1. Physiology, Health & Exercise
Lesson 16
Weight control & obesity
Effects of exercise on body composition & weight control

2. Weight Control & Obesity
Includes:
The problem of rising incidence of obesity in UK
Possible causes of obesity
Possible treatments of obesity
Effect of exercise on body composition & weight control

3. What is obesity?
A chronic disease characterised by excessively high body fat in relation to lean body tissue.
Defined in England as having a BMI of >30kg/m2

4. What is the scale of the problem with obesity?
Based on data from England:
Year
% males
% females
1980 6 8
1997 17 20
Write a statement to describe this data

5. Scale of the problem In Scotland:
14% of men and 17% of women classed as obese
Approx 20% of children are overweight
8% of boys and 7% of girls are obese

6. Health Risks associated with obesity
Higher risk of developing:
CVD- including CHD & high blood pressure
Type 2 diabetes
80% of sufferers are obese
Traditionally seen as a disease of over 40s now found in children as young as 13

7. Health Risks associated with obesity
Higher risk of developing:
Cancers of e.g. colon, breast (maybe also uterine & ovarian)
Osteoarthritis (due to excess pressure on joints)
Respiratory problems (due to excess weight over the lungs)

8. Health risks Other consequences: Time off work due to illness
Reduced life expectancy
Economic implications

9. Causes of obesity Complex & interrelated & include: Environmental
Genetic
Psychological
Metabolic
Dietary
If constantly consume more calories than expend then will eventually become obese

10. Causes of obesity 2 reasons for steep rise in last 20 years:
Decrease in physical activity both at work & leisure
Energy dense (high fat) diet

11. Treatment of obesity Need to reduce energy intake & increase EE
Weight loss more likely to be maintained if levels of physical activity are increased by permanent lifestyle changes

12. Effect of exercise on body composition & weight control
Important that activity is regular & strenuous enough to make person breathe more heavily than usual
E.g. brisk walking, jogging, swimming, dancing
Experts (e.g. HEBS) suggest everyone should do up to 30 mins moderate-intensity exercise most days
Remember max heart rate is 220-age

13. Effect of exercise on body composition & weight control
Exercise increases/helps to:
Energy output relative to input
Fat loss
Preserve lean tissue
prevent obesity

14. Effect of exercise on body composition & weight control
The impact of exercise on body composition decreases as the fat content decreases