AS Lecture 16 - Obesity Flashcards
What is the difference in energy balance in normal weight and obese people?
In steady state: energy in = energy out Obese/overweight has increased total energy ependiture
What is the difference between the western diet and ideal diet for protein, fat and carbohydrate?
What should energy be spent on and how much on each component?
What is the definition of obesity?
Weight, in terms of morbidity/mortality, BMI: 25-30 kg/m2 overweight and >30kg/m2 is obese, waist to hip ration-> the metabolic syndrome
What is the metabolic syndrome?
What are the waist circumferences for males and females that lead to increased and major risk?
Increased risk: M>94, F>80 Major risk: M>102, F>88
What are the 7 causes of obesity?
Energy intake, energy usage, genes, brain, endocrinology, behaviour, culture
What are some reasons as to why energy intake could cause obesity?
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
What are some reasons to explain energy usage as a cause for obesity?
Big reduction in energy expenditure over recent years
What are some reasons to explain genes as a cause for obesity?
Most obesity isn’t monogenic -> amount and site of weight gain is partly genetic
What gene was found in diabetics as an obesity gene?
FTO gene variant which means you are 1.67 times more likely to be obese, 3kg heavier
What is the energy homeostasis cycle?
What are some reasons to explain brain and endocrinology as a cause for obesity?
Important physical role in postprandial satiety and represent therapeutic targets
What are some reasons to explain behaviour and culture as a cause for obesity?
Individual behaviour and societal changes have contributed to obesity
What are some medical complications of obesity? FITB
What are the 3 approaches to obesity management?
Lifestyle diet and exercise, pharmacological, bariatric surgery
What are the benefits of losing 10kg from 100kg?
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%
What are some future medical therapies (pharmacological)?
Victoza, Saxenda, belviq, qsymia, contrave, oral GLP-1
What are the type of bariatric surgery procedures?
Adjustable band, Excised sleeve gastrectomy, gastric bypass
What is the mechanism of improved glycaemic control after bariatric surgery?
Occurs immediately after gastric bypass, changes in insulin resistance/secretion, changes in gut microbiota and changes in bile salt secretion
What are the health benefits of bariatric surgery?
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
What is the current criteria for bariatric surgery?
BMI >40kg/m2 with no comorbidities BMI >35kg/m2 with comorbidities BMI 30-34.9kg/m2 with a short duration of T2DM
What are the economic benefits of bariatric surgery?
Gain if 25% had surgery within 3yrs would be £1.3billion
What is the duodenal jejunal sleeve?
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
