Transcript Lecture 4a powerpoint

The need for the Students’ Union to offer tutoring services has dropped off with
the recent introduction of free academic supports on campus for math, science,
and business (Math & Science Centre), as well as support for improving study
skills, time management, etc. (Academic Success Coaching).
•excellent academic supports available to students:
Math & Science Centre (free drop-in tutoring in introductory math, science, and
business courses Mondays – Thursdays 3-8pm in the Learning Commons)
Academic Success Coaching (free coaching in skills such as time management and
study skills Mondays – Fridays 9am-4pm, typically by appointment)
Writing Centre (free writing tutoring Mondays – Fridays 9am-4pm, typically by
appointment)
*new, coming soon- Tutor Database (connecting tutees directly with potential
tutors for hire)
•Any questions about the Writing Centre, Math & Science Centre, and Tutor
Database can be directed to Tammy Byrne, and questions about Academic Success
Coaching can be directed to Alyssa MacDonald.
Water and Minerals-Chapter 6
Metabolism-no readings
Energy Balance-Chapter 7
Nutrition throughout the
Lifespan-Chapters 11,12,13
Water
• Functions of water
– Occupies essentially every space within and
between body cells
– Involved in virtually every body function
– Largest single constituent of the human body,
averaging 60% of total body weight
– Provides shape and structure to cells
– Regulates body temperature
– Aids in the digestion and absorption of nutrients
Water—(cont.)
• Functions of water—(cont.)
– Transports nutrients and oxygen to cells
– Serves as a solvent for vitamins, minerals,
glucose, and amino acids
– Participates in metabolic reactions
– Eliminates waste products
– Is a major component of mucus and other
lubricating fluids
Water—(cont.)
• Water balance
– Total body water balance is tightly regulated
within ±0.2% of body weight.
– Sensation of thirst and the action of the hormone
vasopressin control our daily fluid balance.
o Water output
 Adults lose approximately 1750 to 3000
mL of water daily.
 If in water balance, water losses must be
replaced by consuming fluid in the form of
drinks and foods
Water—(cont.)
• Water intake
o Drinking water
o Other beverages
o Solid foods
Water—(cont.)
• Water recommendations
– Body cannot produce as much water as it
needs.
– For men ages 19 to older than 70 years,
the Adequate Intake (AI) is 3.7 L/day.
– For women of the same age, the AI is 2.7
L/day.
– Daily intakes below the AI may not be
harmful to healthy people.
Water—(cont.)
• Water recommendations—(cont.)
– Fluid intake is assumed to be adequate when
the color of urine produced is pale yellow.
– Elderly and children
o Drinking fluids should not be delayed until
the sensation of thirst occurs.
Water—(cont.)
• Water recommendations—(cont.)
– Increases in water loss
o Vomiting, diarrhea, and fever
o Thermal injuries, fistulas, uncontrolled
diabetes, hemorrhage, and certain renal
disorders
o Use of drainage tubes contributes to increased
water losses.
o Intake and output records are used to assess
adequacy of intake.
Water—(cont.)
• Alterations in intake
– Dehydration is characterized by
o Impaired mental function
o Impaired motor control
o Increased body temperature during exercise
o Increased resting heart rate when standing
or lying down
o Increased risk of life-threatening heat stroke
Water—(cont.)
• Alterations in intake—(cont.)
– A net water loss of as little as 1% of body weight
increases plasma osmolality.
– A loss of 20% can be life threatening.
• Hyponatremia
– At risk patients include infants; psychiatric patients
with excessive thirst; women who have undergone
surgery using a uterine distention medium; and
athletes in endurance events who drink too much
water, fail to replace lost sodium, or both.
Water—(cont.)
• Hyponatremia—(cont.)
– Symptoms
o Lung congestion, muscle weakness,
lethargy, and confusion
o Can progress to convulsions, prolonged
coma, and death
Minerals
Keys to Understanding Minerals
• Major minerals are present in the body in
amounts greater than 5 g.
• Calcium, phosphorus, magnesium, sulfur,
sodium, potassium, and chloride are major
minerals.
• Iron, iodine, zinc, selenium, copper,
manganese, fluoride, chromium, and
molybdenum are classified as minor or trace
minerals or minor or trace elements (present in
body in amounts less than 5 g (iron ~ 5 g).
• Both major and minor minerals are essential for
life.
Keys to Understanding Minerals—(cont.)
• General chemistry
– Minerals do not undergo digestion, nor are
they broken down or rearranged during
metabolism.
– Minerals are not destroyed by light, air, heat,
or acids during food preparation.
Keys to Understanding Minerals—(cont.)
• General functions
– Minerals function to provide structure to body
tissues and to regulate body processes.
