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

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– More challenging to meet

these needs in older 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