C3. Physical Activity and Obesity Flashcards
What is obesity and how is it measured?
It is an excess of body fat, but in reality it is determined using indirect measurements of body, for example body fat index, BMI, and waist circumference
What is BMI? Give an example
BMI is a measurement of body fat, calculated by dividing weight in kilograms by height in meters squared –> indirect assessment of body fat percentage (kg/m^2)
ex. A BMI between 18.5 and 25 is normal (but for who lol?)
Limitations of BMI
Values can often be misleading - bodybuilders, weightlifters, large muscles
Childhood obesity –> associated with social stigmatisation and bullying (this raises ethical issue around the routine)
What is another type of assessment of body fat percentage + limitations?
Magnetic resonance imaging (MRI) - can be costly and time consuming
What are the major health consequences of obesity?
- Cardiovascular disease and hypertension
- type 2 diabetes
- osteoarthritis
Discuss the concept of energy balance
Energy balance is affected mainly by food intake, resting metabolic rate and physical activity (balance occurs when input=output) it is determined by energy intake and energy
What does the energy expenditure look like?
- energy intake > energy expenditure = weight gain
- energy intake < energy expenditure = weight loss
- energy intake = energy expenditure = stable body weight
Outline how chemical signals arising from the gut and from the adipose tissue affect appetite regulation
- Hormones are produced by the stomach and small intestine after eating and by adipose tissue (leptin) These pass to an appetite control centre in the brain that regulates feelings of hunger and satiety
- regulate appetite GHRELIN, LEPTIN (suppresses appetite, obese people deficient in this = always hungry)
- exercise helps to reduce both fat underneath the skin and the fat within the abdomen