• Mineral balance
– Maintained by
o Releasing minerals from storage for
redistribution
o Altering rate of absorption
o Altering rate of excretion
Keys to Understanding Minerals—(cont.)
• Mineral toxicities
– Stored minerals can produce toxicity symptoms.
– Toxicity related to excessive use of mineral
supplements, environmental or industrial
exposure, human errors in commercial food
processing, or alterations in metabolism
• Mineral interactions
– Mineral status must be viewed as a function of
the total diet.
Keys to Understanding Minerals—(cont.)
• Sources of minerals
– Unrefined or unprocessed foods have more
minerals than refined foods.
• Major electrolytes
– Sodium
o Salt (sodium chloride) is approximately 40%
sodium.
o Wide variations in sodium intake exist
between cultures and between individuals
within a culture.
Keys to Understanding Minerals—(cont.)
• Major electrolytes—(cont.)
– Sodium—(cont.)
o Major extracellular cation
o Largely responsible for regulating fluid balance
o Almost 98% of all sodium consumed is
absorbed.
o Adequate Intake for sodium is set at 1500
mg/day for young adults.
o One hundred percent of adult men and women
exceed the AI of 1500 mg of sodium per day.
Keys to Understanding Minerals—(cont.)
 Potassium
– Major cation of the intracellular fluid
– When potassium excretion is impaired, such as
secondary to diabetes, chronic renal insufficiency, endstage renal disease, severe heart failure, and adrenal
insufficiency, high potassium intakes can lead to
hyperkalemia and life-threatening cardiac arrhythmias.
 Chloride
– Major anion in the extracellular fluid
– AI for younger adults is 2.3 g/day.
Major Minerals
• Calcium
– Most plentiful mineral in the body
– Probably protects against colorectal cancer
– Calcium balance in the blood is achieved through the
action of vitamin D and hormones.
– Three daily servings of milk, yogurt, or cheese plus
nondairy sources of calcium are needed to ensure an
adequate calcium intake.
– An adequate calcium intake throughout the first three
decades of life is needed to attain peak bone mass as
determined by genetics.
Major Minerals—(cont.)
• Phosphorus
– After calcium, the most abundant mineral in the body
is phosphorus.
– About 60% of natural phosphorus from food sources
is absorbed.
– Dietary deficiencies of phosphorus do not occur.
– Involved in energy yield (ATP)
• Magnesium
– Fourth most abundant mineral in the body
– Co-factor in some enzymes-without Mg these
enzymes cannot work
Major Minerals—(cont.)
• Sulfur
– Does not function independently as a
nutrient but is a component of biotin,
thiamin, and the amino acids methionine
and cysteine
– There is no RDA or AI for sulfur.
Trace Minerals
• Impact on health is significant
• Too little of a trace mineral can be just as deadly as too
much.
• Iron
– Approximately two-thirds of the body’s iron is
contained in the heme portion of hemoglobin.
– Iron in foods exists in two forms: heme iron, found in
meat, fish, and poultry, and nonheme iron, found in
plants such as grains, vegetables, legumes, and nuts.
– Overall rate of iron absorption is only 10% to 15% of
total intake.
Trace Minerals—(cont.)
• Iron—(cont.)
– Only 1% to 7% of nonheme iron is absorbed
from plant foods when they are consumed as
a single food.
– RDA for iron is set at 8 mg for men and
postmenopausal women and at 18 mg for
premenopausal women.
– Iron deficiency anemia
o Microcytic, hypochromic anemia
o Pica
Trace Minerals—(cont.)
• Iron—(cont.)
– Potential for toxicity is moderate to high.
– Hemochromatosis
– Acute iron toxicity
• Zinc
– A regular and sufficient intake is necessary.
– Plays important roles in immune system
functioning and in wound healing
Trace Minerals—(cont.)
• Iodine
– Essential component of thyroxine (T4) and
triiodothyronine (T3)
– Approximately 50% of the population uses iodized
salt.
• Selenium
– A component of a group of enzymes that function as
antioxidants
– Selenium deficiency is rare in Canada.
Trace Minerals—(cont.)
• Copper
– Distributed in muscles, liver, brain, bones, kidneys,
and blood
– Involved in hemoglobin synthesis, collagen formation,
wound healing, and maintenance of nerve fibers
• Manganese
– Dietary deficiencies have not been noted.
– Co-factor for several enzymes
– High manganese intake from drinking water also
produces neuromotor deficits similar to Parkinson’s
disease.
Trace Minerals—(cont.)
