Understanding Body Composition and Its Impact on Health

1. Chapter ?? LESSON 2 Healthy Body Weight

2. Journal Question Have you tested your body fat levels or your fat distribution? If so, what do you remember about the experience? If not, what do you think the experience would be like?

3. Obesity Is on the Rise • Over 1/3 of adults are overweight or obese. • Almost 20% of children aged 2 to 19 are obese. Rates of overweight and obesity have increased dramatically. • Sedentary living has increased. • Foods high in fat and calories are cheaper and are more available than in the past.

4. Weight and Body Mass Index • Body mass index (BMI) is weight in kilograms divided by height in meters squared. • BMI is used to determine if a person is overweight. • It is inexpensive and easy to administer and is used in large studies. • We can’t determine whether the weight is muscle or fat, so BMI is not foolproof. • BMI also does not account for physical activity levels. • It’s possible to have a high BMI but also high muscle mass and be very active.

5. BMI and Health Risks • People with a BMI over 30 and two other known health risks are at higher risk for a variety of diseases and death. • High blood pressure, blood cholesterol, or blood sugar • Family history of heart disease • Physical inactivity • Smoking

6. Body Composition • Body composition is amount of body mass that is made of body fat. • High levels of body fat, regardless of body weight, may be associated with higher disease risk. • Obesity is having too much body fat. • Technically, obesity is very different from overweight. The two are often related and the terms are often used together.

7. Body Fat Essential Body Fat Storage Body Fat Fat stored on the body in addition to essential body fat Provides a reserve of energy for the body Provides additional insulation and cushioning Acceptable total body fat levels: Males: 6 to 25% Females: 13 to 31% • Cushions and supports organs • Insulates the body • Helps with nervous system functioning • Necessary for hormone function • Necessary for healthy reproductive function, especially in women Being too lean can cause serious health problems.

8. Body Fat Distribution Upper Body Fat Lower Body Fat Fat located around the hips and thighs Associated with estrogen metabolism and reproduction in females Less active than upper body fat Less dangerous than upper body fat • Fat located around the midsection of the body • Influenced by testosterone • Very active and mobile • Associated with higher risk of disease

9. Apple Versus Pear Body Shape

10. Health at Every Size • Weight and body composition alone don’t define a person or total health. • Weight may be less important overall than physical inactivity: • Those who are normal weight but sedentary are known to be at higher risk for disease than those who are slightly overweight but physically active. • Weight cycling (periods of losing and gaining weight) is also more dangerous than remaining weight stable, even if you are somewhat overweight.

11. We Are Not All Meant to Be the Same Size

12. Influences on Weight and Health • Genetics influences overall size, weight, body fat, and shape. • Genetics also influences how a person responds to physical training and dieting behaviors. • Socioeconomic status also influences weight. • Those with more money and resources can afford a greater variety of healthy foods as well as access to fitness and recreational opportunities.

13. Toxic Food Environment • A toxic food environment is one in which food is plentiful and inexpensive while also being higher in fat and calories than necessary. • A healthier nation will require more than just individual effort. We must also work together to reduce the toxicity of our food environment for all people. • This requires reducing access to unhealthy foods and increasing access to healthy foods.