10. Obesity Flashcards
Define ‘obesity’
Abnormal or excessive fat accumulation sufficient to adversely affect health and reduce life expectancy
How is the BMI calculated?
Weight (kg)/height (m squared)
What are the reasons for the recent increase in obesity levels in the UK?
Unhealthy food is much cheaper than their healthier counterparts e.g. fried chicken, sugar-sweetened beverages
Less physical exercise is being undertaken due to increased sedentary life style
Increased usage of medications - about 10-15% of these can result in weight issues e.g. beta blockers, allergy relievers, insulin
What are the genetic relations of obesity?
Obesity is a highly heritable trait compared to e.g. hypertension, autism
What is meant by the ‘thrifty gene’ hypothesis?
Idea proposed in 1960s
Idea that genes that predispose to obesity had a selective advantage in starving populations
SO the people that have these genes are more likely to become extremely obese rather than just slightly overweight, as others would become
What is meant by syndromic monogenic obesity?
Due to a single altered genes, people present with a range of symptoms, all of which include obesity
They often also include mental retardation, dysmorphic features and organ specific abnormalities
There are about 30 genes that can be altered in this way
What is meant by non-syndromic monogenic obesity?
Where a single gene disorder has a direct correlation with increased level of obesity rather than with other features
12 genes have currently been identified
What should you remember about adipose tissue?
Not just for storage of fat but is also an important endocrine organ
What is the function of brown adipose tissue?
Main site of adaptive thermogenesis
Protection against obesity and metabolic diseases e.g. type 2 diabetes and dyslipidaemia
What else relates to health problems rather than just the quantity of fat stored?
Where the fat is stored
Apple shape - have more visceral fat and have a higher risk of weight-related health issues
Pear shape - less visceral fat and so have a lower risk of weight-related health issues
What is obesity a major risk factor for?
Cardiovascular diseases
Pulmonary diseases e.g. sleep apnoea
Metabolic diseases e.g. diabetes and dyslipidaemia
Osteoarticular diseases - bones are carrying the increased weight
Several cancers
Psychiatric illnesses
Early onset type 2 diabetes
What are the treatments for obesity?
NUMBER ONE TREATMENT - LIFESTYLE MODIFICATIONS AND PREVENTION:
Changes in diet and increased level of exercise
Drug treatments
The main prescribed drug is ‘Orlistat’ - reduces the amount of fat absorbed from food eaten by acting as a lipase inhibitor
Surgery:
Must have first undertaken a weight management course in which they are taught about diet and nutrition, fitness and exercise
Performed in people with morbid obesity (>40 BMI) OR with BMI >35 and obesity-related complications once conventional medical treatments have failed
What different surgical procedures can be used to treat obesity?
Restrictive procedures:
Restrict the ability to eat e.g. adjustable gastric banding
Melabsorptive procedures:
Reduced ability to absorb nutrients BUT this can result in nutrient deficiencies and malnutrition