• Fluoride
– Promotes the mineralization of developing tooth
enamel prior to tooth eruption and the
remineralization of surface enamel in erupted
teeth
– Fluoridation of municipal water
• Chromium
– Enhances the action of the hormone insulin to
help regulate blood glucose levels
– Appears that average intake is adequate
Trace Minerals—(cont.)
• Molybdenum
– Plays a role in red blood cell synthesis
– Dietary deficiencies and toxicities are
unknown.
• Other trace elements
– Evidence is difficult to obtain and quantifying
human need is even more formidable.
Water and Minerals in Health Promotion
• Water
– Recommended that thirst be the guide to
consuming adequate fluid; specific amounts or
types of beverages to satisfy fluid need are not
suggested
– For healthy people, hydration is unconsciously
maintained with ad libitum access to water.
• Sodium and potassium
– Recommendations
o Less sodium
o More potassium
Metabolism
METABOLISM IN GENERAL AND
VITAMINS IN METABOLISM
METABOLISM IN GENERAL AND
MINERALS IN METABOLISM
Energy Balance
Chapter 7
Energy Intake
• Calories come from carbohydrates, protein, fat,
and alcohol.
• The total number of calories in a food or diet can
be estimated by multiplying total grams of
carbohydrates, protein, or fat by the appropriate
number of calories per gram.
Energy Expenditure
• Basal metabolism
– Caloric cost of staying alive or the amount of
calories required to fuel the involuntary
activities of the body at rest after a 12-hour
fast
– Basal metabolic rate (BMR) accounts for
approximately 60% of total calories expended.
o The less active a person is, the greater the
proportion of calories used for basal energy
expenditure (BEE).
Energy Expenditure—(cont.)
• Basal metabolism—(cont.)
– Lean tissue (muscle mass) contributes to a
higher metabolic rate than fat tissue.
– Loss of lean tissue that usually occurs with
aging beginning sometime around age 30 is
one reason why calorie requirements
decrease as people get older.
Energy Expenditure—(cont.)
• Physical activity
– Accounts for approximately 30% of total
calories used
Calories In Versus Calories Out
• State of energy balance is the relationship
between the amount of calories consumed and
the amount of calories expended.
• A “positive” energy balance occurs when calorie
intake exceeds calorie output.
• A “negative” calorie balance occurs when calorie
output exceeds intake.
What Is “Normal” Weight
• “Normal” or “desirable” weight is that which is
statistically correlated to good health.
• Three criteria used for assessing overweight
and obesity
– Body mass index (BMI)
– Waist circumference
– Existing health problems
What Is “Normal” Weight—(cont.)
• Body mass index
– Body mass index (BMI) has replaced traditional
weight–height calculations that were used to determine
“ideal” or “desirable” body weight.
– Formula to calculate BMI is weight in kilograms divided
by height in meters squared.
– Drawback
o Does not take body composition or body fat
distribution into account
– Skinfold measurements and bioelectrical impedance
can assess body composition, but neither technique is
widely used.
What Is “Normal” Weight—(cont.)
• Waist circumference
– Location of excess body fat is a more important
and reliable indicator of disease risk.
– Storing a disproportionate amount of total body
fat in the abdomen increases risks for type 2
diabetes, dyslipidemia, hypertension, and
cardiovascular disease.
– Abdominal fat is clinically defined as a waist
circumference as per next slide
What Is “Normal” Weight—(cont.)
Country or ethnic group
European, Sub-Saharan African,
Eastern Mediterranean and Middle
Eastern (Arab)
South Asian, Chinese, Japanese,
South and Central American
Central obesity as defined by WC
Men - cm (inches)
Women - cm (inches)
94 (37.6) or greater
80 (32) or greater
90 (36) or greater
80 (32) or greater
What Is “Normal” Weight—(cont.)
• Existing health problems
– Presence of existing health problems impacts
a person’s absolute risk related to weight.
– Generally, the number and severity of
comorbid conditions increases with increasing
levels of obesity.
Energy Balance in Health Promotion
• Preventing or reducing overweight is achieved
by adopting a lifestyle approach that includes
healthier food choices, increasing physical
activity, and behavior modification.
Energy Balance in Health Promotion—
(cont.)
• Healthier choices
– Encompasses a two-pronged approach
o Eating less of certain items
o Eating more of others
– Emphasis is on healthy and wholesome choices.
o Remember fat-free foods still contain calories from
protein and carbohydrates.
– Reducing alcohol intake is another way to consume
fewer calories.
Energy Balance in Health Promotion—
(cont.)
• Portion control
– Portion sizes have grown over the last 20
years.
– “Portion distortion” appears to be a
widespread problem.
– Change the environment
o Food should be less accessible, less
visible, and proportioned in smaller
quantities.
Energy Balance in Health Promotion—
(cont.)
