In America, over thirty percent of adults and fifteen percent of children are considered obese. So what exactly is obesity? Obesity is a chronic condition in which people gain excessive body weight in the form of fatty tissue. This increased body fat percentage puts sufferers at risk for more than 30 serious medical conditions, ranging from type 2 diabetes to congestive heart failure. So why are so many of us obese? Often, too much food and too little movement are to blame for obesity. In fact, decreased mobility is the biggest cause of obesity amongst the rapidly growing elderly population. Genetics plays its own role in the obesity epidemic. People with a family history of excessive weight gain are more likely to become overweight themselves. Scientists aren't sure why, but obesity is more common among the African-American and Hispanic populations than it is among Caucasians. Asian Americans are the least likely population to become obese. The simplest way to determine if you're obese is to calculate your body-mass index, or BMI. To check your BMI, you'll need to know your height in inches, and your weight in pounds. Multiply your weight in pounds by seven-hundred and three. Then, take your height in inches and square it. Divide the first figure by the second. The resulting number is your BMI. What does that number mean? Usually, the higher your BMI, the higher your percentage of body fat. If your BMI is less than 18.5, you're considered underweight. A BMI between 18.5 and 24.9 is considered normal, while one between 25 and 29.9 equates to being overweight. If you have a BMI of 30 or higher, you're considered to be obese. While knowing your BMI is a good start to diagnosing obesity, the number isn't definitive. Elderly people, or others with diminished muscle mass, may be at higher risk than their BMIs indicate. Excessive muscle mass, on the other hand, can result in a reading where by a patient who does not have excess fat appears obese by the numbers. Additionally, someone with a BMI of less than 30 can still be considered obese if he suffers from weight-related health problems such as coronary heart disease, type 2 diabetes, or sleep apnea. Examining a patient's waist circumference is another way for a doctor to determine if that patient is obese. Generally, the more weight carried above the hips, the more likely it is that this excess weight could lead to health problems. A diagnosis of obesity will be made based on a doctor's assessment of your physical health, as well as medical formulas, such as BMI. If you think you may be overweight, or have concerns about your health, please see your doctor.