Session 1-Nutrition, Diet&Body Weight Flashcards
What is metabolism?
The chemical processes that occur within a living organism in order to maintain life
What are catabolic processes?
Breakdown of molecules to release energy in the form of reducing power
What are anabolic processes?
Use energy and raw materials to make larger molecules for growth and maintenance
What is energy?
The capacity to do work
All living things constantly require energy for which processes? (5)
1) biosynthetic work
2) transport work
3) mechanical work (muscle contraction)
4) electrical work
5) osmotic work (kidney)
Which type of energy do cells use to drive energy-requiring activities?
Chemical bond energy
Energy is produced by the oxidation of what? (4)
1) lipids
2) carbs
3) protein
4) alcohol
What is the SI unit of food energy?
Kilojoule
How many kJ in 1 kcal?
4.2
What is the general formula for carbs?
(CH2O)n
What is an example of an oligosaccharide?
Dextrin
What is the predominant sugar in human blood?
Glucose
What is the glucose-glucose disaccharide?
Maltose
What is the carb storage molecule in plants?
Starch
What is the carb storage molecule in animals?
Glycogen
Which mnemonic is used to remember the 9 essential amino acids?
If-Isoleucine Learned-Lysine THis-THreonine Huge-Histidine List-Leucine May-Methionine Prove-Phenylalanine TRuly-TRyptophan Valuable-Valine
Which other AA do children and pregnant children require?
Arginine
Tyrosine
Cysteine
Why is protein of animal origin considered “high quality”?
Contains all essential AA
Why are proteins of plant origin generally considered lower quality?
Most are deficient in one or more essential AA
What are lipids composed of?
Triacylglycerols
True or false: lipids contain much less O2 than carbs or protein so they yield more energy when oxidised
TRUE
Fat is needed for the absorption of fat-soluble vitamins. What are the four fat soluble vitamins?
A, D, E and K
What are two types of essential fatty acids which cannot be synthesised in the body?
Linoleic acid
Linolenic acid
What do electrolytes establish and maintain?
Establish ion gradients across membranes
Maintain water balance
Which two minerals are essential for structure (bone and teeth)?
Calcium
Phosphorus
What does vitamin A deficiency result in?
Xerophthalmia
What does vitamin D deficiency result in?
Rickets
What does vitamin E deficiency result in?
Neurologic abnormalities
What does vitamin K deficiency result in?
Defective blood clotting
What does vitamin B12 deficiency result in?
Anaemia
What does vitamin B6 deficiency result in?
Dermatitis, anaemia
What does vitamin C deficiency result in?
Scurvy
What does a choline deficiency result in?
Liver damage
What does a folate deficiency result in?
Neural tube defects
Anaemia
What does a niacin deficiency result in?
Pellagra (dermatitis, diarrhoea and dementia)
What does a riboflavin deficiency result in?
Ariboflavinosis
Why is cellulose not digested in humans?
Humans do not produce the required enzymes to break the beta-1,4 linkages in cellulose
Where can dietary fibre be found?
Cereal foods (eg bread, beans, fruit and veg)
What is low fibre intake associated with?
Constipation and bowel cancer
How does a high fibre diet reduce cholesterol?
Cholesterol is used to release bile salts and fibre sequesters these salts so they pass out in faeces. With more fibre, more cholesterol is used up so there is less in the blood
What are dietary reference values (DRVs)?
Series of estimates of the amount of energy and nutrients needed by different groups of healthy UK population
What are the different DRVs? (4)
1) Reference Nutrient Intake (RNI)
2) Estimated Average Requirement (EAR)
3) Lower Reference Nutrient Intake (LRNI)
4) Safe intake
What is RNI used for?
Protein, vitamins and minerals
What is EAR used for?
Energy
When is Safe Intake used?
When there is insufficient data
Energy requirements vary between individuals depending on which factors?
Age
Sex
Body composition
Physical activity
What is daily energy expenditure the sum of?
Basal metabolic rate (BMR)
Diet-induced thermogenesis (DIT)
Physical activity level (PAL)
What does the BMR maintain?
Body temperature
Ion transport across membranes
Biochemical reactions
Function of organs
What is the short term store of energy rich molecules in muscle?
Creatine phosphate
What is obesity?
Excessive fat accumulation in adipose tissue which impairs health
Obesity is associated with an increased risk of which conditions?
Cancers
Cardiovascular disease
Type 2 diabetes
What is the equation to calculate BMI?
Weight (kg)/height^2 (m^2)
What are the units of BMI?
Kg/m^2
A BMI of under which value is classed as:
1) underweight
2) desirable weight
3) overweight
4) obese
5) severely obese
1) <18.5
2) 18.5-24.9
3) 25-29.9
4) 30-34.9
5) >35
A greater proportion of fat in the upper body compared with that on the hips is associated with an increased risk of which conditions?
Insulin resistance Hyperinsulinism Type 2 diabetes Hypertension Hyperlipidaemia Stroke Premature death
Which condition can a low protein diet result in?
Kwashiorkor
What can low protein intake result in?
Insufficient blood protein synthesis leading to decreased plasma oncotic pressure and oedema