• Physical activity
– Benefits of increasing activity are dose dependent and
occur along a continuum.
– Yet we sit down and we chow down and we continue
as a population to increase waist circumferences.
– Minimum of 150 minutes per week of moderateintensity to vigourous physical activity helps to
control waist circumferences when combined with the
six dietary principles
How to Burn 150 Calories
(Based on a 150-Pound Person)
• Pedal a stationary bicycle for 20 minutes.
• Practice fast dance steps for 24 minutes.
• Work in the garden for 27 minutes.
• Walk briskly (6 km/hour) for 33 minutes.
• Clean the house for 38 minutes.
Suggestions for Increasing Activity
• Find something enjoyable.
• Use the buddy system.
• Spread activity over the entire day if desired.
• Start slowly and gradually increase activity.
• Move more.
• Keep an activity log.
Nutrition for Infants, Children,
and Adolescents
Chapter 12
Nutrition for Infants, Children, and
Adolescents
• Intake of adequate calories and nutrients
promotes optimal physical, social, and cognitive
growth and development.
• Children and adolescents who do not consume
enough calories and nutrients are at increased
risk of impaired health and certain chronic
diseases in adulthood.
• Actual nutrient requirements vary according to
health status, activity pattern, and growth rate.
Infancy (Birth to 1 Year)
• Parent and caregivers must model good eating and
exercise patterns from birth onwards.
• Growth in the first year of life is more rapid than at
any other time in the life cycle.
• Infant’s needs are much higher per kilogram of body
weight.
Infancy (Birth to 1 Year)—(cont.)
• Breast milk
– Specifically designed to support optimal
growth and development in the newborn
– Composition makes it uniquely superior for
infant feeding.
– Exclusive breastfeeding for the first 6 months
of life followed by optimal complementary
feeding are critical public health measures.
Infancy (Birth to 1 Year)—(cont.)
• Breast milk—(cont.)
– Adequacy of intake is determined by
monitoring weight for height on growth
charts.
– Research shows that breastfeeding
decreases the incidence and/or severity of
infectious diseases.
Infancy (Birth to 1 Year)—(cont.)
• Breast milk—(cont.)
– Some studies suggest that older children and
adults who were breastfed have a lower risk of
o Type 1 and type 2 diabetes
o Lymphoma and leukemia
o Hodgkin’s disease
o Overweight and obesity
o Hypercholesterolemia
o Asthma
Infancy (Birth to 1 Year)—(cont.)
• Breast milk—(cont.)
– Canadian Paediatric Society recommends exclusive
breastfeeding for the first 6 months of life.
– Even after solid foods are introduced at 6 months or
later, breastfeeding should continue until at least the
first 12 months of age. After 12 months breastfeeding
alone is insufficient to meet metabolic demands.
–
http://www.caringforkids.cps.ca/handouts/breastfeeding
–
http://www.caringforkids.cps.ca/handouts/feeding_your_baby_in_the_first_year
• Infant formula
– Infant formulas may be used in place of breastfeeding
(but breastfeeding is best if at all possible!!), to
supplement breastfeeding, or when exclusively
breastfed infants are weaned before 12 months of age.
Infancy (Birth to 1 Year)—(cont.)
• Infant formula—(cont.)
– Variety of formulas is available for infants with
special needs.
o Phenylketonuria (PKU)
o Maple syrup urine disease
– Low-birth-weight formulas
– The amount of formula provided per feeding and
the frequency of feeding depend on the infant’s
age and individual needs.
Infancy (Birth to 1 Year)—(cont.)
• Infant formula—(cont.)
– Overfeeding is one of the biggest hazards of formula
feeding.
– To avoid nursing bottle caries, infants and children
should not be put to bed with a bottle of formula,
milk, juice, or other sweetened liquid.
• Complementary foods: introducing solids
– Solids become a necessary source of nutrients
around 6 months of age.
Infancy (Birth to 1 Year)—(cont.)
• Complementary foods: introducing solids—(cont.)
– Eruption of teeth indicates readiness to progress from
strained to mashed to chopped fine to regular
consistency foods.
– Iron-fortified infant cereal is generally the first solid
food introduced.
o Give a small amount of formula or breast milk to
take the edge off hunger before beginning the
cereal
o Recommended until the infant is 12 to 18 months
old
Infancy (Birth to 1 Year)—(cont.)
• Complementary foods: introducing
solids—(cont.)
– Traditionally, the order of foods introduced
after iron-fortified cereals was
o Vegetables
o Fruits
o Meats
o Eggs
Infancy (Birth to 1 Year)—(cont.)
• Complementary foods: introducing solids—
(cont.)
– Order is no longer considered important.
