13) Fat, Carbohydrate, Water, Mineral, Electrolyte, and Vitamin Requirements in Adulthood and the Elderly

Question 1

What are the different age categories to define nutrient requirements in the elderly?

Answer 1

• Under 50
• Between 51 and 70
• Over 70

Question 2

Why do distinct seniors possess different physiological and biological ages, despite having the same chronological age?

Answer 2

High heterogeneity of older adults in terms of diets, lifestyles and illnesses

Question 3

How does the energy requirement vary in the elderly?

Answer 3

• The requirements are the same

- However, the elderly has decreased energy requirements due to their low muscle mass, which decreases their BMR

Question 4

How does the protein requirement vary in the elderly?

Answer 4

• The requirements are the same (0.8 g/kg/day)

- However, recent studies have shown that this is insufficient

Question 5

Why wouldn’t nitrogen balance studies produce accurate data in the elderly in terms of protein requirements?

Answer 5

• Does not reflect the redistribution of protein in the body
• The rate of protein turnover in muscle is relatively slow, and it is unlikely that nitrogen balance studies may detect a significant change in muscle mass

Question 6

Which types of elderly individuals are less likely to benefit from protein supplementation?

Answer 6

Individuals with cachexia have less benefits than frail or individuals with sarcopenia

Question 7

Most of the patients with (cachexia/sarcopenia) present with (cachexia/sarcopenia), but the opposite is not true.

Answer 7

cachexia

sarcopenia

Question 8

Define cachexia.

Answer 8

• Complex metabolic syndrome, associated with underlying illness
• Characterized by muscle mass with or without the loss of fat mass

Question 9

What are prominent clinical features of cachexia?

Answer 9

• Weight loss, inducing a rapid loss of muscle caused by an accelerated rate of protein breakdown
• Inflammation, increased muscle breakdown and insulin resistance

Question 10

Does the ingestion of protein induce an anabolic effect in the elderly?

Answer 10

The response is lowered in the elderly, and the threshold is lower

Question 11

Which pro-inflammatory cytokines may interfere with the hormonal control of muscle metabolism?

Answer 11

• IL-6 and TNF-a cause insulin resistance and reduced levels of testosterone and LH
• Increase in fat mass –> increase in pro-inflammatory cytokines

Question 12

What may partially explain the lean body mass loss during aging?

Answer 12

The decreased ability of muscle to respond to anabolic stimuli, provided by dietary protein

Question 13

Which micronutrient may affect lean body mass, acting synergistically with dietary protein?

Answer 13

Vitamin D

Question 14

How does the carbohydrate requirement vary in the elderly?

Answer 14

The requirements are the same

Question 15

Why are the carbohydrate requirements the same in the elderly?

Answer 15

• Total body glucose oxidation rate decreases with age (modestly)
• Brain mass slowly decreases with age
• The decrease in brain glucose oxidation rate is not likely to be substantially less

Question 16

How does the fiber requirement vary in the elderly?

Answer 16

The requirements are the same (AI = 14 grams/1000 kilocalories)

Question 17

How does the omega-6 requirement vary in the elderly?

Answer 17

Decrease with age, given the decreased energy requirements of the elderly

Question 18

How does the omega-3 requirement vary in the elderly?

Answer 18

The requirements are the same

Question 19

How does the water requirement vary in the elderly?

Answer 19

The requirements are the same

Question 20

How are the water requirements determined in the elderly? Why?

Answer 20

• Based on median total water intake of young adults
• To ensure that total water intake is not limited due to a potential declining ability to consume adequate amounts of water in response to thirst
• The thirst mechanism is impaired with age

Question 21

How does the sodium requirement vary in the elderly?

Answer 21

The requirements decrease

Question 22

Why does the sodium requirement decrease in the elderly? How is the AI determined?

Answer 22

• The AI is extrapolated from younger adults

- The energy intakes decrease with age, and so sodium requirements decrease as well

Question 23

How are the requirements for water-soluble vitamins determined in the elderly?

Answer 23

Based on the proportional requirements (extrapolated from young adults), as there is little evidence of increased requirements in the elderly

Question 24

Why is vitamin B12 deficiency an issue in the elderly?

Answer 24

• 10 to 30% of mature adults lose their ability to adequately absorb protein-bound vitamin B12 in foods
• Because they are afflicted with atrophic gastritis

Question 25

How does the bioavailability of crystalline vitamin B12 differ in individuals with atrophic gastritis? What is it?

Answer 25

• Crystalline B12 = unbound vitamin B12 (fortified foods, supplements)
• It is NOT altered in individuals with atrophic gastritis

Question 26

How does the vitamin B12 requirement vary in the elderly?

Answer 26

• The requirements are the same
• However, the recommendation is the consumption of the majority of vitamin B12 through supplements and fortified foods (crystalline B12)

Question 27

How does the vitamin D requirement vary in the elderly? Why?

Answer 27

• The requirements are increased

- The absorption decreases, likely due to a decreased number of vitamin D receptors

Question 28

What are the dietary recommendations of vitamin D based on?

Answer 28

The amount of vitamin D to maintain blood levels of calcitriol associated with optimal bone health

Question 29

How does the calcium requirement vary in the elderly? Why?

Answer 29

• The requirements are increased

- The absorption decreases

Question 30

How do magnesium requirements vary with aging? Why? At what age?

Answer 30

• Magnesium requirements are greater in individuals over 30 years of age
• Renal status decreases after 30 years of age

Question 31

What are the factors implicated in determining iron requirements in the elderly?

Answer 31

Only basal iron losses