32.9% of the adults in the United States are obese according to a 2003-2004 study. A similar study done from 1976-1980 found less than half that, 15%, obese. Indeed we have an epidemic.
Body Mass Index (BMI) is a measure calculated from a person's weight and height. It provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems. BMI is calculated by dividing your weight in kilograms by your height in meters squared. That number should be between 18.5 and 24.9. The National Institutes of Health has defined certain classifications of weight based upon the BMI:
Classification |
BMI Range |
Underweight |
Less than 18.5 |
Normal |
18.5 - 24.9 |
Overweight |
25.0 - 29.9 |
Obese |
30.0 - 39.9 |
Extreme Obesity |
|
You should discuss with your physician whether your goal should be to attain a normal BMI. For people with a lot of muscle mass, such as trained athletes, a healthy BMI may actually be somewhat higher than what the table would indicate. For most people, however, these categories are a useful guide.
Another body measurement that is related to health risk is the waist circumference. It seems that the location of fat makes a difference as far as health risk. Fat in the waist carries a greater health risk than fat in hips or thighs. Scientific studies have shown that people whose waists exceed the targets in the table below have a higher risk of health problems.
Gender |
Healthy Waist Circumference |
Men |
Less than or equal to 40
|
Women |
|
Effects on Health
Being overweight or obese increases the risk of developing many diseases and conditions including high blood pressure, coronary heart disease, stroke, type 2 diabetes, sleep apnea, high cholesterol levels, high triglyceride levels, osteoarthritis and gallbladder disease. It even increases the risk for endometrial cancer, breast cancer and colon cancer.
During pregnancy, obesity increases the risk of death for both the baby and the mother and raises the maternal risk of high blood pressure by a factor of ten. The woman who is obese during pregnancy has an increased risk of gestational diabetes and problems with labor and delivery. The infants of these obese women have a higher birthweight which leads to a higher rate of Cesarian section with its higher rate of complications. These infants often have low blood sugar which can lead to brain damage and seizures. In addition, these infants have a higher risk of birth defects.
The attainment of a normal weight can lower these risks. A report from the Surgeon General stated that an overweight individual can reduce their risk of heart disease even by just losing 5-15% of their body weight. So there is definitely hope to improve your health risk. For the rest of this module and in the subsequent ones, we will give you the necessary information to help you succeed. It's up to you to not just read it and answer the test questions, but to use it!
A Simple Formula
Being overweight or obese is due to an energy imbalance. More calories are eaten or consumed than are used in the activities of the body. To lose weight you must do the opposite:
Formula For Weight Loss: Calories Out (Activity) > Calories In (Food Eaten)
Body weight is the result of heredity, environmental factors and individual behaviors. While you can't change your heredity, you can alter your environment and your individual behaviors. That is where your power lies. You'll lose the most the fastest when you eat less and burn more. So, an exercise regimen is an important part of the formula. After being cleared by your doctor, you will need to build up your routine, but it will be worth it!. In addition to helping you lose weight, exercise provides other health benefits including improving your cardiovascular fitness.
In the next module, we'll look at some important information about nutrition. In the meantime, use the Practice Tests to learn this information.