– WHO and Pan American Health Organization
recommend that “meat, poultry, fish, or eggs
should be eaten daily or as often as possible.”
– New foods should be introduced in plain and
simple form one at a time for a period of 5 to 7
days.
Infancy (Birth to 1 Year)—(cont.)
• Complementary foods: introducing solids—
(cont.)
– Peanuts and peanut butter should be avoided.
– Infants differ in the amount of food they want
or need at each feeding.
– Infants and children should be allowed to selfregulate the amount of food consumed.
Nutrition for Toddlers
• The period between age 1 and 2 years is a time
of transition.
• At age 1 year, the toddler should be
– Drinking from a cup
– Eating many of the same foods as the rest
of the family
Nutrition for Toddlers—(cont.)
• Around 15 months of age, food jags may develop.
• By the end of the second year, children can completely
self-feed and can seek food independently.
• At age 1 year, whole milk becomes a major source of
nutrients.
– Milk anemia can occur.
• The Canadian Paediatric Society recommends that after
children turn 2 years old, one can offer lower fat milk
(1% or 2% MF) or milk alternatives. Wait until children
are at least 5 years old before offering skim milk.
Nutrition for Toddlers—(cont.)
• Until the age of 4 years, young children are at risk of
choking.
– Decrease the risk of choking
o Foods that are difficult to chew and swallow should
be avoided.
o Meals and snacks should be supervised.
o Foods should be prepared in forms that are easy
to chew and swallow (e.g., cut grapes into small
pieces and spread peanut butter thinly).
o Infants should not be allowed to eat or drink from
a cup while lying down, playing, or strapped in a
car seat.
Foods That Most Often Cause Choking
• Hot dogs
• Tough meat
• Candy
• Celery
• Nuts
• Popcorn
• Grapes
• Peanut butter
• Raw carrots
• Watermelon with seeds
Nutrition for Children
• Childhood represents a more latent period of
growth.
– Annually, a child grows 2 to 3 inches in
height and gains about 5 pounds.
• School-age children maintain a relatively
constant intake in relation to their age group.
Nutrition for Children—(cont.)
• Calories and nutrients
– Total calorie needs steadily increase during childhood.
– Calorie needs per kilogram of body weight
progressively fall.
– Challenge in childhood is to meet nutrient
requirements without exceeding calorie needs.
Nutrition for Children—(cont.)
• Eating practices
– As children get older
o They consume more foods from nonhome sources.
o Have more outside influences on their food choices
– Today
o Many children do not eat breakfast.
o Many obtain a significant portion of their calories
from sweetened beverages.
Nutrition for Children—(cont.)
• Promoting healthy habits
– Parents are the primary gatekeepers and role
models of their young children’s food intake and
habits.
– Children who eat more meals with their families
have healthier diets.
– Follow Canada’s Food Guide.
Nutrition for Adolescence
(12 to 18 Years of Age)
• The slow growth of childhood abruptly and
dramatically increases with pubescence until
the rate is as rapid as that of early infancy.
• Calorie and nutrient needs increase.
Nutrition for Adolescence
(12 to 18 Years of Age)—(cont.)
• Calories and nutrients
– Generally, nutrient requirements are higher during
adolescence than at any other time in the life cycle,
with the exception of pregnancy and lactation.
– Suggested amount of calories for moderately active
females aged 12 to 18 years is 2000 kcal, whereas
for males the need ranges from 2200 to 2800 kcal.
Nutrition for Adolescence
(12 to 18 Years of Age)—(cont.)
• Calories and nutrients—(cont.)
– Requirements for calcium and iron (for males only)
are higher during adolescence than at any other time
in the life cycle.
– Adolescents have increased needs for iron.
o In boys, peak iron requirement occurs at 14 to 18
years of age.
o Requirement for iron in adolescent girls increases
from 8 to 15 mg/day at the age of 14 years to
account for menstrual losses.
Nutrition for Adolescence
(12 to 18 Years of Age)—(cont.)
• Eating practices
– In early adolescence, peer pressure overtakes
parental influence on food choices.
o Risk of overeating
o Lack adequate fruits, vegetables, dairy foods,
and whole grains
– Nutrients most likely to be deficient
o Fiber, vitamin A, calcium, iron, and potassium
Nutrition Concerns
During Childhood and Adolescence
• Breakfast skipping
– Children aged 6 to 13 years
– Results in lower intakes of vitamins and
minerals
Nutrition Concerns During Childhood and
Adolescence—(cont.)
• Increased consumption of soft drinks
– In the last 50 years, the ratio of milk to soft
drink consumption has changed dramatically.
– Soft drinks and sweetened beverages provide
calories without nutrients.
