EXAM
Lisa
ch3.pptxMalnutrition
Chapter 3
Dr. WJ Mueller
Malnutrition:
“Overconsumption or under-consumption of any essential nutrient.”
Four Types of malnutrition
Over-nutrition
Secondary malnutrition
Dietary deficiency or micronutrient malnutrition
Protein-calorie malnutrition
Overnutrition
Over-nutrition
Consuming too many calories
The most common problem in high-income countries and high-income people in low-income countries
Diet high in:
Calories
Saturated fat
Salt
Sugar
Over-nutrition (cont.)
Related illnesses include:
Obesity
Diabetes
Hypertension
Atherosclerosis
Secondary Malnutrition
Secondary Malnutrition
Person has a condition or illness that prevents proper digestion or absorption of food
Causes include:
Diarrhea
Respiratory illnesses
Measles
Intestinal parasites
Secondary Malnutrition (cont.)
Mechanisms include:
Loss of appetite (anorexia)
Alternation of normal metabolism (illness)
Prevent nutrient absorption (diarrhea)
Parasites take nutrients
Solutions
Sanitation (garbage disposal, human waste)
Clean water
Solutions
People suffering from undernutrition have the problem exacerbated by secondary malnutrition
Undernutrition and secondary malnutrition are often lumped together
Dietary Deficiency or Micronutrient Malnutrition
Dietary Deficiency or Micronutrient Malnutrition Defined:
Diet lacking in one or more essential micronutrients (vitamins/minerals)
The most important ones:
Vitamin A (carotene)
Iodine
Iron
Iron Deficiency (dietary iron)
Anemia
Lack of energy (less work)
Less able to learn/think
Greater risk of infection
Increased death during pregnancy & child birth
40% of people in developing countries suffer from it
Sources
Meats (all kinds)
Fortified foods (cereal, oatmeal, etc.)
Beans
Spinach
Raisins
Whole-wheat bread
Other Nutrient Deficiencies
Zinc
B vitamins
Vitamin C
Vitamin D
Solution
Inexpensive (compared to undernutrition)
Estimated $3.00/year/person for vitamin A, Iron & iodine (1994)
Calorie and Protein Malnutrition (PCM)
Easy to solve: Have more food for people to eat
Of course it is more difficult than that
Difficulty
Balanced diet needed to get the right proteins and adequate calories
Body gets energy from food (calories)
Carbohydrates (sugar & starch; 4 calories/gram)
Protein (4 cal/g)
Fats (oil; 9 cal/g)
Know these numbers
What calories are used for?
Involuntary functions
Breathing
Blood circulation
Digestion
Body muscle
Body temperature
Physical activity
Mental activity
Fighting disease
Growth
Proteins provide Amino Acids
Body building blocks (muscle, hair, membranes
Blood (carries oxygen to and CO2 from all parts of the body)
Membranes (nutrient movement into and out of cells)
Antibodies (fight diseases)
Enzymes (digestion)
Proteins (cont.)
20 amino acids (AA’s) required by humans
9 are “essential AA’s”
They cannot be synthesized by the body from other AA’s
All can be obtained from eggs, milk and meat
Most plants provide 17 of 20
Proteins (cont.)
If you are a vegetarian, you must especially worry about:
Methionine
Lysine
Cysteine
Certain plants have more of these than others
Beans, whole wheat, peanuts, corn
Proteins (cont.)
Proteins are made of AA’s
The order of the AA’s determine the type of protein
If one or more are lacking certain AA’s in the diet, then certain proteins cannot be made
Quick Review
The origin of all energy is the sun
Photosynthesis
Energy from sun used to produce sugars
Sugars easily converted to starch
More energy required to convert sugars to fats
More processes involved in making protein
Proteins contain a lot of nitrogen
Nitrogen fixation by various mechanisms allows it to be useable by living things
Remember 78% of air is Nitrogen (N2), but that is not available for use
Proteins
Protein is more expensive than other forms of calories
Hamburger is more expensive than rice
The mean is the average requirement
The median means half are above and half are below
The standard deviation (SD) shows how much variation exists from the mean
How much of a nutrient is enough?
It is not the same for every person
A normal distribution represents a group of people based on how much of a specific nutrient each needs
Blue is the range of one SD from the mean
(68% of people fall within that range)
Pink is two SD’s from the mean
Orange three SD’s from the mean
Does three SD’s from the mean cover every person?
Proportion of individuals
Increasing intake of a given nutrient, increases the percentage of people who consume adequate amounts
The RDA (recommended daily allowance) for a nutrient is set at 2 standard deviations above the mean
a. This will cover the requirements of 97.5% of the people in this group
Cut-off points are based on the median
Reference groups
Provide a standard against which an individual’s nutritional status can be judged
A person has a nutritional problem if they are below a certain cut-off point (or above)
Percentile
a. Measures the percentage of the reference group that is below this point
b. Height at 30th percentile means that 30% of the group is shorter than this individual
c. Median is the 50th percentile (of course)
Median
50%
50%
Median
50%
50%
