Nutrition and the Physiology of Malnutrition Lia Fernald, Ph.D., M.B.A. Human Biology Lecture May 14, 2002.

Nutrition and the Physiology of Malnutrition

Lia Fernald, Ph.D., M.B.A.

Human Biology Lecture

May 14, 2002

Male, 17, Oakland, weekly dietMon Tues Wed Sat

Sausage, egg cheese burrito (McD)

Nothing Frosted Flakes Hot link with mustard, ketchup, Coke

Personal size pepperoni pizza

Double cheese burger, fries, Coke (BK)

Pepperoni pizza (PH) and french fries

Nation’s cheeseburger, large fries, Coke

Burrito from vending machine, Lays

Banana nut muffin and carton of milk

2 ham & cheese sandwiches and can of soda

2 hot dogs, blueberry muffin

Spaghetti, fried chicken, fruit punch

Small round pizza

Baked pork chops, mac & cheese, Pepsi

Fries, BBQ bacon cheese burger (McD)

3,045 (38%)

2,400 (41%)

2,739 (33%)

3,163 (36%)

B

L

S

D

Overweight 9th graders in the Bay Area

“Overweight” defined as more than 25% body fat for boys and more than 32% for girls. Less than 1% of students are out of shape because they are too thin.

0%

5%

10%

15%

20%

25%

30%

35%

% overweight

Alameda

San Mateo

Napa

Solano

Sonoma

Santa Clara

Contra Costa

Marin

San Francisco

Today’s Class• Overview of Nutritional Requirements• Definition of Malnutrition• Causes and correlates of Malnutrition• Measurement and Types of Malnutrition • Severe Malnutrition• Mild/Moderate Malnutrition (Underweight

and Stunting)• Specific Nutritional Deficiencies (Iodine and

Iron)

Nutritional requirements

Macro v. micro nutrients• Macro-nutrients

– Protein (amino acids)– Energy (carbohydrates)– Fat (fatty acids)

• Micro-nutrients– Water soluble vitamins (assist in energy-release of

carbohydrates and red blood cell formation)– Fat soluble vitamins (development & metabolism)– Minerals

Macro-nutrients• Energy

– Necessary for all bodily function

• Protein– Necessary for structural development (muscle

and bone)

• Fat– Necessary for cell membrane and skin cell

development

Dietary Reference Intakes

Macronutrient F (19-30 y.o.) M (19-30 y.o.)

Energy (Kcal)

Protein (g)

1940 – 2200

36 – 46

2550 – 2900

44 – 60

Fat 15 – 33% 15 – 33%

Water soluble vitamins• Thiamin B

– nervous system function, enzymatic energy release of carbohydrates (beef, pork, liver, legumes, breads)

• Riboflavin B2– Participants in enzymatic energy release of carbs, fat & protein (milk,

dairy, dark green vegetables, yogurt)• Niacin

– Participates in enzymatic energy release of energy nutrients (beef, pork, liver, breads, nuts)

• Folate– Red blood cell formation, new cell division (veg, seeds)

• Vitamin B12 (Cobalamin)– Red blood cell formation, nervous system maintainance (animal prod)

• Pantothenic Acid• Biotin (Vitamin H, CoEnzyme R)• Vitamin B6 (Pyridoxine)• Vitamin C

Fat soluble vitamins• Vitamin A

– Essential to vision, fetal development, immune response– Found in dairy products, fish liver oils; as B-carotene found in

many plants (e.g. carrots, mango)

• Vitamin D – Bone formation, calcium metabolism and absorption– Found in sunlight, egg yolk, dairy products and fish liver oil

• Vitamin E– Cell membrane construction and maintenance– In fats and oils, green leafy vegetables, poultry, fish

• Vitamin K– Blood clotting, protein synthesis– In green leafy vegetables, liver, cabbage