– Soft drink consumption is linked to low intakes
of vitamins A and C, some B vitamins, calcium,
and phosphorus.
Nutrition Concerns During Childhood and
Adolescence—(cont.)
• Overweight and obesity
– The prevalence of obesity among youth has risen
dramatically in Canada.
– Overweight and obesity in childhood or adolescence
increase the risk of several diseases in adulthood.
– Overweight and obesity can have negative social and
psychological consequences.
– Fundamental cause of overweight and obesity is an
imbalance between calorie intake and calorie
expenditure.
Nutrition Concerns During Childhood and
Adolescence—(cont.)
• Healthy lifestyles and obesity prevention
– Prevention of obesity is critical.
– Barriers to parents taking action
o Lack of time
o Believe that children will outgrow their excess
weight
o Lack of knowledge
o Fear they will cause eating disorders
Nutrition Concerns
During Childhood and Adolescence—(cont.)
• Healthy lifestyles and obesity prevention—
(cont.)
– BMI and waist circumference calculated and plotted at each
well visit.
– Overweight or obese children and adolescents are helped
change their eating and physical activity behaviors to
prevent an increase in BMI and waist circumference and
that health professionals be consulted to manage weight.
Nutrition Concerns
During Childhood and Adolescence—(cont.)
• Adolescent pregnancy
– Associated with physiologic, socioeconomic, and
behavioral factors that increase health risks to
both infant and mother
– Infants are at risk for low birth weight and
premature birth and are more likely to die within
the first year of life.
– Pregnant adolescents are at higher risk for
anemia, high blood pressure, and excessive
postpartum weight retention.
Nutrition Concerns During Childhood and
Adolescence—(cont.)
• Compared with adult women, pregnant adolescents
– Are more likely to be physically, emotionally, financially,
and socially immature
– May not have adequate nutrient stores
– May give low priority to healthy eating
– May have poor intake and status of certain micronutrients
– Must gain weight early and steadily
– Are more concerned with body image
– Are more likely to smoke during pregnancy
– Seek prenatal care later
Nutrition for Older Adults
Chapter 13
Nutrition for Adults and Older Adults
• Adulthood represents a wide age range from
young adults at 18 to the “oldest old.”
• Adults over 50, and especially those over 70,
have different nutritional needs than do younger
adults.
Aging and Older Adults—(cont.)
• Aging demographics
– Ratio of older persons to younger persons is increasing
– Older persons are living longer than ever before
– Older people get sick due to aging processes and large
numbers of such persons stress the healthcare systemthe so-called “silver tsunami”
– As well older people may experience weight gain if they
do not manage calorie intake and physical activity
– But many younger people are not healthy either
(obesity and its sequelae) and this too stresses the
healthcare system
Aging and Older Adults—(cont.)
• Healthy aging
– Preventing disease is the key to healthy aging.
– Good nutrition
– Exercise
– Evidence shows that initiating healthy changes
even in one’s 60s and 70s provides definite
benefits.
Aging and Older Adults—(cont.)
• Nutritional needs of older adults
– Knowledge growing
– Health status, physiologic functioning, physical
activity, and nutritional status vary more among older
adults (especially people older than 70 years of age)
than among individuals in any other age group.
– Calorie needs decrease yet vitamin and mineral
requirements stay the same or increase.
– Two DRI groupings exist for mature adults.
o People age 51 to 70
o Adults over the age of 70
Aging and Older Adults—(cont.)
• Nutritional needs of older adults—(cont.)
– Calories
o Needs decrease with age.
o Changes in body composition
o Physical activity progressively declines.
o Estimated 5% decrease in total calorie needs
each decade
o Undesirable consequences of aging can be
improved or reversed.
Aging and Older Adults—(cont.)
• Nutritional needs of older adults—(cont.)
– Protein
o The RDA for protein remains constant at
0.8 g/kg for both men and women from
the age of 19 and older.
Aging and Older Adults—(cont.)
• Nutritional needs of older adults—(cont.)
– Protein—(cont.)
o Factors that may contribute to a low protein intake
 Cost of high-protein foods
 Decreased ability to chew meats
 Lower overall intake of food
 Changes in digestion and gastric emptying
o Groups at risk for inadequate protein intake
 Oldest elderly
 Those with health problems
 Those in nursing homes
Aging and Older Adults—(cont.)
• Nutritional needs of older adults—(cont.)
– Water
o The AI for water is constant from 19 years of age
through age 70 and above.
o Represents total water intake
o Elderly are able to maintain fluid balance.
o Altered sensation of thirst and an age-related
decrease in the ability to concentrate urine
increases risk for
 Dehydration
 Hyponatremia
Aging and Older Adults—(cont.)
