Obesity Flashcards
Describe the energy balance.
There is a balance between energy input and energy expenditure. Obese and overweight people have net energy input.
Increase intake
Decrease expenditure
What makes up the majority of energy expenditure?
REE - resting energy expenditure - AKA basal metabolic rate
How does REE change with weight loss?
As you lose weight, REE decreases so it becomes more and more difficult to lose more weight
How can obesity be defined?
Based on weight
BMI (weight/height^2) - this varies depending on ethnicity
What is another measure of obesity that can be used to determine risk of metabolic syndrome?
Waist: hip circumference
A high value indicates increased risk of metabolic syndrome
What are the five components of metabolic syndrome?
Waist: hip circumference Hypertension Fasting blood glucose Microalbumin + insulin resistance Low HDL
What waist circumferences give a major risk of CHD in men and women?
Men - >102
Women - >88
What polymorphism is associated with increased risk of obesity?
FTO (fat mass and obesity-associated gene)
How do you measure waist circumference and when it is difficult to measure this?
Mid point between the lowest rib and ileac crest.
~1 cm above navel
Accuracy difficult if BMI>35
Describe the effect of leptin on regulating energy intake.
Leptin is produced in the adipocytes and communicates with the hypothalamus and lets it know how much fat is stored in the adipocytes thus controlling feeding.
Describe the effect of insulin on adipocytes.
Promotes the storage of fatty acids in the adipocytes.
What is Ghrelin?
Hunger hormone - when you’re hungry, the Ghrelin levels increase and tell the hypothalamus that you need to eat
Energy expenditure and satiety will DECREASE
What is PYY?
Fullness hormone - this is released after a big meal
State some complications of obesity.
Hypertension T2DM Osteoarthritis Cancer Cardiovascular disease CIRRHOSIS
What is the only licenced obesity medication in the UK?
Orlistat
