Nutrition, Weight, Diet Flashcards
What is a catabolic process?
Breaking down molecules to release energy
What is an anabolic process?
Using energy and raw materials to make larger molecules
What processes require energy? (4)
- ion transport
- muscle contraction
- biosynthesis
- thermogenesis (heat production)
What is excess ‘fuel’ stored as? (2)
- fat in adipose tissue
- glycogen in liver and muscle cells
What is biosynthesis?
Synthesis of cellular components
What is a exergonic reaction?
Energy released > energy input
Negative GFE
What is the opposite of exergonic?
Endergonic
What does isothermal mean?
Temperature remains constant
How is energy release from ATP?
Oxidation reaction
Phosphoidiester bond hydrolysed
What is BMR?
How do you calculate it?
Energy required to maintain life
100 x weight (kg)
What is the BMR controlled by?
Thyroid hormones
Why is the BMR lower for women?
They have more adipose tissue
Which is less metabolically active than lean muscle tissue
What causes BMR to be higher? (2)
Hyperthyroidism
Pregnancy and lactation
What requires a constant supply of glucose?
The brain
Red blood cells
Why do you not need to consume glucose?
- can make it through gluconeogenesis
- synthesised from galactose and fructose
Why are fats important in the diet? (3)
- high energy yield - can eat less
- required for the absorption of fat soluble vitamins
- provide essential fatty acids
What is 1Kcal?
Amount of energy needed to raise the temp on 1kg of water by one degree celcius
Give an example of a mono, di and polysaccharide
Glucose
Sucrose
Starch
What are three polymers of glucose?
Starch
Glycogen
Cellulose
What are essential amino acids?
Cannot be synthesised
Must be obtained from the diet
What is the best protein source and why?
Animal origin
Contain all essential amino acids
Comparison of fats with carbohydrates and proteins
Explain why
Require more energy when oxidised
Less oxygen
Why are electrolytes required?
- Establish ion gradients across memebranes
- Maintain water balance
What are iron, calcium and phosphorus used for?
Iron - component of haemoglobin
Calcium - signalling molecule, structure of bones and teeth
Phosphorus - structure of bones and teeth
What are the components of IV fluid?
Na+, K+, Cl- 1mmol/kg/day
Water 30ml/kg/day
What is special about fibre?
Cannot be broken down by human digestive enzymes
Give three examples of fibre
Cellulose
Pectin
Lignin
Three benefits of a high fire diet
- essential for GI tract
- reduced cholesterol
- lowered risk of diabetes
A low fibre diet is associated with what two things?
Constipation
Bowel cancer
What effects the nutrient requirements?
Age
Gender
Level of physical activity
X
What are nutritional requirements only useful for
Assessing requirements for groups - like gender and age
How much water are you recommend to consume per day
6-8 glasses
What are the calorie requirements for men and women
2500kcal
2000kcal
What factors make up the daily energy expenditure?
- BMR
- Physical activity level
- Diet induced thermogenesis (energy required to process food)
What factors effect the BMR?
- body size (SA)
- gender
- environmental temp (higher in the cold)
- endocrine status (thyroid levels)
- body temp (higher when hotter)
What muscles require energy during physical activity? (3)
Skeletal
Heart
Respiratory
Compare the time usage of muscle store, carbohydrate and adipose
Muscle - very short
Carbohydrate - immediate
Adipose - long term
What energy store is used in extreme conditions?
Muscle proteins
What causes fat to accumulate in adipose tissue?
Energy intake exceeding energy expenditure
What are three health effects of obesity?
Type 2 diabetes
Cardiovascular disease
Cancers
What is the calculation for BMI?
Weight (kg) / height^2 (m^2)
BMI for underweight
<18.5
BMI for desirable weight
18.5-24.9
BMI for overweight
25-29.9
BMI for obese
30-34.9
BMI for severely obese
> 35
What is a negative of using BMI?
Muscular individuals may be classified as obese
What is the alternative of BMI?
Waist:Hip
What risks are associated with greater proportion of fat in the upper body?
- insulin resistance
- type 2 diabetes
- hypertension
- hyperinsulinism - unregulated insulin secretion from the beta-cells
- premature death
What is the condition in which a young child has a protein deficiency and oedema?
Kwashiorkor
What is the condition in which a young child is protein deficient and emaciated?
Marasmus
What law summaries how an oedema forms?
Starlings law
How does refeeding syndrome work?
Rapid re-introduction of protein and food
Increase in blood sugar and insulin
Resulting in processes that require phosphate, magnesium and potassium
Resulting in an electrolyte imbalance
What causes a fatty liver?
Deficiency of essential amino acids
Liver is unable to synthesise sufficient lipoproteins
Lipids accumulate in the liver instead of being transported
What type of carbohydrate is glucose?
6 C
Monosaccharide
Why do fats have the most energy?
Contain less oxygen
Can yield more energy through oxidation reactions
What are the fat soluble vitamins?
A, D, E, K
What does it mean when someone is obese?
Excessive fat accumulation in adipose tissue
What causes marasmus?
Deficiency in all nutrients
Inadequate energy intake
Why do people with kwashiorkor have fatty livers?
No proteins to make enzymes or transporters
The fats can’t be moved or metabolised
Stored in the liver
What causes people with kwashiorkor to have oedemas?
Lack of protein intake
Can’t produce the plasma protein albumin
Lower oncotic pressure in the venous end of capillarities
Less fluid returns to blood vessels
What are the fat soluble vitamins?
A, D, E, K
How much food is consumed over the course of a year?
500kg
Rough daily energy expenditure for a male and female in KJ/day
12,000
9,500