MineralsMajor “Bone” Minerals Trace Minerals

Calcium (bones) Iodine (thyroid function)Phosphorus (DNA) Iron (hemoglobin) Magnesium (bones) Zinc (enzyme, hormone)Sodium (nerve impulse) Copper (abs. of iron)Chloride (fluid balance) Flouride (bone & teeth)Potassium (prot. syn) Chromium (energy rel.)Sulfur (some a.a.’s) Molybdenum (enzymes)

Manganese (enzymes)Selenium (antioxidant)Cobalt (part of B12)

Summary: Nutritional requirements

• In order to live and function, humans need macro- and micro- nutrients;

• Macro-nutrients are fat, protein and carbohydrates;

• Micro-nutrients are water-soluble vitamins, fat-soluble vitamins, and minerals (bone and trace); the most critical micro-nutrients are iron, iodine, zinc, vitamin A and vitamin D.

Today’s Class• Overview of Nutritional Requirements• Definition of Malnutrition• Causes and correlates of Malnutrition• Measurement and Types of Malnutrition• Severe Malnutrition• Mild/Moderate Malnutrition (Underweight


Iron)

What is malnutrition?World Health Organization definition:

The term is used to refer to a number of diseases, each with a specific cause related to one or more nutrients (for example, protein, iodine or iron) and each characterized by cellular imbalance between the supply of nutrients and energy on the one hand, and the body's demand for them to ensure growth, maintenance, and specific functions, on the other.

Countries at risk of malnutrition

Geneva Declaration1924: Declaration of the Rights of the Child (also known as the Declaration of Geneva).

• Adopted after World War I by the League of Nations through the efforts of British child rights pioneer

• Marks the beginning of the international child rights movement and is also the first international affirmation of the right to nutrition.

• Affirms that "the child must be given the means needed for its normal development, both materially and spiritually" and states that "the hungry child should be fed."

Death from malnutrition

Source: WHO, based on C.J.L. Murray and A.D. Lopez, The Global Burden of Disease, Harvard University Press, Cambridge (USA) 1996 and American Journal of Public Health 1993-83.

*

*

*

*

* At least 70% of childhood diseases are related with one of these conditions

*

Summary: Definition of malnutrition

• Malnutrition is having the inappropriate level of a micro- or macronutrient;

• In some cases (i.e. the US), malnutrition can be associated with being grossly overweight;

• In most of the world, malnutrition is defined as a LACK of nutrients;

• Malnutrition contributes to over 50% of deaths in children in the world.

Today’s Class• Overview of Nutritional Requirements• Definition of Malnutrition• Causes and correlates of Malnutrition• Measurement and Types of Malnutrition• Severe Malnutrition• Mild/Moderate Malnutrition (Underweight


Iron)

Child malnutritiondeath and disability

Inadequate DiseaseDiet

Insufficientaccess to food

Inadequatematernal and

child care

Poor water/ sanitationinadequate health

services

Causes of malnutrition

BabyLow Birth

Weight

ChildStunted

AdolescentStunted

WomanMalnourished

Pregnancy Low Weight Gain

ElderlyMalnourished

Highermortality rate

Impairedmental

developmentIncreased risk of

adult chronic disease

Untimely/inadequateweaning

FrequentInfections

Inadequatecatch upgrowth

Inadequatefood, health

& care

Reducedmental

capacity


& care

Reducedmental

capacity

Inadequatefetal

nutrition

Inadequatefood, health& care


& care

Highermaternalmortality

Reducedcapacityto care

for baby

Start here

Correlate: Unsafe Water

Source for photos: Overseas Aid: www.nat.uca.org.au, Statistics, UNICEF State of the World’s Children 2000

11% urban and 38% rural households do not have access to safe water

http://www.nat.uca.org.au/

Correlate: Inadequate Sanitation


21% urban and 75% rural households do not have access to adequate sanitation


Correlate: Poor Education


25% of girls and 19% of boys do not enter primary school;

54% of girls and 45% of boys do not enter secondary school


Correlate: Poverty

28% of the population lives at below $1 per day

Average GNP per capita is $1299(compared with $29,080 in USA)



