Weight Management

Question 1

What is the BMI equation?

Answer 1

BMI = weight (kg) / [height x height (m)]

Question 2

How many calories are there in 1g of carbohydrate, protein and fat?

Answer 2

Carbohydrate / protein = 4 calories
Fat = 9 calories

Question 3

How does Optifast work?

Answer 3

12 weeks, 5:2 intermittent VLCD (very low calorie diet)

5 days of normal eating, 2 days of 800kcal/day meal replacement shakes

Question 4

What are the BMIs for underweight, normal, overweight and obese? (based on Asian standards)

Answer 4

Underweight <18.5
Normal 18.5-22.9
Overweight: 23-27.4
Obese ≥27.5

(higher percentage of fat in Asians)

Question 5

How to diagnose obesity?

Answer 5

BMI, waist circumference

Question 6

What is a normal waist circumference and waist hip ratio for males and females?

Answer 6

Males: waist circumference ≤90cm or waist hip ratio ≤0.9

Females: waist circumference ≤80cm or waist hip ratio ≤0.85

Question 7

What medications do people misuse for obesity?

Answer 7

Laxatives (induce diarrhoea)
Diuretics (induce diuresis)
Thyroxine (increase metabolic rate)

Question 8

How much weight should patients lose?

Answer 8

Aim to lose 0.5-1kg/week
Short term goal of 5-10% weight loss over 6 months

Question 9

What drugs (and class i.e. GSL) are used for obesity?

Answer 9

Orlistat (P-only, min age 18y)
Phentermine (POM)
Liraglutide (POM)

Question 10

How does Orlistat work?

Answer 10

Reversible inhibitor of gastric and pancreatic lipases -> block GI fat absorption

Question 11

Common side effects of Orlistat?

Answer 11

Abd cramps, flatulence, oily stools, faecal incontinence

Question 12

Dose of Orlistat? And administration

Answer 12

120mg up to TDS (max 360mg/day, up to 4 years)
take before or up to 1h after meals

Question 13

Should Orlistat be discontinued if treatment is not working?

Answer 13

Yes, stop after 12 weeks if patient cannot lose ≥5% of initial body weight

Question 14

How does phentermine work?

Answer 14

Centrally acting appetite suppressant

Question 15

Minimum age of phentermine and liraglutide?

Answer 15

12 years old

Question 16

Dose of phentermine? and administration

Answer 16

Initial: 30mg OD
Maintenance: 15-30mg in one to two divided doses (give 2nd dose 10-14h before bed)
Adm: 30min-1h before breakfast, swallow whole

Question 17

How long should phentermine be used for?

Answer 17

12 weeks, then drug-free period for 4-12 weeks (max 6-12 months)

Question 18

Common side effects of phentermine?

Answer 18

tachycardia, palpitations, elevated BP, N/V, dry mouth, abd pain, insomnia, restlessness, nervousness

Question 19

Rare side effects of phentermine?

Answer 19

psychotic episodes, hallucinations, euphoria

Question 20

How long should liraglutide be used for?

Answer 20

12 weeks, stop after that if patient has not lost ≥5% of their body weight

Question 21

Side effects of liraglutide?

Answer 21

Common: HA, N/V/D/C
Rare: pancreatitis, thyroid disease, thyroid C-cell tumour