Transcript Incomplete proteins

Chapter 14
Nutrients That Promote Growth
& Regulate Body Functions
(Proteins, Vitamins, Minerals, and Water)
©2015 Cengage Learning.
Growth
• Growth is the result of:
– An increase in the number of cells
– An increase in the size of cells
Proteins
• Yield amino acids
• Are either complete or incomplete
– Complete proteins yield all the essential amino
acids.
– Incomplete proteins are lacking
one or more essential amino acids.
Proteins
• Incomplete proteins can be combined to
provide all of the essential amino acids:
– Supplementary proteins = incomplete
protein plus a small amount of complete
protein
– Complementary proteins = two or more
incomplete proteins, when combined, form a
complete protein
Proteins as Regulators
• Proteins are involved in a
variety of regulatory
processes:
– Energy metabolism
– Fluid distribution
– Hormone production
How Much Protein Is Needed?
Infants:
0 to 6 mo.
7 to 12 mo.
Protein Needed
9.1 g/day
11.0 g/day
Children:
1 to 3 yr.
4 to 8 yr.
Males: over 18 yr.
Females: over 18 yr.
13.0 g/day
19.0 g/day
56.0 g/day
46.0 g/day
Protein Requirements Are Easy to
Meet
Food
Protein
2 cups of milk
16.0 grams
1 slice whole wheat bread
2.7 grams
1 ounce meat
7.0 grams
1 slice provolone cheese
7.0 grams
1 egg
5.5 grams
3 wheat crackers
.5 grams
2 oz. cooked pasta
7.0 grams
TOTAL = 45.7 grams
©2012 Cengage Learning.
All Rights Reserved.
Children on Vegetarian Diets
• Vegan—nuts, seeds, legumes, fruits and
vegetables
• Lacto-vegetarian—in addition, dairy products
• Ovo-vegetarian—in addition, egg products
• Lacto-ovo vegetarian—in addition, both dairy
and egg products
Can all of a child’s protein, iron and
calcium needs be met if he or she follows
a vegetarian diet?
Vitamins
• Vitamins are needed in small amounts
(Table 14-3).
• Large doses of some vitamins can be toxic.
• Vitamins are classified as:
– Water soluble
– Fat soluble
Vitamins
• Water soluble vitamins:
– are not stored in the body and must be consumed
daily
– include Vitamin C, thiamin, niacin, riboflavin, vitamin
B6 and B12, pantothenic acid, folacin, and biotin.
• Fat soluble vitamins:
– are stored in the body and can be toxic if consumed
in large supplement doses
– include vitamins A, D, E, and K
Vitamins
• Vitamins support growth
– DNA and RNA production
– Cell division
– Bone and blood formation
• Vitamins are involved in regulating body
functions
– Bone development
– Energy metabolism
– Neuromuscular function
Should Children Take Vitamin
Supplements?
• Families should always check first with the
child’s physician.
• Vitamin supplements provide small amounts of
many vitamins, but not always in the amounts
required. For example, only 10 percent of a
child’s calcium requirement may be met with a
vitamin supplement. This may give parents false
assurance that children’s intake is adequate.
Should Children Take Vitamin
Supplements?
• Vitamin supplements may be helpful for some
children who are picky eaters.
• Essential nutrients, such as protein and fiber,
accompany the vitamins found in food sources
but are absent in supplements.
Minerals
• Provide no energy
• Are inorganic substances that are
only needed in small amounts
• Are essential for:
– building of body tissues (e.g., bone, teeth, blood)
– regulating body functions (e.g., energy metabolism,
neuromuscular function)
Bone and Tooth Formation
• What minerals are required for healthy
bone and tooth formation?
– Calcium
– Phosphorus
– Fluoride
• What food sources supply each of these
minerals?
Calcium
• Most children today do not get enough
calcium in their diet.
– What factors may be contributing
to this change?
– What sources other than milk
supply calcium?
