2. Nutrition, Body Weight and Homeostasis

Question 1

Define energy.

Answer 1

The capacity to work.

Question 2

Define 1Kcal.

Answer 2

The amount of energy needed to raise temperature of one kilo gram of water by one degree Celsius.

Question 3

What is the conversion rate of Kcal and kJ?

Answer 3

1 Kcal = 4.2 kJ.

Question 4

What is intake of carbohydrate used for?

Answer 4

For supplying energy.

Question 5

What is intake of protein used for?

Answer 5

Energy and amino acids.

Question 6

What is intake of fat used for?

Answer 6

Energy and essential fatty acids.

Question 7

What is intake of water used for?

Answer 7

Hydration.

Question 8

What is intake of fibre used for?

Answer 8

Normal GI function.

Question 9

What are the main dietary carbohydrates?

Answer 9

Starch (carbohydrate storage molecule in plants), sucrose (table sugar), lactose (milk sugar), fructose (from fruit), glucose (sugar in human blood).

Question 10

How many different amino acids are used for protein synthesis?

Answer 10

20.

Question 11

How many essential amino acids, that can’t be synthesis so must be obtained from diet, are there?

Answer 11

9.

Question 12

What are the nine essential amino acids?

Answer 12

Isoleucine
Lysine
Threonine
Histidine
Leucine
Methionine
Phenylalanine
Tryptophan 
Valine

Question 13

Why does fat produce much more energy when oxidised?

Answer 13

It contains less oxygen than carbohydrates or proteins.

Question 14

Which vitamins are fat-soluble?

Answer 14

A, D, E and K.

Question 15

What are minerals used for in the body?

Answer 15

Establishing ion gradients across membranes and maintaining water balance.

Question 16

Why are vitamins needed in the body?

Answer 16

A deficiency of them lead to diseases.

Question 17

What can a low fibre intake lead to?

Answer 17

Constipation and bowel cancer.

Question 18

What can a high fibre do?

Answer 18

Reduce cholesterol and diabetes risk.

Question 19

What are dietary reference values (DRV)?

Answer 19

A series of estimates of the amount of energy and nutrients needed by different groups of healthy UK population.

Question 20

What are nutrient requirements dependent on?

Answer 20

Age, gender and level of physical activity.

Question 21

How are estimated average requirements (used for energy) estimated?

Answer 21

Requirement for 50% of the group, so half the group will need more than what the EAR suggests.

Question 22

How are reference nutrient intakes (for mineral) estimated?

Answer 22

The level where the need of 97.5% are met, many in the group will need less.

Question 23

How are lower reference nutrient intakes (LRNI) estimated?

Answer 23

The amount that is enough for only a small number of people (2.5%) so the majority need more than this.

Question 24

What causes variation in the energy requirements of people?

Answer 24

Age, sex, body composition and physical activity.

Question 25

What is daily energy expenditure the sum of?

Answer 25

Basal metabolic rate, diet-induced thermogenesis (energy required to process food) and physical activity level.

Question 26

What is the basal metabolic rate?

Answer 26

The energy needed to maintain resting activities of the body, like maintenance of cells (ion transport and biochemical reactions), function of organs and maintaining body temperature.

Question 27

What factors affect BMR?

Answer 27

Body size, gender, environmental temperature, endocrine status and body temperature.

Question 28

What is energy used for during physical activity?

Answer 28

Contraction of skeletal muscle, cardiac muscle and respiratory muscle.

Question 29

What is the order that the following stores of energy are used? Muscle protein, muscle, carbohydrate and adipose.

Answer 29

Muscle, carbohydrate stores, adipose, muscle protein.

Question 30

What is the most noticeable difference between a 70kg and 100kg man in terms of body composition?

Answer 30

Lipid stores, approximately 12kg for the 70kg man but 40kg for the 100kg man.

Question 31

Define obesity.

Answer 31

Excessive fat accumulation in adipose tissue that impairs health. BMI of over 30 kg/m2.

Question 32

What is the formula for calculating BMI?

Answer 32

BMI = weight (kg) / height2 (m2)

Question 33

What is an alternative measurement of weight classification to BMI?

Answer 33

Hip to waist ratio.

Question 34

Name two complications that upper body fat increases the risk of.

Answer 34

Insulin resistance/type II diabetes, hyperinsulinism, hypertension, hyperlipidaemia, stroke or premature death.

Question 35

What causes Kwashiorkor?

Answer 35

Low protein intake from malnutrition so resulting in insufficient blood protein synthesis and decreased plasma inciting pressure, which leads to oedema.

Question 36

What are the 6 main functions of blood?

Answer 36

Transport (of oxygen, nutrients, waste products and hormones), coagulation, immune functions, regulating body pH, regulating body temperature and hydraulic functions.

Question 37

Define homeostasis.

Answer 37

Mechanisms that counteract changes in the internal environment to maintain a dynamic equilibrium.

Question 38

What is the general outline of a homeostatic response?

Answer 38

Receptor detects change, control centre sends signal to counteract change, effectors bring about the desired change, negative feedback corrects the deviation.

Question 39

How are blood glucose levels maintained after eating?

Answer 39

Pancreas secretes insulin, insulting stimulates liver to take up glucose to store as glycogen and tissues take up glucose, plasma glucose levels decline back to normal.

Question 40

How are blood glucose levels maintained in a fasted state?

Answer 40

Pancreas releases glucagon, glucagon stimulates liver to break down glycogen and real ease glucose into the blood, plasma glucose levels rise back to normal.

Question 41

Explain the difference between catabolic and anabolic processes.

Answer 41

Catabolic processes break down molecules to release energy in the form of reducing power but anabolic processes use energy and raw material to make larger molecules for growth and maintenance.