• Nutritional needs of older adults—(cont.)
– Fiber
o The AI for fiber is based on median intake
levels observed to protect against coronary
heart disease.
 AI for fiber is 38 g/day for men through
age 50 years and 30 g/day thereafter.
 AI for fiber is 25 g/day for women from
19 to 50 years of age and 21 g/day
thereafter.
Aging and Older Adults—(cont.)
• Nutritional needs of older adults—(cont.)
– Vitamins and minerals
o Most recommended levels of intake for vitamins
and minerals do not change with aging.
o Significant exceptions
 Calcium
 Vitamin D
 Iron for women
o DRI for sodium decreases.
o People over 50 are advised to consume most of
their B12 requirement from fortified food or
supplements.
Aging and Older Adults—(cont.)
• Nutrient and food intake of older adults
– As calorie needs decrease with aging, so does
the quantity of food eaten and the amount of
calories consumed.
– Mean calorie intake falls by 1000 to 1200
cal/day in men and 600 to 800 cal/day in
women.
Aging and Older Adults—(cont.)
• Nutrient and food intake of older adults—(cont.)
– Consume less fruit and vegetables
– Older adults need to improve their intakes of
o Whole grains
o Dark green and orange vegetables
o Dried peas and beans
o Fat-free and low-fat milk and milk products
– Snacking in older adults may help ensure an adequate
intake.
Aging and Older Adults—(cont.)
• Vitamin and mineral supplements
– In theory, older adults should be able to obtain
adequate amounts of all essential nutrients
through well-chosen foods.
o Fifty percent of older adults have inadequate
intakes of vitamin E and magnesium.
– Supplements may be required for adults age 51
years and older.
Aging and Older Adults—(cont.)
• Nutrition screening for older adults
– Older adults at greatest risk of consuming an
inadequate diet are those who are
o Less educated
o Live alone
o Have low incomes
– Identifying nutritional problems in older adults
can be a challenge.
Screening Criteria for Malnutrition in
Older Adults
• Disease
– Do you have an illness that makes you change the
kind and/or amount of food you eat?
• Eating poorly
– Do you eat fewer than two meals a day? Do you eat
few fruits, vegetables, or milk products? Do you have
three or more drinks of beer, liquor, or wine almost
every day?
• Tooth loss/mouth pain
– Do you have tooth or mouth problems that make it
hard for you to eat?
Screening Criteria for Malnutrition in
Older Adults—(cont.)
• Economic hardship
– Do you sometimes not have enough money to spend
on the food you need?
• Reduced social contact
– Do you eat alone most of the time?
• Multiple medications
– Do you take three or more prescribed or over-thecounter drugs a day?
Screening Criteria for Malnutrition in
Older Adults—(cont.)
• Involuntary weight loss/gain
– Have you gained or lost 10 pounds in the last 6
months without trying?
• Needs assistance in self-care
– Are you sometimes not physically able to shop, cook,
and/or feed yourself?
• Elder years above age 80
– Are you older than age 80?
Nutrition-Related Concerns in Older Adults
• Should be client-centred and based on the
individual’s physiologic, pathologic, and psychosocial
conditions
• Overall goals of nutrition therapy for older adults
– Maintain or restore maximal independent
functioning and health
– Maintain the client’s sense of dignity and quality
of life by imposing as few dietary restrictions as
possible
Nutrition-Related Concerns in
Older Adults—(cont.)
• Cataracts and macular degeneration
– Prevalence of cataracts and age-related macular
degeneration (AMD) are increasing as the population
ages.
– AMD is the major cause of legal blindness in North
America.
– Appears that a multivitamin/multimineral supplement
containing vitamin C, vitamin E, beta-carotene, and
zinc is effective in slowing AMD but not cataracts.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Cataracts and macular degeneration—(cont.)
– Observational studies show that a diet rich in
antioxidants, especially lutein and zeaxanthin, and
omega-3 fatty acids benefits AMD and possibly
cataracts.
– People who eat diets high in refined carbohydrates
(high glycemic index) are at greater risk of AMD
progression than people who eat a less refined
carbohydrates.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Functional limitations
– Aging causes a progressive decline in physical
function.
– Major causes of functional limitations among
older adults include
o Arthritis
o Osteoporosis
o Sarcopenia
Nutrition-Related Concerns in
Older Adults—(cont.)
• Functional limitations—(cont.)
– Arthritis
o A leading cause of functional limitation among
older adults
o Osteoarthritis (OA) is associated with aging and
normal “wear and tear” on joints.
 Knee is the most commonly affected joint.
 Excess body weight is the greatest known
modifiable risk factor.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Functional limitations—(cont.)
