Obesity

Question 1

Define the term ‘obesity’.

Answer 1

abnormal or excessive accumulation of fat that presents a risk to health

BMI of 30+

30 -35 = obese class 1 
35- 40 obese class 2
40+ obese class 3 (morbidly obese)

Question 2

What are the 2 sites of fat distribution?

Answer 2

subcutaneous (under the skin)

visceral (around the organs)

Question 3

Which kind of fat distribution is most associated with poor health outcomes?

Answer 3

visceral fat

Question 4

Describe the 3 types of adipocyte (fat cell)

Answer 4

white adipocyte:

• contains mostly lipid droplet
• also contains mitochondria and nucleus

brown adipocyte:

• smaller lipid droplets
• many mitochondria and nucleus

beige adipocyte:

• slightly larger lipid droplets
• not as many mitochondria and nucleus

Question 5

What is the role of brown adipocytes in adipose tissue?

Answer 5

thermogenesis due to large number of mitochondria

Question 6

Describe the role of hyperplasia in rebound weight gain

Answer 6

hyperplasia is the increase in the reproduction rate of cells leading to an increase in the organ size

weight loss and then weight gain leads to metabolic mechanisms during the return to obesity that promote hyperplasia.

Question 7

Describe why multiple fat cells are created in obesity.

Answer 7

there is a threshold limit to the amount of lipid that an adipocyte can store and once that critical capacity has been reached, the only course is to increase the capacity by generating new adipocytes.

Question 8

What role does fat play in the body?

Answer 8

cell membrane integrity
component of the myelin sheath
boe marrow
neural tissue

Question 9

What type of organ is adipose tissue? Why?

Answer 9

Endocrine organ

it secretes thousands of hormones and cytokines (cell signalling molecules)

Question 10

What are adipokines?

Answer 10

type of cytokine produced by the adipose tissue that play functional roles in energy/metabolic status of the body, inflammation, obesity

Question 11

What is the difference between lean adipose tissue and obese adipose tissue?

Answer 11

lean adipose tissue has an equal proportion of anti-inflammatory and pro-inflammatory cytokines

obese adipose tissue has a greater proportion of pro-inflammatory cytokines

Question 12

How is obesity linked to the development of other chronic diseases?

Answer 12

Obesity is a chronic inflammatory disease, as obese adipose tissue is characterised by a greater number of pro-inflammatory cytokines than anti-inflammatory cytokines.

A greater proportion of pro-inflammatory molecules causes cellular stress and damage. This promotes the release of molecular markers such as:

• cytokines
• interleukins
• adhesion molecules

This leads to further inflammation.

Inflammation is linked to impaired organ/tissue function, such as insulin resistance, high blood pressure, and tumour cell proliferation. These impairments lead to chronic conditions such as type 2 diabetes, cancer, atherosclerosis and CVD.