Lecture 1 - Nutrition Flashcards
(38 cards)
What are the essential components of a diet?
- Carbo: energy
- Protein: energy & a/a
- Fat: energy & f.a
- Minerals
- Vitamins
- Water: hydration
- Fibre: normal GI function
How does fibre maintain normal GI function?
- Fibre reduces plasmic cholesterol/reduce risks of bowel cancer
- Binds to bile salts in GI tract and removed in faeces
(Bile salts are recycled by liver, but if fibre binds to it–> make more–> more cholesterol removed)
Why isn’t cellulose digested by the body?
- Cellulose-β-1,4 sugar link X digested by body, lack enzymes
N.B Glucose is α-1,4
What are the 9 essential amino acids?
If - Isoleucine (glucogenic) Learned - Lysine (ketogenic) This - Threonine Huge - Histidine List - Leucine May - Methionine Prove - Phenylalanine Truly - Tryptophan (both) Valuable - Valine
Children and pregnant women have higher rate of protein synthesis. Which a/a do they need more of?
Arginine, Tyrosine & Cysteine
not essential a/a but CONDITIONALLY essential
What are some examples of essential fatty acids?
Linoleic & Linolenic
What is the importance and some examples of minerals?
- Establish ion gradients across membranes
- Ca & K: bone structure
- Ca: Hormone secretion, muscle contraction, exocytosis, nerve conduction
What are some nutrient requirement guidelines?
*values depend on age, gender and physical activity
- RNI (Reference Nutrient Intake): for protein,vitamins & minerals
- EAR (Estimated Average Requirement): for energy
- LRNI (Lower Reference Nutrient Intake)
How are the nutritional guidelines calculated?
- Plot frequency over nutrient requirement bell curve
- 1st decile= LRNI, mean= EAR, 3rd decile= RNI
(decile within 2 s.d of mean)
LRNI: enough for small amount of ppl who have low requirements
RNI: 97.5% needs met
What factors are involved in the regulation of body weight.
Age, Sex, Body Comp, Physical activity
What is the moderate physical activity of a 70kg adult male and a 58kg adult female a day?
- Male =12,000 kJ/day
- Female= 9,500 kJ/day
What is the basal metabolic rate (BMR) and how is it calculated?
- Energy required to maintain resting activities of body:
i) maintenance of cells
ii) function of organs
iii) maintain body temp - Calculation: weight in kg x 100
What are some factors that affect BMR?
- Body size
- Gender
- Environment temperature
- Body Temp. (12% increase per degree)
- Endocrine regulation
What is voluntary physical activity?
- Energy required by skeletal, respiratory and cardiac muscle for voluntary contraction
What are the rough values of voluntary physical activity of a sedentary person, moderate activity and very active?
- Sedentary: 30kJ/Kg/day
- Moderate: 65 kJ/Kg/day
- Active: 100kJ/Kg/day
What is obesity?
- Excessive fat accumulation in adipose tissue
- BMI (>30)
How to calculate BMI and what are its ranges?
- Weight (kg)/ Height (m)^2 (units kg/m^2)
- Range same for both sexes
1. Underweight: <18.5
2. Optimal weight: 18.5-24.9
3. Overweight: 25-29.9
4. Obese: 30-34.9
5. Severely Obese: >35
Suggest an alternative way to measure whether very muscular individuals other than BMI
- Waist:Hip
- Obese: Men >0.9, Women >0.84
What risks are increased abdominal fat associated with?
- Insulin resistance
- Hyperinsulinism
- Type 2 DM
- Hypertension
- Hyperlipidaemia
- Stroke
- Premature Death
What is marasmus? State symptoms and signs.
usually children under 5
- Protein-energy malnutrition
- Emaciated appearance
- Muscle wasting
- Loss of body fat, no oedema
- Thain and dry hair
- Diarrhoea
- Anaemia
What is kwashiorkor and its symptoms? When does it occur?
- Occurs when a young child is displaced off breastfeeding and replaced with carbo. but low protein diet (cassava)
- Symptoms:
1. Child is disinterested, lethargic and anorexic
2. Generalised/Pitting oedema
3. Abdomen is distended (hepatomegaly)
4. Serum albumin low
5. Anaemia common
Why does oedema occur in kwashiorkor?
- Low protein diet –> insufficient a.a–> decrease plasma oncotic pressure –> ⬆️net flow of fluid from capillaries to I.F–> oedema
What is refeeding syndrome and when does it occur?
- Rapid refeeding of energy rich foods in starved/malnourished patients
- Result in rapid increase in BG–> increase protein synthesis–> utilise phosphate,Mg,K (depleted)–> electrolyte abnormalities (hypophosphatemia)
What should be done to prevent refeeding syndrome and what are its risk factors?
- Re-feed 5-10kcal a day. Raise gradually to full needs.
- Risk factors:
1. BMI (<16)
2. Unintentional weight loss of >15% in 3-6 months
3. 10 days with no/little nutritional intake