– Arthritis—(cont.)
o Other risk factors for OA include genetics, age,
ethnicity, gender, occupation, exercise, trauma,
and bone density.
o Symptoms of OA usually appear after the age of
40 and by 65 years of age or above.
o Objective of treatment is to control pain, improve
function, and reduce physical limitations.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Functional limitations—(cont.)
– Osteoporosis
o Bone remodeling
o After menopause, women experience rapid
bone loss related to estrogen deficiency.
o Process actually begins early in life.
o Important to build sufficient bone mass
early in life to reduce the risk of
osteoporosis
Nutrition-Related Concerns in
Older Adults—(cont.)
• Functional limitations—(cont.)
– Osteoporosis—(cont.)
o Interventions implemented late in life can
effectively slow or halt bone loss.
– Sarcopenia
o Defined as loss of muscle mass and strength
o Chronic muscle loss is estimated to affect 30% of
people over the age of 60 and may affect more
than 50% of those over 80 years of age.
o Related to a sedentary lifestyle and less than
optimal diet
Nutrition-Related Concerns in
Older Adults—(cont.)
• Functional limitations—(cont.)
– Sarcopenia
o Strength training using progressive
resistance is the best intervention shown
to slow down or reverse sarcopenia.
o Adequate protein intake is also essential.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Alzheimer’s disease (AD)
– Most common form of dementia in Canada
– Risk of AD increases with increasing age.
– Cause of AD is unknown and there is no cure.
– Genetic and nongenetic factors (e.g.,
inflammation of the brain, stroke) have been
identified in the etiology of AD.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Alzheimer’s disease (AD)—(cont.)
– Development of AD may also be related to
oxidative stress.
– People who eat fish have less cognitive decline
than people who do not eat fish.
o DHA, an omega-3 fatty acid, may offer some
protection against AD.
– AD can have a devastating impact on an
individual’s nutritional status.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Obesity
– Major public health problem
– Appropriateness of treating obesity in older
adults is controversial.
o Weight loss can be harmful to older adults.
– Goal of weight loss therapy for older adults
should be to improve physical function and
quality of life.
Nutrition-Related Concerns in
Older Adults—(cont.)
• Social isolation
– Eating alone is a risk factor for poor
nutritional status among older adults.
o Congregate meals
o Meals on Wheels
o Modified diets, such as diabetic diets and
low-sodium diets, are provided as needed.
Long-Term Care
• Residents tend to be frail elderly with multiple
diseases and conditions.
• Malnutrition has a negative impact on both the
quality and length of life and is an indicator of
risk for increased mortality.
• Have same risk factors as those who live
independently
Long-Term Care—(cont.)
• Additional risks among long-term care residents
include
– Loss of appetite
– Pressure ulcers may be a symptom of
inadequate food and fluid intake.
– Dysphagia
– Loss of independence, depression, altered
food choices, and cognitive impairments can
negatively impact food intake.
Long-Term Care—(cont.)
• The downhill spiral
– Loss of appetite is a major cause of
undernutrition in long-term care.
– Undernutrition increases the risk of illness and
infection.
– Undernutrition is exacerbated and a downward
spiral ensues.
Long-Term Care—(cont.)
• The downhill spiral—(cont.)
– Intake assessment system is flawed.
o Food intake records may be neglected.
o Lack of skill in accurately judging the
percentage of food consumed
Long-Term Care—(cont.)
• Preventing malnutrition
– A quality of life issue
– Commercial supplements are often given
between meals.
– Potential benefits must be weighed against
the potential negative consequences.
– Increase of nutrient-dense foods included in
diet
Long-Term Care—(cont.)
• The use of diets
– Use of restrictive diets as part of medical care in longterm care facilities is controversial.
– Goals of preventing malnutrition and maintaining
quality of life are of greater priority.
– Restrictive diets
o Potential to negatively affect quality of life
o Should be used only when a significant
improvement in health can be expected
Long-Term Care—(cont.)
• A liberal diet approach
– Holistic approach is advocated.
– Low-sodium diets used in the treatment of
hypertension are often poorly tolerated by older
adults.
– Imposing dietary restrictions on long-term care
residents with diabetes is unwarranted.
– Epidemiologic studies indicate that the importance of
hypercholesterolemia as a risk factor for CHD
decreases after age 44 and virtually disappears after
the age of 65.
Long-Term Care—(cont.)
• A liberal diet approach—(cont.)
– Can be modified to meet the needs of residents
with increased needs
– Foods may be made more nutrient dense.
– Supplemental vitamin C and zinc may be ordered
to promote healing.
– Frequent and accurate monitoring of the
resident’s intake, weight, and hydration status is
vital.