Nutrition and the elderly Flashcards
What is healthy life expectancy in males and females and total life expectancy?
HLE:
Males- 63.5
Females- 65.7
Total:
Males- 78.1
Females- 82.1
What percentage of mass is fat and lean?
Fat-25%
Lean-75%
What is the fat store like?
A pure energy store
Metabolically inactive
Contracts if energy demand>intake and expands if other way
Stored Kcal: 150,000
What is the lean mass store like?
70% water, 20% protein and 10% mineral Metabolically active Compartment size highly regulated Potential kcal: 40,000 Contains all skeletal and smooth muscles (tissue, skin, collagen, cell structure, enzymes, Abs, growth factors, visceral proteins)
How does body composition change with age?
Fat mass increases until about 75 then decreases
Fat may also be redistributed centrally with age
Fat free mass starts to decrease in middle age slowly and after about 60 years, the rate of FFM loss increases
Significant difference between %FFM in old and young subjects of all BMI
What changes in body composition are there in starvation and disease?
Starvation- loss of lean and fat mass
Disease may contribute to changes in body composition- increased FFM loss, changes in hydration. FFM loss but stable weight
What is the aetiology of ageing associated weight loss?
Wasting- negative energy balance due to reduced food intake. Linked to appetite loss
Cachexia- Active immune response (TNF, cytokines), increased REE, protein catabolism
Sarcopenia
What is the metabolic response to short term starvation?
Decreased overall energy needs
Decreased metabolic rate 20-25kcal/kg/d
Energy from fat storage >90% of kcal
Energy from protein <10% for gluconeogenesis
What occurs in sarcopenia?
FFM decreases by between 2-5% per decade
Mainly skeletal muscle
Also bone and water
Higher the peak of FFM, further you have to fall and slower the rate until disability threshold is reached
What complications are there relative to % loss of LBM?
10%- Impaired immunity and increased infection
20%- Decreased healing, weakness, infection
30%- Too weak to sit, pressure, sores, pneumonia, no healing
40%- Death, usually from pneumonia
How does bone mineral density change throughout life?
Starts at 30 years- rates of about 0.7-1%/year upto 50 years. Increased rates in women post menopause- 2-3% year
Men continues at 0.7-1%/year
By 65 years average loss of 20% from 20 years old
How does body water change with age?
Decline in renal function and thirst perception
Reduction of total body water
Decreases in parallel with reduction of FFM
Reduction of 12% in people over 65 with respect to 19-34 years old
What are the clinical implications of ageing?
Decreased body energy stores and increased risk of malnutrition
Central accumulation of fat-risk of stroke, diabetes, hyperlipidaemia, heart disease and hypertension
Reduced muscle mass results in increasing weakness, affects mobility, respiratory function and independence
Bone mineral loss- fragile bones and increased risk of fractures
Increased risk of dehydration
How do nutritional requirements change with age?
They decrease gradually after 50-60 years- less active and BMR is reduced
How does protein change?
No difference
