Life Cycle Nutrition:
The Adult Years
Chapter 16
Life Expectancy: 1900 vs. 1980
How long can you expect to be healthy?
What Causes Aging?




As organisms become older, number of cells
decreases and function of remaining cells
declines
As tissues and organs lose cells, ability of
organism to maintain homeostasis decreases
Loss of cells occurs throughout life but is not felt
for a long time, as organisms begin with reserve
capacity
Reserve capacity diminishes as we age, and we
begin to feel the effects of aging
What Affects the Rate of Aging?
Nutrient Needs in Adulthood

Energy needs typically
decline with age

– Decreased BMR

– More challenging to meet
these needs in older age
Protein, fat, and CHO
needs remain about the
same
– Protein: 0.8 g/kg body
weight
– Fat: 20-35% of kcals
• Avoid trans-fat, get
ample EFAs
– CHO: 45-65% of kcals
• Fiber important for
prevention of GI issues
and chronic illness
Water: needs remain
the same as we age
• Decreased sense of
thirst
• Kidneys decline in
function, increasing
losses

Micronutrients
– Recommendations
remain the same for most
as we age
• Increases in
recommendations for
B6, calcium, vitamin D,
and magnesium
• Decrease in iron
recommendation for
women past
menopause
Consequences of Malnutrition
Nutritional Strategies in
Older Age
Maximize nutrient density
 Nutritional supplements may be useful

– Decreased overall intake
– Decreased absorptive capacity
– Take care to avoid excesses
– Check with healthcare provider to rule out
drug-nutrient interactions
Changes in Body Composition
with Age
Importance of Physical Activity

Extends years of
active, independent life
 Reduces disabilities
 Improves overall
quality of life and
health
– Bone strength
– Muscle mass
– Cardiorespiratory
function
– Increases discretionary
kcalorie allowance