Calcium
• Factors that increase the absorption of dietary
calcium:
5 adequate vitamin C and D
5 increased need
• Factors that decrease the absorption of dietary
calcium:
▼ large
dose
high dietary fiber
▼ high intake of protein
▼
Iron
• Iron plays a critical role in the formation of
blood cells.
• Inadequate iron can contribute to irondeficiency anemia.
• Dietary iron is not well-absorbed by the
body. Iron absorption is improved when
vitamin C is present in a meal.
Building Blood
• Every red blood cell in the body contains
iron in its hemoglobin -- the pigment that
carries oxygen to the tissues from the
lungs.
• Red blood cells bring oxygen to body
tissues.
©2012 Cengage Learning.
All Rights Reserved.
Iron-deficiency Anemia
• Anemia is a condition in which the body
does not have enough healthy red blood
cells.
• There are many types of anemia.
• Iron deficiency anemia is a decrease in the
number of red blood cells in the blood due
to a lack of iron.
©2012 Cengage Learning.
All Rights Reserved.
Iron-deficiency Anemia
• Most prevalent nutritional problem in children
in U.S.
• Twice as likely to occur in poor families
• Children may have trouble concentrating,
which may affect brain development
• Diets need sufficient amounts of iron to
prevent it
• Infants need vitamin supplements
Causes of IDA
• insufficient iron in the diet
• poor absorption of iron by the body
• ongoing blood loss, most commonly from
menstruation or from gradual blood loss in
the intestinal tract
• periods of rapid growth
©2012 Cengage Learning.
All Rights Reserved.
Iron-deficiency Anemia
• Inadequate iron can contribute to irondeficiency anemia.
• Dietary iron is not well-absorbed by the
body.
• Including vitamin C in a meal improves the
absorption of iron.
©2012 Cengage Learning.
All Rights Reserved.
Symptoms
• fatigue and weakness
• pale skin and mucous membranes
• rapid heartbeat or a new heart murmur (detected
in an exam by your child's doctor)
• irritability
• decreased appetite
• dizziness or a feeling of being lightheaded
• Rarely, a person with IDA may experience pica,
©2012 Cengage Learning.
All Rights Reserved.
Diagnosis and Treatment
• Blood tests
• Diet changes alone usually aren't enough
to replenish depleted iron stores.
• Multivitamins with iron aren't adequate for
kids with IDA who have such low iron
stores, so a separate daily iron
supplement may be required.
©2012 Cengage Learning.
All Rights Reserved.
IDA is Preventable
• Infants younger than 1 year old should drink only
breast milk or an infant formula supplemented
with iron.
• Breastfed infants should receive iron-fortified
solid foods starting at about 6 months of age.
• Kids under 2 years old should have no more
than 24 ounces of cow's milk a day.
• Use Iron-fortified products such as cereal.
• A variety of foods can provide great sources of
iron.
©2012 Cengage Learning.
All Rights Reserved.
Water
• Water plays important roles in the body:
– Fluid replacement
– Temperature regulation
– Building body tissues
• A child’s need for water is
influenced by:
– Environmental temperature
– Body surface
– Activity
Case Study
• Mealtimes were frustrating for Akecheta's mother. Her
four-year-old son often refused to drink his milk and
begged for juice instead. He complained “that his
stomach hurt” and would cry until his mother gave in to
his requests. She was becoming extremely frustrated
and finally decided to take him to the local health clinic
for advice.
• After several visits and tests, the physician assistant
determined that Akecheta was lactose intolerant and
allergic to citrus fruits. Even small amounts of milk or
cheese seemed to upset his stomach and orange juice
caused him to break out in hives.
Questions for Case Study
1. What nutrients will Akecheta lack if these food
groups are eliminated from his diet?
2. Would you expect symptoms of a deficiency to
appear immediately or long term? Explain.
3. Suggest several foods that have the same
nutrient-strength and could be served in place
of citrus fruits and dairy products?
4. Should Akecheta be given nutrient
supplements to offset potential deficiencies?
Why or why not?