15. Physical activity and CVD risk factors: Obesity

Question 1

what are the ways you can assess a person’s body composition?

Answer 1

Magnetic Resonance Imaging (MRI)
Dual-energy x-ray absorptiometry (DEXA)
Underwater weighting 
Sum of skinfolds
Waist circumference
Waist/hip ratio
BMI
Bioelectrical Impedance

Question 2

How do you categorise people as overweight or obese based on BMI

Answer 2

BMi = bodyweight(kg) divided by Height(m) squared
overweight = 25-29.9 BMI score
Obese = 30 and above

Question 3

What are the recent trends in the prevalence of obesity

Answer 3

In a study of 900 000 participants. For each 5kg/m^2 your BMI was on average associated with about 30% higher overall mortality.
At 40-45 BMI your survival is reduced by 8-10 years which is comparable with the effect of smoking.
There is a trend between the increase in obesity prevalence and an increase in energy intake.

Question 4

Discuss how our environment has become more obesogenic

Answer 4

• increase in cars
• increased tv viewing
• more measures of physical inactivity
• rise in obesity in the uk may not be us necessarily eating more but that we are finding ways to expend less energy.
• Decrease in manual labour
• Less NEAT (non-exercise physical activity)

Question 5

List the health risks associated with overweight and obesity

Answer 5

Increased overall mortality rates
Increase disease risks
Detrimental effects in existing heart, vascular and metabolic diseases
Adverse psychological effect

Question 6

Summarise the connection between fat distribution and CVD

Answer 6

In upper body (android) obesity

• fat storage in upper body and abdominal area
• Occurs more frequently in men
• Carries greater risk for CAD, hypertension, stroke and diabetes

In lower body (gynoid) obesity

• Fat is stored in lower body around the hips, bum and thighs
• Occurs more frequency in women