Physiology Health Exercise Lesson 16 z Weight control

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

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

What is obesity? z A chronic disease characterised by excessively high body fat in relation to lean body tissue. z Defined in England as having a BMI of >30 kg/m 2 3

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 4

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

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

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

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

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

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

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

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

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

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