Nutrition and Energy

Question 1

How do you calculate BMI?

Answer 1

Weight (kg) / Height^2 (m)

Question 2

What is classed as obese in terms of BMI?

Answer 2

BMI > 30

Question 3

What is classed as underweight in terms of BMI?

Answer 3

BMI < 18.5

Question 4

What is classes as overweight in terms of BMI?

Answer 4

BMI > 25

Question 5

What proportion of the energy requirement is taken up by the brain and liver?

Answer 5

40%

Question 6

Which fuels are used by the brain?

Answer 6

Glucose, ketone bodies

Question 7

Which fuels are used by the muscle?

Answer 7

Glucose, ketone bodies in starvation

Question 8

Which fuels are used by the liver?

Answer 8

Glucose, amino acids, fatty acids. Liver cannot use ketone bodies as it does not have the enzyme thiolase

Question 9

What does BMR mean?

Answer 9

Basal metabolic rate. Minimum amount of energy required to keep the body alive. Measured by O2 consumption. Measured in kcal expended/hr/m^2

Question 10

What are the functions of vitamin A? What are the sources? What does a deficiency in vitamin A lead to?

Answer 10

Functions: Cellular growth, process of vision, reproduction, embryonic development

Sources: oily fish, dairy

Deficiency leads to: night blindness, xerophthalmia (eye fails to produce tears), growth retardation

Question 11

What are the functions of vitamin C? What are the sources? What does a deficiency in vitamin C lead to?

Answer 11

Functions: Synthesis of collagen, neurotransmitters and carnitine

Sources: Citrus fruits, green leafy veg, potatoes

Deficiency: Weakness, bleeding gums, 50-100 days without vitamin C leads to scurvy

Question 12

What are the functions of vitamin B? What are the sources? What does a deficiency in vitamin B lead to?

Answer 12

Function: Cell metabolism and energy production

Sources: Vitamin B-12 is found in fish, poultry and eggs

Deficiency: Pernicious anaemia

Question 13

What are the functions of vitamin D? What are the sources? What does a deficiency in vitamin D lead to?

Answer 13

Function: Stimulates intestinal absorption of Ca2+ and phosphate

Sources: Vitamin D3 is derived from sunlight, vitamin D2 is derived from plants

Deficiency: Decreased intestinal Ca2+ absorption so decreased plasma Ca2+. Detected by receptors in parathyroid gland, resulting in release of parathyroid hormone. This causes Ca2+ and phosphate ions to move from bone into extracellular fluid - leading to decreased bone mass and osteoporosis.

Question 14

What are the functions of vitamin E? What are the sources? What does a deficiency in vitamin E lead to?

Answer 14

Functions: Antioxidant

Sources: Almonds, spinach

Deficiency: Weakness, muscle damage

Question 15

What are the functions of vitamin K? What are the sources? What does a deficiency in vitamin K lead to?

Answer 15

Functions: Essential for production of clotting factors

Sources: Green leafy veg, meat, eggs, fish

Deficiency: Increased risk of excessive bleeding due to decreased production of clotting factors

Question 16

What is malabsorption?

Answer 16

Inadequate absorption of nutrients from the intestines.

Question 17

Describe some causes of malabsorption.

Answer 17

1. Giardiasis: infection that causes villi to atrophy, reducing absorption capacity
2. Coeliac disease: autoimmune condition whereby gluten is partially degraded, triggering the immune system to attach the villi resulting in a loss of intestinal brush borer surface area
3. Cystic fibrosis: Caused by autosomal recessive mutation in epithelial channel - CFTR (cystic fibrosis transmembrane conductance regulator). As this channel is faulty, Cl- levels build up in gland cells, preventing HCO3- entry into the small intestine resulting in decreased digestion and absorption.