Lecture 36 - Coordinating Metabolism: Obesity

Question 1

What is obesity?

Answer 1

A chronic complex disease defined by excessive
fat deposits that can impair health.

Question 2

What does obesity influence?

Answer 2

Quality of living, such as sleeping, moving and
can have a negative impact on mental health.

Question 3

What does obesity increase the risk of?

Answer 3

Type 2 diabetes, heart disease,
stroke, impaired reproduction, liver and gall bladder disease,
respiratory disorders and certain cancers.

Question 4

New Zealand has the …. highest rate of adult obesity

Answer 4

Third

Question 5

What are some potential ways of achieving weight loss?

Answer 5

1. Reducing energy intake
2. Increasing activities
3. Increasing basal metabolism

Question 6

What are some ways of reducing energy intake?

Answer 6

Calorie restriction, low fat diet, low carb diet, blocking
fat absorption (Xenical).

Question 7

Why may diet weight loss be difficult to maintain?

Answer 7

The body resets to a lower basal metabolic rate

Question 8

What are ketogenic diets?

Answer 8

Diets restricted in carbs

Question 9

What do ketogenic diets promote?

Answer 9

The use of body fat and ketosis

Question 10

What do ketogenic diets do to insulin secretion?

Answer 10

Reduce it

Question 11

What do ketogenic diets do to your appetite?

Answer 11

Reduce appetite because

Question 12

What do keto diets based on saturated fats do?

Answer 12

Increase LDL levels

Question 13

What is Xenical?

Answer 13

a pancreatic lipase inhibitor that reduces fat absorption , was heavily marketed for weight loss.

Question 14

Why was Xenical not a favourable drug?

Answer 14

Due to moderate weight loss in trials and many side-effects
i.e. leakage, gas and fatty stools.

Question 15

What are ways that weight loss can be achieved?

Answer 15

• Increasing muscle mass because muscle is more metabolically active than
  fat and burns more ATP at rest.
• Uncouplers i.e. substances that uncouple OxPhos in the mitochondria, causing energy to be released as heat rather than generating ATP

Question 16

What are examples of things that increase basal metabolism?

Answer 16

• Dinitrophenol (DNP) and FCCP (cause hyperthermia and organ failurei.e. very toxic).
• BAM 15 (safer and showing promising results in preclinical studies).
• Uncoupling protein activators i.e. Mirabegron which targets UCP1 in brown adipose (associated with some heart problems).
• Thyroid hormones (also associated with some heart problems).

Question 17

What is Leptin and what does it do?

Answer 17

A hormone from adipose that signals to reduce appetite

Question 18

What does GLP-1 from the gut do?

Answer 18

Signals to reduce appetite

Question 19

What does Ghrelin from the stomach do?

Answer 19

Signals that the gut is empty and stimulates appetite

Question 20

What are GLP-1 agonists good for?

Answer 20

Off-label weight loss

Question 21

What is semaglutide?

Answer 21

A peptide similar to the endogenous hormone GLP-1

Question 22

What effects does GLP-1 have in terms of weight loss?

Answer 22

Decreases gastric emptying

Question 23

What does GLP-1 do in terms of diabetes?

Answer 23

• Less glucagon secretion
• more insulin secretion + biosynthesis
• More somatostatin secretion
• Less apoptosis

Question 24

What may leptin deficiency cause?

Answer 24

Overeating

Question 25

Does leptin resolve obesity?

Answer 25

Leptin doesn’t resolve obesity as it is leptin resistance that’s the problem

Question 26

Can leptin deficiency occur in humans?

Answer 26

Yes but it is very rare

Question 27

What are the competing paradigms of obesity pathogenesis?

Answer 27

Energy Balance model vs Carbohydrate-Insulin Model

Question 28

What is the primary dietary driver in the energy balance model?

Answer 28

Energy dense, ultra-processed foods high in portion size, fat, sugar but low in protein and fibre