Correlate: Poor Stimulation


39% of females and 21% of males over the age of 15 cannot read or write

199 radios per 1000 population; 154 TV’s per 1000 population


Correlate: Poor Public Health

About 30% of 1-year olds are not fully immunized for TB, DPT (Diptheria, Pertussis, and Tetanus), polio and measles



Correlate: No Breastfeeding

Source: Children’s Hospital Islamabad

Babies are twins (boy and girl)

Mother was told that she wouldn’t have enoughbreast milk for both, so should bottle feed girl . . . girl died the day after this photo was taken

56% babies in developing countries are not breastfed from 0-3 months

Summary: Causes/correlates• Malnutrition rarely exists in isolation, and many

other factors contribute to its detrimental impact;– Poor physical resources, and overcrowded homes– Poor sanitation and water supply– Low income– Parents with little education– Minimal interaction/stimulation in the home

• Malnutrition has repercussions throughout the life cycle and is thus multi-generational (diagram with lots of arrows)

Today’s Class• Overview of Nutritional Requirements• Definition of Malnutrition• Correlates of Malnutrition• Measurement and Types of Malnutrition• Severe Malnutrition• Mild/Moderate Malnutrition (Underweight


Iron)

Types of malnutrition• Severe Protein-Energy Malnutrition (>3 S.D.)

– Kwashiorkor (low protein)– Marasmus (low calories)

• Mild/moderate undernutrition (>2 S.D.)– Stunting– Underweight– Wasting

• Micro-nutrient deficiency– Iodine– Iron– Vitamin A– Vitamin D

Measurement of Malnutrition• STUNTING: Height for age – height

compared to a reference population of the same age.

= represents long term growth retardation

• UNDERWEIGHT: Weight for age – weight compared to age in a reference population

• WASTING: Weight for height – weight compared to a reference population of the same height.

Growth Curves (0-3 years)

Weight

Length/Height

Age

http://www.keepkidshealthy.com/growthcharts/girlsbirth.gif

http://www.keepkidshealthy.com/growthcharts/boysbirth.gif

http://www.keepkidshealthy.com/growthcharts/boysbirth.gif

Summary: Measurement• There are several types of malnutrition,

micro- and macro-malnutrition;

• Measurement of severe malnutrition (>3 S.D.) and micro-nutrient deficiency usually occurs due to presence of critical signs (to be discussed);

• Measurement of mild/moderate malnutrition (>2 S.D.) occurs with growth charts.



Iron)

Severe malnutrition % <5 y.o.

Developing Countries 12%

Least Developed Countries 13%(India 21%, Bangladesh 21%, Cambodia 18%)Data for 1992-98, UNICEF State of the World’s Children 2000

0%2%4%6%8%

10%12%14%16%18%20%

%

South Asia

Sub-Saharan Africa

Middle East andNorth Africa

CEE/CIS & BalticStates

Latin America &Caribbean

Severe PEM: Real NumbersExample: India• 21% of all children under 5• # children under 5 is 115,615,000• 24M children severely malnourished (Bigger than

population of Texas 20M)Example: All developing countries• Total # <5 in developing countries: 536,105,000

and 12% of that is:• 64M children under 5y.o. severely malnourished

(California & New York & Florida)Example: World (total number is 603,449,000)11% = 66M (France or England)

Kwashiorkor

Swollen belly

Pellagra

Decreasedmusclemass

Sparsehair

Infection

Apathy

Kwashiorkor (low protein)• Decreased muscle mass (failure to gain weight and of

linear growth) • Swollen belly (edema and lipid build-up around the liver) • Changes in skin pigment (pellagra); may lose pigment

where the skin has peeled away (desquamated) and the skin may darken where it has been irritated or traumatized

• Hair lightens and thins, or becomes reddish and brittle. • Increased infections and increased severity of normally

mild infection, diarrhea• Apathy, lethargy, irritability

Death does not occur from actual starvation but from secondary infection

Kwashiorkor – mechanisms• Occurs in reaction to emergency situations

(famine)

• Kwashiorkor more likely in areas where cassava, yam, plantain, rice and maize are staples, not wheat

