Headlines ..... How do you feel? Are you bothered? What does this make you feel? Think? Are you bothered?

Learning Outcomes Explain causes of obesity Distinguish the risks associated with obesity Analyse the different methods of taking body measurements Identify the benefits of exercise

Causes of Obesity.... Obesity is linked to high fat diets and a decrease in physical activity. The energy intake in the diet should limit fats and free sugars as fats have a high calorific value per gram and free sugars require no metabolic energy to be expended in their digestion.

Exercise Advantages .... Exercise increases energy expenditure and preserves lean tissue. Exercise can help to reduce risk factors for CVD by keeping weight under control, minimising stress, reducing hypertension and improving HDL blood lipid profiles. Not to mention epigenetic evidence ..... http://www.youtube.com/watch?v=J3A9g0STeE4

Risk of being obese Obesity is a major risk factor for cardiovascular disease and type 2 diabetes. Obesity is characterised by excess body fat in relation to lean body tissue (muscle). A body mass index (weight divided by height squared) greater than 30 is used to indicate obesity. Accurate measurement of body fat requires the measurement of body density.

Health measurements BMI (body mass index) Need height Need waist BMI = Mass kg / height m2 But wait .....

Health measurements A waist to hip ratio of more than 0.95 for men and 0.85 for women is “apple” shape – more PRONE to heart disease Waist/Hip Measuring tape To determine the ratio, divide your waist measurement by your hip measurement. http://www.virginactive.co.uk/active-matters/tools/waist-hip-ratio

Estimating Percent Body Fat Skinfold measurements: Folds of skin are measured with a caliper. The measurements are used in equations that link the thickness of skinfolds to percent body fat calculations made from more precise experiments.

Health measurements Percentage fat From skin fold or Electric impulse Nowadays a pod can be used Description Women Men Essential fat 10–13% 2–5% Athletes 14–20% 6–13% Fitness 21–24% 14–17% Average 25–31% 18–24% Obese 32%+ 25%+ http://www.virginactive.co.uk/active-matters/tools/waist-hip-ratio

Measurements from yesterday ... BMI Waist/Hip ratio Percentage fat Skin fold callipers So why do we need fat?

In cell membranes Essential for hormones etc.

Essential Fatty Acids Body cannot synthesise (so need to be supplied in diet) Fat soluble vitamins (A,D,E and K) only enter our diet in fats SO fats are essential to our diet to avoid deficiency symptoms e.g. linoleic acid deficiency (scaly skin, hair loss) Also for .....

Review What is meant by the term obesity? Give the formula for calculating BMI What are the 2 main ways in which an obese person can reduce the risk factors for CVD? What is the disadvantage of sugary food? TYK – p195

Answers Accumulation of body fat in relation to lean muscle tissue BMI = Body mass / height2 Lose weight and take regular exercise Free sugars expend no energy to digest them

Summary - Obesity Obesity is linked to high fat diets and a decrease in physical activity. The energy intake in the diet should limit fats and free sugars as fats have a high calorific value per gram and free sugars require no metabolic energy to be expended in their digestion. Exercise increases energy expenditure and preserves lean tissue. Exercise can help to reduce risk factors for CVD by keeping weight under control, minimising stress, reducing hypertension and improving HDL blood lipid profiles.

Summary - Obesity Obesity is a major risk factor for cardiovascular disease and type 2 diabetes. Obesity is characterised by excess body fat in relation to lean body tissue (muscle). A body mass index (weight divided by height squared) greater than 30 is used to indicate obesity. Accurate measurement of body fat requires the measurement of body density.