Physical Activity & Obesity

Obesity

• Excess body fat that has ill-effect on health• Measures of body fat

1. Waist Circumference/Girth2. Body Mass Index (BMI) – most widely used method

of measure body fat; Indirect measure• Height to Weight Ratio – weight (kg)/height (m2)• Problematic for individuals with a lot of muscle mass

(e.g. Rugby and American Football players, Bodybuilders)

3. Skinfold test/Calipers – indirect measure, problematic – errors are common, thus the reason multiple sites are taken.

Obesity Cut Off Points

• BMI– Underweight < 18.5– Normal Weight 18.5 – 24.99– Overweight 25 – 29.99– Obese Class I 30 – 34.99– Obese Class II 35 – 39.99– Obese Class III > 40

Obesity Cut OffsBody Fat Percentage

Chart - Health Enclave

Obesity Cut Offs

Major Health Consequences• Cardiovascular diseases– CHD - Atherosclerosis, Stroke, Hypertension

• Type 2 Diabetes – insulin resistance• Osteoarthritis – joint disease– Carrying around too much weight– Cartilage is damaged – bones rub against each

other• Respiratory problems – sleep apnea, COPD– Inflammation in the lungs – decreased lung

volume– Difficulty breathing – airways are closed

• Cancer – Bowel/colorectal, colon

Energy Balance

• Energy intake > Energy output = weight gain• Energy intake < Energy output = weight loss• Energy intake = Energy output = maintenance,

remains the same

Hormone Regulation

• Leptin – hormone released from fat cells after we eat– Regulates appetite and feelings of hunger and

satiety– Aids in healthy weight if working properly

• What other hormone is released after we eat?