• Increased carbohydrate intake with decreased protein intake eventually leads to edema (water) and fatty liver

Marasmus (low calories)

Ravenouslyhungry

Gross weightloss & no fat

Marasmus• Deficit in calories – “marasmus” comes

from Greek origin of word “to waste”• Gross weight loss• Hyper-alert and ravenously hungry• Children have no subcutaneous fat or

muscle

eventually starve to death (immediate cause often is pneumonia)

Marasmus – mechanism • Energy intake is insufficient for body’s

requirements – body must draw on own stores• Liver glycogen exhausted in a few hours –

skeletal muscle protein used via gluconeogenesis to maintain adequate plasma glucose

• When near starvation is prolonged, fatty acids are incompletely oxidized to ketone bodies, which can be used by brain and other organs for energy

• High cortisol and growth hormone levels

Mechanism is same as anorexia

• Mental development– Lower IQ levels– Poorer school performance

• Behaviors of recovered severely malnourished children

– shy, isolated, withdrawn – decreased attention span– immature, emotionally unstable– fewer peer relationships/reduced social skills– played less/stayed nearer to mothers

Severe Malnutrition: Consequences

Summary: Severe malnutrition• Severe malnutrition is defined as > 3 s.d.

away from median reference standards;

• 66M children under the age of 5 are severely malnourished (64M of these in developing countries);

• Key types of severe malnutrition are kwashiorkor (low protein) and marasmus (low calories);

• Severe malnutrition results in severe deficits for children



Iron)

Stunting – Height for Age• Height for age reflects pre- and post- natal

linear growth

• “Stunting” refers to shortness that is not genetic, but due to poor health or nutrition

• Most standard definition < 2 S.D.

• Stunting is good cumulative measure of “well-being” for populations of children (because not affected by weight recovery)

Stunting

These girls are:

From same school and the same neighborhood

Both have the same birthday

Stunting % <5 y.o.

Developing Countries 39%Least Developed Countries 47%

Data for 1992-98, UNICEF State of the World’s Children 2000(India 52%, Bangladesh 55%, Cambodia 56%)

0%

10%

20%

30%

40%

50%

60%South Asia

Sub-SaharanAfrica

Middle Eastand NorthAfrica

Latin America& Caribbean

CEE/CIS &Baltic States

Stunting: Real NumbersIndia where 52% of all children under 5 (total <5 is

115,615,000) are stunted60M children in India are stunted (as many

people live in the MidWest)

Example all developing countries, where 39% of all children under 5 (536,105,000)

209M children in dev world

In world, the total # of children <5 is 603,449,000 and 37% of that is

223M children in world (US popn 272M US minus California and Texas)

Stunting: Causes• Poor nutrition plays major role• Role of environment: improvements in

average height shown by populations over last century (impact of genetic influence subsumed by level of socio-economic development)

In 1833, British children were as tall as children today from India and Guatemala

All immigrant populations have same height after 3 generations in US

Stunting: Timing• Age of onset varies, but usually in first 2-3

years of life• First few months, infants in developing

countries grow just as quickly as children in reference populations– Growth retardation starts from 2-6 month of life

(often associated with weaning)– Infants at risk during this time because of high

nutritional requirements and high rates of infections (breast fed infants often protected)

Stunting: Consequences• Cross-sectional associations – Low height

for age associated with:– Reduced cognitive development– Poor motor skills– Poor neuro-sensory integration– Quiet, reserved, withdrawn, timid, passive– Difficulty making decisions– Decreased involvement with environment,

toys, tasks– Less able to deal with stressor such as hunger

or parasites

poornutrition

poor mentaldevelopment &

behavior

alterations indevelopment

of CNS

“functionalisolation”

emotional reactivity,impaired

stress response

Hypothesized Mechanisms

Summary: Mild/moderate maln.• Stunting refers to growth retardation (>2

S.D.) secondary to malnutrition;

• Almost 40% (223M) of children <5 in the developing world are stunted;

• Children are most at risk for stunting in the first 2-3 years of life;

