AS Lecture 16 - Obesity

Question 1

What is the difference in energy balance in normal weight and obese people?

Answer 1

In steady state: energy in = energy out Obese/overweight has increased total energy ependiture

Question 2

What is the difference between the western diet and ideal diet for protein, fat and carbohydrate?

Answer 2

Question 3

What should energy be spent on and how much on each component?

Answer 3

Question 4

What is the definition of obesity?

Answer 4

Weight, in terms of morbidity/mortality, BMI: 25-30 kg/m2 overweight and >30kg/m2 is obese, waist to hip ration-> the metabolic syndrome

Question 5

What is the metabolic syndrome?

Answer 5

Question 6

What are the waist circumferences for males and females that lead to increased and major risk?

Answer 6

Increased risk: M>94, F>80 Major risk: M>102, F>88

Question 7

What are the 7 causes of obesity?

Answer 7

Energy intake, energy usage, genes, brain, endocrinology, behaviour, culture

Question 8

What are some reasons as to why energy intake could cause obesity?

Answer 8

Increase in fast food outlets, diet composition and weight gain, satiety complex endocrine regulation (don’t feel as full after fatty load compared to protein load)

Little ability to store protein and CHO, autoregulation following fat ingestion difficult

Question 9

What are some reasons to explain energy usage as a cause for obesity?

Answer 9

Big reduction in energy expenditure over recent years

Question 10

What are some reasons to explain genes as a cause for obesity?

Answer 10

Most obesity isn’t monogenic -> amount and site of weight gain is partly genetic

Question 11

What gene was found in diabetics as an obesity gene?

Answer 11

FTO gene variant which means you are 1.67 times more likely to be obese, 3kg heavier

Question 12

What is the energy homeostasis cycle?

Answer 12

Question 13

What are some reasons to explain brain and endocrinology as a cause for obesity?

Answer 13

Important physical role in postprandial satiety and represent therapeutic targets

Question 14

What are some reasons to explain behaviour and culture as a cause for obesity?

Answer 14

Individual behaviour and societal changes have contributed to obesity

Question 15

What are some medical complications of obesity? FITB

Answer 15

Question 16

What are the 3 approaches to obesity management?

Answer 16

Lifestyle diet and exercise, pharmacological, bariatric surgery

Question 17

What are the benefits of losing 10kg from 100kg?

Answer 17

Psychological benefit, PCOS, oesophagitis, CHD, osteoarthritis, liver function, preganacy, in diabetes, mortality decreased by 20%, 0.9mmHg decreased per Kg, risk of DM decreases by 40%, LDL decrease by 15%, HDL ^ by 8%

Question 18

What are some future medical therapies (pharmacological)?

Answer 18

Victoza, Saxenda, belviq, qsymia, contrave, oral GLP-1

Question 19

What are the type of bariatric surgery procedures?

Answer 19

Adjustable band, Excised sleeve gastrectomy, gastric bypass

Question 20

What is the mechanism of improved glycaemic control after bariatric surgery?

Answer 20

Occurs immediately after gastric bypass, changes in insulin resistance/secretion, changes in gut microbiota and changes in bile salt secretion

Question 21

What are the health benefits of bariatric surgery?

Answer 21

Resolution/improvement of T2DM/hypertension, improved lipid profile -> overall reduction in cardiac risk, resolution of obstructive sleep apnoea/PCOS (improved fertility), reduced cancer related deaths and mortality, regression of non-alcoholic fatty liver disease

Question 22

What is the current criteria for bariatric surgery?

Answer 22

BMI >40kg/m2 with no comorbidities BMI >35kg/m2 with comorbidities BMI 30-34.9kg/m2 with a short duration of T2DM

Question 23

What are the economic benefits of bariatric surgery?

Answer 23

Gain if 25% had surgery within 3yrs would be £1.3billion

Question 24

What is the duodenal jejunal sleeve?

Answer 24

It is a sleeve that is placed in the duodenum preventing bile secretion, which is less permanent that bariatric surgery and has been proven to work