocks
 Visceral fat releases fatty acids which travel to the liver
causing insulin resistance, increased LDL, decreased
HDL, and increased cholesterol

37. Health Risks Associated with Body Weight and
Body Composition
 Being underweight increases health risks
◦ Symptomatic of malnutrition, substance abuse, or disease
◦ Higher risk of anemia, osteoporosis and bone fractures,
heart irregularities, and amenorrhea
◦ Correlated with depression and anxiety, inability to fight
infection, trouble regulating body temperature, decreased
muscle strength, and risk of premature death
◦ May be unintentional and due to malabsorption associated
with diseases such as cancer, inflammatory bowel disease,
or celiac disease

38. Health Risks Associated with Body Weight and
Body Composition
• Being overweight increases health risks
– Overweight and obesity associated with increased risk
of heart disease, hypertension, stroke, hyperlipidemia,
gallstones, sleep apnea, and reproductive problems
– Increases risk of certain cancers including colon,
breast, endometrial, and gallbladder cancer
– More than 80% of people with type 2 diabetes are
overweight
– Metabolic syndrome is associated with central obesity