• Stunting is associated with poor mental development and altered behavior.


and Stunting)• Specific Nutritional Deficiencies (Iodine,

Iron, Vitamin A, Vitamin D)

Specific Nutritional Deficiencies• Iodine Deficiency

• Iron Deficiency

• Vitamin A

• Vitamin D

Iodine deficiency - thyroid

“Simple goiter is the easiest of all known diseases to prevent . . . It may be excluded from the list of human diseases as soon associety determines to make the effort” David Marine 1923

Iodine Deficiency Disorders

Source: State of the World’s Children, 1998

Causes of Iodine Deficiency• Mountainous areas at risk (soils leached by

high rainfall, melting snow, flooding)

• Culturally induced behavioral change– Tasmanian Aboriginals migrated every season

until European invasion, became sedentary and had incidence of thyroid problems

Iodine Deficiency: Severe• Goiter: most commonly recognized

consequence (enlarged thyroid)– Occurs when thyroid gland is unable to meet

the metabolic demands of the body through sufficient hormone production – thyroid compensates by enlarging (works in short term)

• Cretenism: proximal pyramidal signs, intellectual impairment, primitive reflexes– Only occurs with severe fetal iodine deficiency

Iodine Deficiency: Moderate• Studies comparing 2 Villages

– Consistent results: meta-analysis showed 13.5 IQ point difference between groups

• Intervention Studies– Prenatal supplementation (esp. 1st trimester):

clear impact – prevents cretenism, and affects mental development in children

– Childhood supplementation: many mediocre studies, but positive impact

Source:UN ACC-SCN-IFPRI - 4th Report on World Nutrition Situation

Iron deficiency - anemia

%

Source: UN-ACC-SCN-IFPRI-4 Report on World Nutrition Situation

0

10

20

30

40

50

60

70

80

% pregnant women

South CentralAsia

West Africa

East Africa

Eastern Europe

Oceania

Iron Deficiency• Iron is critical for body:

– Carries oxygen to tissues from lungs– Transports electrons within cells– Integral part of important enzyme reactions

• Anemia is caused most commonly by iron deficiency (anemia is found in 40-60% of women and children in developing countries)

Iron Deficiency Consequences• Iron deficiency results in:

– Decreased work capacity and work productivity– Permanently impaired development

• Psychomotor development of anemic children will be reduced by 5-10 IQ points

– Increased morbidity and mortality from infections

– Decreased growth

Vitamin A Deficiency

• Vitamin A is important because it is essential to vision, fetal development, immune response

• 250 million children of pre-school age lack sufficient Vitamin A in their diet.

• 350,000 become blind each year, and half of them die within a year of becoming blind….

Vitamin A Deficiency• Associated with blindness and increased severity of infections such as measles and diarrhoeal disease

• WHO estimates that 2.8 million children under 5 years old have signs of clinical xerophthalmia (childhood blindness)

• WHO estimates that 14 million pre-school children already have some eye damage from Vitamin A deficiency

Vitamin D Deficiency: Rickets

http://www.spoilheap.co.uk/rickets.htm

Summary: Micronutrient deficiency• Iodine is critical for thyroid function –

deficiency results in cretinism & goiter

• Iron is critical for blood and muscles – deficiency results in anemia

• Vitamin A is critical for visual development – deficiency results in blindness

• Vitamin D is critical for bone development – deficiency results in rickets

From UNICEF, State of the World’s Children: Adapted from Stuart Gillespie, John Mason and Reynaldo Martorell, How nutrition improves, ACC/SCN, Geneva 1996.

Where do we go from here?

Improved childnutrition

Increasedproductivity

Enhanced humancapital

Povertyreduction Economic growth

Social sectorinvestments

Nutrition and the Physiology of Malnutrition Lia Fernald, Ph.D., M.B.A. Human Biology Lecture May 14, 2002.

Documents

iron slide

cabbage slide

skin cell development

fish vitamin

fat soluble vitamins

synchromium energy

s d slide

bone fat necessary