Week 10: Nutrition in special populations

Question 1

Healthspan

Answer 1

Amount of time an individual spends in a state of good health
(what matters and can be modified)

Question 2

Lifespan

Answer 2

Number of years in an individuals life

Question 3

Lifestyle behaviours that influence health

Answer 3

1. Sleep
2. Eating well-balanced diet
3. Physical activity
4. Not smoking
5. Not using alcohol
6. Healthy body weight

Question 4

Sarcopenia

Answer 4

Age-related continuous involuntary decline in muscle mass, quality and strength

Question 5

What is sarcopenia characterized by?

Answer 5

Decreased size and number of type 2 skeletal muscle fibres and an infiltration of adipose tissue in skeletal muscle

Question 6

When do we begin to lose skeletal muscle?

Answer 6

40 years old

Question 7

How much muscle mass is lost per year after age 40?

Answer 7

0.5-1.0%

Question 8

How much muscle strength is lost per year after age 40?

Answer 8

1.2%

Question 9

What is the best predictor of falling?

Answer 9

Muscle strength

Question 10

Frailty

Answer 10

Reduction of the physiological functional reserve and a decreased homeostatic capacity leading to greater vulnerability to adverse health outcomes and increased risk of death

Question 11

Characteristics of a frail adult

Answer 11

1. Impaired mobility
2. Loss of strength
3. Slow gait speed
4. Unintended weight loss

Question 12

What is one reason we lose skeletal muscle mass as we age?

Answer 12

Energy intake is reduced

Question 13

How is energy intake reduced in older adults?

Answer 13

1. Decreased REE due to a reduction in FFM
2. Reduction in appetite
3. Reduction in physical activity levels

Question 14

Why is there a reduction in appetite in older adults?

Answer 14

1. Diminished hunger and satiety mechanism
2. Age-related gastrointestinal motility changes
3. Other factors (ie. depression)

Question 15

Why is there diminished hunger and satiety mechanism in older adults?

Answer 15

Altered hormonal response such that the production of orexigenic hormones are decreased and anorexigenic hormones are increased

Question 16

Which hormones are altered in older adults appetite reguation?

Answer 16

Decreased ghrelin and NPY
Increased CKK, PYY, insulin and leptin

Question 17

What are age-related gastrointestinal changes?

Answer 17

Delayed gastric emptying–> postprandial satiety–>reduced antral stretch (food in GI tract longer=feel full)

Question 18

Where is CKK produced and in response to what?

Answer 18

Small intestine in response to fat and protein

Question 19

Anorexia of aging

Answer 19

Decrease in appetite and food intake in old age

Question 20

What does anorexia of aging lead to?

Answer 20

Muscle wasting
Impaired immune function
Cognitive decline
Decreased function in respiratory muscles
Reduced gut function
Disability

Question 21

What is another reason we lose skeletal muscle mass as we age?

Answer 21

Lack of protein intake

Question 22

How do we increase muscle mass?

Answer 22

MPS>MPS such as with resistance training

Question 23

Why does muscle mass decrease?

Answer 23

MPS<MPB such as after an immobilization injury

Question 24

RDA for protein intake

Answer 24

0.8 g/kg/day
Designed to prevent deficiency but is not the optimal dose

Question 25

Rates of MPS and muscle mass in older adults

Answer 25

Older adults are less responsive to the protein they consume and therefore have less stimulation of MPS and less muscle mass

Question 26

MPS curve in older adults

Answer 26

Less elevation in MPS Same elevation in MPB

Question 27

Anabolic resistance

Answer 27

Reduced rise in MPS in response to the ingestion of protein/amino acids

Question 28

Solutions to reduced muscle mass in older adults

Answer 28

More protein to maximally stimulate muscle in a single meal

Question 29

How much protein was found to maximally stimulate muscle mass in older adult per meal?

Answer 29

0.4g/kg/per meal

Question 30

Protein intake in older adults

Answer 30

Skewed But balancing it across meals may result in improvements in MPS

Question 31

Study 1: Protein intake and MPS in middle aged adults

Answer 31

Consuming even protein intake across meals maximally stimulated MPS

Question 32

Study 2: Protein intake and timing on MPS in older adults

Answer 32

Protein intake is a signifiant predictor of stimulating MPS Balanced protein intake did not alter skeletal MPS in older adults

Question 33

Oral nutritional supplements

Answer 33

For those with dysphagia (difficulty swallowing) these can be used to increase nutrition and calorie intake

Question 34

Agility and physical activity

Answer 34

2 weeks of acute physical inactivity (step reduction) reduces rates of MPS and skeletal muscle mass in older adults

Question 35

EAA and MPS

Answer 35

Eating whey protein that contains all the EAA protects against declines in MPS

Question 36

Catabolic crisis model

Answer 36

Older adults have a harder time returning to lean muscle mass baseline after an injury due to anabolic resistance

Question 37

Gradual sarcopenia

Answer 37

The normal decline in skeletal muscle mass as we age

Question 38

Fat infiltration of skeletal muscle

Answer 38

Associated with negative health outcomes More prevelant in sedentary older adults

Question 39

Resistance training and protein

Answer 39

Both stimulate muscle growth even in older adults