4.6 Causes, Diagnosis and Treatment of Weight Disorders

Question 1

Why are early-life obesity intervention programs so important?

Answer 1

• Children who are overweight/obese as preschoolers are FIVE TIMES as likely to be obese adults
• The earlier we stop the obesity, the less it seems to persist through life

Question 2

Describe the benefits/limitations of BMI

Answer 2

Benefits: great for rough idea of weight and risk
Limitations: does not take into account body composition (bodybuilders, women have more fat, older people have more fat)

Question 3

Describe the benefits/limitations of tricep skinfold test

Answer 3

Benefits: cheap, fast, non-invasive

Drawbacks: does not account for visceral fat, variations of fat distribution (disease, genetics etc.)

Question 4

Describe the benefits/limitations of waist circumference test

Answer 4

Benefits: better indicator of disease risk than BMI, can be adjusted for gender/race

Limitations: does not differentiate between visceral/subcutaneous fat

Question 5

True or false: subcutaneous fat stores are notable for their ability to cause low-grade inflammation

Answer 5

• Not really
• This applies much more to visceral fat; another reason why obesity can cause insulin resistance

Question 6

True or false: exercise is the best known way to lose weight

Answer 6

• False
• It mostly comes down to diet (remember Alex Hormozi)

Question 7

List three physical activity goals to improve metabolic health

Answer 7

Goal 1: Reduce sedentary time
Goal 2: 30mins walking/day
Goal 3: 150mins moderate to vigorous activity per week

Question 8

Why is it a good idea to add fat and protein to carbohydrates?

Answer 8

• Slows gastric emptying
• Reduces insulin spikes

Question 9

How can we improve the healthfulness of our carbohydrate intake?

Answer 9

• Swap simple carbohydrates (e.g. white bread) for more complex carbohydartes (wholemeal bread)
• Slows glucose spike

Question 10

What are the healthier/less healthy types of fat to eat?

Answer 10

• Saturated/trans are less healthy
• Unsaturated are healthier

Question 11

Why are ultra-processed foods harmful? What is their effect on chronic disease risk?

Answer 11

• High in fat, salts, and sugar. Designed to override satiating mechanisms
• Causal in chronic disease

Question 12

What are the effects of leptin deficiency? How do we treat it?

Answer 12

• Loss of hunger reduction; severe obesity at young age
• Treated with metreleptin (synthetic leptin analogue)

Question 13

If the adipostatic mechanisms keep bodyweight within a range, why does ultraprocessed foot make everybody fat?

Answer 13

• High levels of fats, sugars, and salts override satiety mechanisms
• This alters the body’s bodyweight setpoint, leading to obesity

Question 14

What are two kinds of diets that have shown to be effective for weight loss?

Answer 14

• Time restriction
• Caloric restriction

Question 15

True or false: lifestyle interventions are 30% more effective than metformin for people with prediabetes

Answer 15

True. Get fucked, metformin companies.

Question 16

We have an obese patient. We’ve tried reduced energy diet, and pharmacotherapy, but we need more. What’s the next step?

Answer 16

Bariatric surgery.

Question 17

How does the body “defend” against weight loss?

Answer 17

• As you lose weight, your energy expenditure decreases
• In turn, this makes it harder to enter energy deficit, and lose more

(leptin also decreases, meaning more hunger)

Question 18

What are the long-term effects of weight loss on appetite? Why does this make sense if you’re a caveman?

Answer 18

• Appetite increases, and is sustained even after calorie deficit is gone
• If your environment is unstable, you need to get while the getting’s good

Question 19

Give two examples of drugs that can be used for pharmacological assistance of weight loss, and explain their mechs

Answer 19

• Orlistat (inhibits lipase enzymes)
• Semaglutide (GLP-1 agonist)

Question 20

True or false: bariatric surgery comprises a complete obesity management plan

Answer 20

• FALSE
• Must be done alongside lifestyle modifications

Question 21

For which patients do we consider bariatric surgery?

Answer 21

• All conservative measures have failed
• Severe weight-related complications

Question 22

How does gastric surgery address loss of satiety in obese patients?

Answer 22

• Limits portion size they can ingest (like in gastric sleeve)
• Interferes w/ calorie absorption
• Affects gut-brain satiety (stretch receptors triggered earlier)

Question 23

Who are patients assessed by before they meet a surgeon for possible bariatric surgery?

Answer 23

• Dietician
• Psychologist
• Endocrinologist

Question 24

List selection criteria for bariatric surgery

Answer 24

• BMI >40 (or >35 w/ severe medical issues)
• Past concerted weight loss attempts
• Age 16-65
• No alcohol/drug dependency
• Willing to commit to long term modification

Question 25

Up until ~10 years ago, what was the most common bariatric surgery? How did it work?

Answer 25

• Laparoscopic banding
• Collar placed around fundus of stomach
• Attached to subcutaneous port
• Fill port w/ saline to adjust collar size (and therefore restriction of food intake/satiety)

Question 26

What are some complications of laparoscopic band stomach surgery?

Answer 26

• Dissolving band
• Slipping band
• Tubing issues

Question 27

What is the most common bariatric surgery? How does it work anatomically?

Answer 27

• Gastric sleeving
• Greater curvature of the stomach is removed, only 15% of normal volume remains

Question 28

Gastric sleeving/bypass complications

Answer 28

• Sleeve re-expansion (for sleeving)
• Leakage
• Stenosis
• Reflux

Question 29

What is the most effective form of bariatric surgery? How does it work?

Answer 29

• Gastric bypass
• Small pouch in distal oesophagus
• Connects directly to jejunum