Obesity Management

Question 1

What is the definition of obesity?

Answer 1

chronic, life-threatening disease

An excessive accumulation of body fat sufficient to im0pair health

Question 2

What are some things obesity can lead to? (5)

Answer 2

Heart disease
Stroke
Sleep apnoea
Cancer
Liver disease

Question 3

What causes obesity?

Answer 3

Individual lifestyle choice
Society: Abundant, cheap, palatable food No need for physical activity at home or work
Genetic factors

Question 4

What is energy balance?

Answer 4

“State in which energy intake, in the form of food and /or drinks, matches the energy expended”

Question 5

What is positive energy balance? (2)

Answer 5

Energy in is greater than energy out Resulting in weight gain

Question 6

What is negative energy balance? (2)

Answer 6

Energy in is less than energy out

Resulting in weight loss

Question 7

What are three components of daily energy expenditure?

Answer 7

Thermic effect of feeding
Energy expenditure of physical activity
Resting energy expenditure

Question 8

What are the factors that can influence Resting energy expenditure (REE)? (8)

Answer 8

1. Body composition
2. Gender
3. Age
4. Height, Weight
5. Hormones e.g. Thyroid
6. Body temp
7. Pregnancy
8. Fasting/Malnutrition

Question 9

What does the Barker hypothesis state?

Answer 9

“Adverse environments in foetal life and early childhood establish increased risk of disease in adult life”

Question 10

When does maladaptation occur?

Answer 10

When there is a Mismatch of poor prenatal environment and rich postnatal environment

Question 11

What % of heritability of obesity?

Answer 11

40-60%

Question 12

What can genetic factors influence?

Answer 12

body size and shape
body fat distribution
metabolic rate
brain chemistry

Question 13

What is thrift metabolism?

Answer 13

Cycle of feast and famine

Thrifty metabolism gene allows for increase fat storage to protect against famine

Question 14

What is the % of a child becoming obese if parent/s are?

Answer 14

No obese parents = 10%
1 obese parents = 40%
2 obese parents = 80%

Question 15

What is the obesity gene?

Answer 15

FTO - shows fatty foods more tempting and altered levels of the hunger hormone, ghrelin

Question 16

What is the FOOD4ME study?

Answer 16

A study that aims to:

mimic an internet-delivered personalised nutrition service, with blood analysis and DNA home testing kits

Question 17

What are the two feedback signals for energy homeostasis?

Answer 17

Short term: operates meal to meal basis, determine amount of food ingested in single meal

Long term: works over weeks/years to regulate energy intake & expenditure
Modulated by adipose tissue mass; major mediators are leptin and insulin

Question 18

What is Grelin? and where is it released from?

Answer 18

A hormone which increases food intake

Released from GI tract - gastric mucosa

Question 19

What is Leptin? and where is it released from?

Answer 19

Hormone regulates long term body weight rather than short term appetite
Released from Adipose tissue

Question 20

When does Leptin peak at? Where does it act?

Answer 20

Diurnal variation: peak at night

Acts in the CNS to suppress food intake

Question 21

Which neurons does Ghrelin stimulate?

Answer 21

Stimulates NPY neurons

Question 22

Which disease has high levels of Ghrelin?

Answer 22

Prader-Willi syndrome - rare condition. It’s caused by a genetic defect on chromosome number 15, which happens purely by chance

Question 23

What hormones does the adipose tissue excrete and what do they do? (6)

Answer 23

Aromatase, which is involved in sex hormone metabolism.

TNF alpha, IL-6 and leptin, which are collectively termed ‘cytokines’ and are involved in sending messages between cells.

Plasminogen activator inhibitor-1, which is involved in the clotting of blood.

Angiotensin, which is involved in blood pressure control.

Adiponectin, which improves the body’s sensitivity to insulin and so helps to protect against developing type 2 diabetes

Lipoprotein lipase and apolipoprotein E, which are involved in storage and metabolism of fat to release energy.

Question 24

What are the mechanisms by which adipose tissue may influence cancer risk of obesity and cancer?

Answer 24

Production of sex steroid hormones

Effects on insulin sensitivity and production of insulin-like growth factors

Actions on other hormones in adipose tissue (e.g., leptin, adiponectin)

*Increases in oxidative stress and chronic low-grade inflammation that affect the body’s immune response

Question 25

What are the THREE treatment options for obesity? give examples of each

Answer 25

Lifestyle modification e.g. behaviour change

Medical treatment e.g. Orlistat, Incretin mimetics (GLP-1 Agonists)

Surgical treatment e.g.
Gastric band (Lap band)
Gastric bypass
Vertical Sleeve gastrectomy

Question 26

What are the benefits of a 10% weight loss?

Answer 26

Mortality: 20-25% fall in overall
30-40% in diabetes related deaths
40-50% fall in obesity-related cancer deaths

Diabtetes: Up to 50% fall in fasting blood glucose
Reduces risk of developing diabetes by over 50%

Lipids:Fall of 10% total cholesterol, 15% LDL and 30% TG; Increase of 8% HDL

BP:10 mmHg fall in diastolic and systolic pressures

Question 27

How does Orlistat work? (120mg)

Answer 27

Reduces fat absorption
Eating fat causes anal leakage
Can cause substantial weight loss

Question 28

How does Phentermine work?

Answer 28

Suppress appetite

May help but results in dry mouth, nausea and constipation.

Question 29

What is sleep apnoea?

Answer 29

Intermittent cessation of breathing during sleep due to the collapse of the pharyngeal airway, resulting in multiple apnoeic or hypopnoeic events