Sustainable Weight Loss

Question 1

RYGB

Answer 1

Roux-en-Y bypass - small gastric pouch (15-30mL) on the lesser gastric curvature which is completely divided from the gastric remnant and then anastomoses to the jejunum, get the stomach secretions still

Question 2

Complication with the RYGB

Answer 2

30 days after the surgery - 4% of patients - bleeding, perforation or leakage - immediate surgical re-intervention

Question 3

What does RYGB treat? - 3

Answer 3

Not some of the aetiological factors of morbid obesity e.g. obesogenic environment
20-30% long term over 2 years of weight loss and maintenance, >50% of excess body weight
Improvement/remission of many obesity related comorbidities (hypertension, T2D, mellitus, obstructive sleep apnoea and musculoskeletal pain) - 40% of T2D go into remission within days/weeks

Question 4

What causes the reduced kcal intake after RYGB?

Answer 4

Significantly smaller meal sizes = reduced caloric content

Question 5

What’s a dominant contributing factor of reduced caloric intake.

Answer 5

Enhanced satiety

Question 6

Calorie count for post RYGB

Answer 6

Dramatic decrease - 600-700kcal in the first month, then rise to 1000-1800 during the first year.

Question 7

Changes in behaviour associated with eating after RYGB?

Answer 7

Reported in 1970s using structured interviews that suggested they reached satiety more quickly - common reason of lack of desire for food.

Question 8

RYGB and endogenous gut hormone responses

Answer 8

Elevated responses for Glucagon like peptide 1, peptide YY respond to mixed meals/oral glucose - may remain high for more than a decade

Question 9

Why do we think its more than GLP 1 that works after RYGN

Answer 9

Because enhanced GLP 1 signaling is not sufficient to reduce body weight so there should be multiple gut hormone that mediate the increased satiation

Question 10

Ghrelin and RYGB

Answer 10

Ghrelin deficiency b/c it usually increases after diet induced weight loss

Question 11

RYGN and neural responses - 2

Answer 11

Reduce hedonic behaviour associated with eating highly palatable and calorie dense foods compared to patients who ha
Selective decrease of reward value of a sweet and fat tastant, but not veggies.

Question 12

GYFB and total plasma build acids

Answer 12

Pournaras et al - elevated - partly responsible for anorexigenic hormone secretion

Question 13

What causes the the significant improvement of weight, inflammation and metabolic status after surgery?

Answer 13

Increased bacterial variety

Question 14

Gut microbiota from GYGB treated mice to non -operated germ free mice

Answer 14

Caused weight loss and reduced fat mass - altered microbial production of short chain fatty acids

Question 15

hedonic response to high calorie foods compared between RYGB and adjustable gastric banding

Answer 15

lower for RYGBs

Question 16

Thermogenesis after RYGB - 2

Answer 16

decreased basal metabolic rate but increased meal induced thermosgenesis

Question 17

RYGB and pancreatic exocrine function

Answer 17

impair it which could contribute to a small amt of fat malabsorption but probably too small to contribute to weight loss

Question 18

will RYGB result in calorie malabsorption?

Answer 18

not likely

Question 19

RYGB and unexplained chronic abdominal pain

Answer 19

10%

Question 20

Iron and RYGB

Answer 20

deficiency due to reduced acid production in the small stomach pouch

Question 21

B12 and RYGB

Answer 21

deficiency in 70%

Question 22

folic acid and RYGB

Answer 22

deficiency in 35%

Question 23

RYGB and hypocalcemia & 25 -hydroxy vit D

Answer 23

hypocalcemia up to 10 % and low serum 25-hydroxy vit D levels in up to half

Question 24

Major physiological changes that take place after RYGB

Answer 24

exaggerated release of satiety gut hormones with their central and peripheral effects on glycemia and food intake

Question 25

Understanding the mechanisms of RYGB will

Answer 25

speed up the development of more effective and safer surgical and non-surgical treatments for obesity.

Question 26

Is the challenge to lose weight?

Answer 26

no its to keep it off

Question 27

Do diff diets of macros work differently?

Answer 27

no - modest diff in weight loss and metabolic risk factors - little diff in weight and health outcomes in time frames longer than 6 months

Question 28

National Weight Control Registry looked at adults that have lost more than 13.6 kg of weight and kept it off for a year, tracking 10,000 people their strategies were - 3 +3

Answer 28

formal program 
98% diet 
94% PA 
regular meal patterns -
 prepare and eat at home 
portion control - limit intake of food and quantity - count calories and food diary 
weigh in daily

Question 29

Additional ways of keeping weight off - 12

Answer 29

decrease total energy intake 
decrease energy density 
increased dietary fibre
decrease fat intake from fast foods 
fewer sugar sweetened beverages 
low sugar and low fat foods 
decreased total alcohol intake 
increased water intake 
food diaries 
increased PA (lifestyle and planned)
breakfast everyday 
behavioural strategies - self monitor, food diary, weigh in, goal setting-fdbk

Question 30

diet consistency

Answer 30

maintaining same diet regimen across the week and year instead of having cheat days is also important

Question 31

PA and maintenance of weight loss

Answer 31

essential - less than 10% said they dont engage in PA - lifestyle and planned activities to balance the enery intake and expenditure

Question 32

how to best use a diet to keep your weight off

Answer 32

Take one that you will find easiest to adhere to long term

Question 33

How did the Twinkie diet work?

Answer 33

1800kcal cap, 2/3 came from junk food 
- decreased LDL 
- increased HDL 
- decreased body fat 
multivit everyday

Question 34

4 treatment options for overweight and obesity

Answer 34

Lifestyle management - diet and PA
Pharmacotheraphy - Liraglutide (GLP-1 agonist) and Orlistat (Xenical)
Metabolic/bariatric surgery - indications: BMI>40, or >35 with diabetes
Not doing anything

Question 35

What does Orlistat do?

Answer 35

inhibit the breakdown of fat

Question 36

3 types of bariatric surgery

Answer 36

Roux-en Y gastric bypass
Sleeve gastrectomy
Adjustable gastric band

Question 37

adjustable gastric band

Answer 37

if you filled the outside thing with saline you can adjust the opening and food wont go down as rapidly

Question 38

if you reverse the surgery what happens to your weight

Answer 38

Comes back up

Question 39

adverse effects of bariatric surgery - 6

Answer 39

post operational complications - 4% bleeding, perforations, leakage
mortality 0.1-2%, depending on surgery type
abdominal pain
vit b12, folate, and D deficiency - diff acids
calcium and iron deficiency
bone loss

Question 40

4 mechanisms of bariatric surgery

Answer 40

increased delivery of food into the midgut
altered appetite and gut satiety hormones
increased thermic effect of food (increased metabolic rate of small bowel)
may be some fat malabsorption

Question 41

7 altered appetite and gut satiety hormones

Answer 41

increase GLP1 and PYY for years - they dont have to wait for food to get down
ghrelin decreases
altered vagal signaling
altered bile acid signaling - enteroendocrine Lcells and Liver cells (metabolism and more satiety hormones)
modified gut microbiota composition and diversity
conditioned food avoidance due to dumping syndrome (glycemic issues)
reduced hedonic response to palatable food

Question 42

how many people got bariatric surgery in 2013/14?

Answer 42

6500, increase of 300%

Question 43

recidivism of weight management

Answer 43

reduced leisure time activity, dietary restraint, self weighing
increased energy intake from dietary fat and increased disinhibition

Question 44

is our biology broken?

Answer 44

no, we just need to learn to deal with it