Physiology of feeding and satiety - Week 1

Question 1

How is BMI calculated?

Answer 1

Weight (kg) / (Height in cm)^2

Question 2

What is the thin/normal BMI range?

Answer 2

Up to 25.0

Question 3

A BMI of 25.0-30.0 suggests….

Answer 3

Overweight

Question 4

What BMI range suggests obesity?

Answer 4

30-40

Question 5

What BMI range suggests morbid obesity?

Answer 5

> 40

Question 6

What are the 2 major factors influencing obesity?

Answer 6

Genetics & environment

Question 7

What kind of environment causes obesity?

Answer 7

Western diet

Question 8

Name 5 conditions which can be caused by obesity.

Answer 8

Type 2 Diabetes, High BP, heart attack, colon cancer, osteoarthritis

Question 9

Which type of diabetes is on the rise?

Answer 9

Type 2 Diabetes Mellitus

Question 10

Why do we need fat?

Answer 10

Energy storage
Prevention of starvation
Energy buffer during prolonged illness

Question 11

Why is it difficult to lose weight once you’ve gained it?

Answer 11

Brain views new weight as normal & diet as a threat to survival

Question 12

Where is the site of integration of feeding behaviour?

Answer 12

Hypothalmus

Question 13

Which change in the brain causes obesity?

Answer 13

lesioning ventromedial hypothalamus

Question 14

Which change in the brain causes leanness?

Answer 14

lesioning lateral hypothalamus

Question 15

What is meant by satiation?

Answer 15

sensation of fullness generated during a meal

Question 16

What is meant by satiety?

Answer 16

period of time between termination of one meal and the initiation of next

Question 17

What is meant by adiposity?

Answer 17

the state of being obese

Question 18

What are the 3 main controls of weight?

Answer 18

Satiety signalling, Adiposity negative feedback signalling, Food reward

Question 19

Which signals limit meal size?

Answer 19

Satiation signals

Question 20

Name 5 satiation signals.

Answer 20

Cholecystokinin (CCK), Peptide YY, Glucagon-like peptide 1, Oxyntomodulin (OXM), Obestatin

Question 21

Name a hunger signal

Answer 21

Ghrelin

Question 22

What is the role of Ghrelin?

Answer 22

Peripheral ghrelin stimulates food intake (Hypo) and decreases fat utilization

Question 23

Which two hormones report fat status to the brain?

Answer 23

Leptin & Insulin

Question 24

When may leptin/insulin malfunction?

Answer 24

Obesity

Question 25

Leptin is which type of hormone?

Answer 25

PLEIOTROPIC

Question 26

Give some uses of leptin.

Answer 26

Food intake/energy expenditure/fat deposition
Peripheral glucose homeostasis/insulin sensitivity
Maintenance of immune system
Maintenance of reproductive system
Angiogenesis
Tumourigenesis
Bone formation

Question 27

What is the effect of intracerebroventricular (icv) insulin on food intake?

Answer 27

Decreases food intake

Question 28

What is meant by food reward?

Answer 28

Activates reward pathway - releases Dopamine

Question 29

What are leptin levels like in the majority of obese people?

Answer 29

High due to high levels of adipose - leptin resistance likely

Question 30

What is the over-the-counter drug for obesity?

Answer 30

Orlistat/Xenical/Alli

Question 31

How does Orlistat work?

Answer 31

Inhibits pancreatic lipase decreasing triglyceride absorption
Reduces efficiency of fat absorption (~30%) in small intestine

Question 32

Which drug has recently been approved for treating obesity?

Answer 32

Contrave/Mysimba

Question 33

How does Mysimba work?

Answer 33

Combination of bupropion (dopamine re-uptake inhibitor) + naltrexone (opioid antagonist).

Question 34

Give an example of a drug for obesity which will be coming onto the market.

Answer 34

Liraglutide (Saxenda)

Question 35

How does Liraglutide (Saxenda) work?

Answer 35

Glucagon-like peptide 1 receptor agonist

Question 36

What is the most effective method for treating obesity?

Answer 36

Bariatric surgery such as gastric by-pass surgery

Question 37

What is meant by Adaptive Thermogenesis?

Answer 37

Thermogenic adipocytes produce energy as heat (brown adipose tissue)