Nutrition And Lifecycle: Adults Flashcards
1
Q
BMI classes
A
- <18.5: underweight, risk of higher mortality (cardiac cachexia)
- 18.5-24.9: healthy weight
- 25- 29.9: overweight (pre-obese)
- 30-34.9: obese class I (cut off point for using waist circumference as indicator of health)
- 35-39.9: obese class II
- 40+: obese class III
2
Q
UK obesity facts (2015)
A
- 75% women over the age of 45 are overweight or obese
- prevalence obesity 26% (rising from 15% in 1993)
- white men had the highest BMI, asian men had lowest
- black women had highest BMI, with 60% at risk of developing TIIDM
- the richer the london borough, the lower the obesity rate
3
Q
Health risks of obesity
A
- high risk: TIIDM, insulin resistance, sleep apnea
- medium risk: CHD, hypertension, osteoarthritis
- slightly higher risk: cancer, PCOS, impaired fertility
4
Q
Causes of obesity
A
- trend towards eating higher kcal diets, higher in vegetable oils and sucrose (sugar)
- urbanisation: obesogenic environment. Easy access to food
- lower physical activity
- poorer diet quality
- diet- energy density cost factor: eating more energy dense food which are easy to digest
- more energy dense food is cheaper
5
Q
Features of metabolic syndrome
A
- obesity: high BMI, waist circumference
- abnormal blood lipids: low HDL, high triglycerides
- hypertension
- high blood glucose (diabetes risk)
6
Q
Reference values for MetS from IDF (2005)
A
- central obesity + 2 risk factors
- bmi: >30kg/m2
- waist circumference: >94 cm men, >80 cm women
- blood pressure: >130/85 mmHg
- fasting blood glucose: >5.6 mmol/L or previous diabetes
- fasting blood lipids: triglycerides >1.7 mmol/L, HDL <1.03 mmol/L men, <1.3 mmol/L women
7
Q
CVD risk factors
A
- modifiable: obesity (but BMI only increases relative risk in conjunction with another factor), smoking, reduced physical activity, hypertension, dyslipidemia, stress
- unmodifiable: age, gender, ethnicity, previous medical history
8
Q
Factors involved in development of atherosclerosis
A
- process: ‘response to injury’ hypothesis. Endothelium damaged (possibly due to hypertension, dyslipidemia), causing infiltration of LDL-> oxidised, and macrophages engulf-> foam cells. This induces proliferation of smooth muscle. Formation of plaques which can eventually occlude vasculature
- inflammation, immune response, ROS, LDL= not just cholesterol
- homocysteine may also induce atherosclerosis (involved in methylation pathway from methione), so low vitamin B12 MAY play a role= inconclusive
9
Q
The French Paradox
A
- compared to other european countries (Finland) with similar cholesterol saturated fat index, has comparably lower morbidity and mortality from CHD
- myriad of factors: PA, diet, smoking (higher prevalence but lower frequency), socio-economic factors (siesta, lower stress), red wine (resvanatrol), lack of processed foods, more natural oils used
- wine drinkers were found to have higher rates of PA, lower kcal diets (with more veg and fruit), drank less, lower saturated fat
10
Q
Factors affecting lower TDEE in elderly
A
- anorexia of ageing: reduced palatability of food (reduction in smell and taste), disturbed thyroid hormones, higher leptin and glucagon (satiety), lower ghrelin, down-regulated neuropeptide Y in hypothalamus
- lower PA as may have reduced mobility
- loss of FFM which lowers BMR and also PA
- lower TEF as may be eating less
- less able to regulate energy expenditure, less predictable response to over and under feeding
- mitochondrial dysfunction
11
Q
Definition of frailty
A
- clinically recognisable state of increased vulnerability resulting from ageing-associated decline in reserve and function across multiple physiologic systems such that the ability to cope with everyday stressors is compromised
- Fried et al definition: unintentional weight loss, self reported exhaustion, weakness, slow walking speed, low physical activity
12
Q
Causes and consequences of sarcopenia
A
- cause: disease and chronic undernutrition
- sarcopenia: loss of muscle mass, strength and function (impaired quality: more intra-muscular fat). Can have sarocpenic obesity (increased fat mass) or pre-cachexia (decreased fat mass). Can measure via DEXA or CT or SARCF questionnaire
- consequences: reduced VO2 max, power and strength (dynapenia), walking speed, activity and TDEE. Increased disability and dependency. Contractile insufficiency, metabolic impairment (anabolic, insulin resistance, glutamin depletion, decreased antioxidant capacity)
- lower muscle mass is key indicator of mortality
13
Q
Mechanisms behind sarcopenia
A
- reduced GH-IGF
- insulin resistance (insulin anabolic)
- reduced androgens (men)
- inflammation: NFkB recruits inflammatory cytokines which blunts muscle anabolism
- reduced vitamin D and thyroid activities
- anabolic resistance
14
Q
Recommendations for avoidance of sarcopenia
A
- 1.5g/kg/day protein, split into 4 meals (max anabolism) with 25-30g per meal (10g with essential amino acids and leucine rich)
- resistance training (synergistic effect with increased protein intake)
- L40 supplement (leucine supplement- increases protein anabolism)
15
Q
Drug treatments for sarcopenia
A
- fish oil/ NSAIDS: reduce inflammation (NFkB recruitment of cytokines) which would normally blunt muscle anabolism
- anabolic steroids
- SARMS (selective androgen receptor modulators): effects of testosterone without prostate atrophy
- ACE inhibitors: blood pressure
- anti- myostatin and inflammatory drugs under trials now (may have implications for cancer cachexia)
