1.1 Nutrition, Diet & Body Weight Flashcards
(16 cards)
What are the essential components of the diet?
- carbohydrates (mono, oligo & polysaccharides)
- lipids (37KJ/g)
- proteins (17KJ/g)
- minerals
- vitamins
- water (30ml/kg/day)
- fibre
also alcohol 29KJ/g.
Define the components of daily energy
expenditure.
Energy in the form of chemical bond energy (ATP).
1KCal: amount of energy needed to raise the temperature of one kilogram of water by 1 degrees celcius.
Sum of:
- basal metabolic rate (BMR)
- diet induced thermogenesis (DIT)
- physical activity level (PAL)
BMR:
- biosynthetic work, creating cellular components
- moving ions/nutrients across membranes
- muscle contraction
- nervous conduction
- osmosis (e.g. in kidneys)
DIT needed to process food.
PAL also varies - thinking age/sex/body composition.
Describe the factors involved in the regulation of
body weight.
energy intake > expenditure —> energy stores of adipose increases.
vice versa…
Determine the Body Mass Index and interpret
the value.
BMI (Kg/M2) = weight (kg) / height (m) squared.
Measured without shoes, minimal clothing.
Poor tool in cases of muscular people.
<18.5 = underweight
18.5-24.9 = desirable weight
25-29.9 = overweight
30-34.9 = obese
>35 = severely obese.
Explain the clinical consequences of protein
and energy deficiency.
20 amino acids, of which 9 are essential - cannot be synthesised and only obtained from food.
Some amino acids become conditionally essential, where the supply does not meet demand - e.g. in pregant woman. These are: arginine, tyrosine and cysteine.
Animal protein = high quality, Plant protein = low quality.
Due to animal meat containing all essential amino acids.
Muscle proteins are convered to energy under extreme conditions.
Maramus is a type of protein-energy malnutrition - children appear emaciated, signs of muscle wastage, loss of body fat and thin/dry hair. No odema. Diarrhoea and anaemia is common.
Which 9 amino acids are considered essential always?
Isoleucine, Lysine, Threonine, Histidine, Leucine, Methionine, Phenylalanine, Trypophan & Valine
“If learned this huge list may prove hugely valuable.”
Which vitamins are fat soluble?
A, D, E, K.
Which fatty acids are essential?
Linoleic & Linolenic acid.
What is the function of minerals, including some examples?
Calcium + Phosphurus: Essential for bone and teeth structure.
Calcium also acts as a signalling molecule.
Iron is necessary for haemoglobin to carry oxygen.
What are the 3 electroytes and their primary function?
Sodium, potassium, chlorine.
1mmol/kg/day required of each.
Establishes ion gradients across membranes.
What are the consequences of high and low fibre diets?
18g recommended daily.
Low: Constipation more likely & bowel cancer risk up.
High: Reduced cholesterol, reduced diabetes chance.
What values are published for recommended nutrient intake?
Dietary Reference Values (DRV):
- Reference nutrient intake (RNI): protein, vitamins and minerals. Sufficient for 97.5% of the population.
- Estimated Average Requirement (EAR): energy. Sufficient for 50%. 50% will need more.
- Lower Reference Nutrient Intake (LRNI).
Values vary by age, gender and level of physical activity. Generally apply only to a group, as individual requirements will vary.
What factors affect the basal metabolic rate (BMR)?
- surface area
- gender (higher in males than females)
- environmental temperature
- endocrine status (increases with hyperthyroidism)
- body temperature
What is an alternative to BMI?
waist to hip ratio.
Distribution of body fat has different implications. What conditions are at increased risk with fat in the upper half?
- insulin resistance
- hyperinsulinism
- type 2 diabetes
- hypertension
- hyperlipidaemia
- stroke
- premature death
What is the difference between marasmus and kwashikorker?
Marasmus is complete starvation - no food, no water, hence no pitting odema. Kwashikorker is carbs, fats and water but NO protein.
