According to data from the National Center for Health Statistics, one-third of American adults are obese. Being overweight or obese increases your risk of certain health problems, such as high blood pressure and diabetes. Your body mass index can help you evaluate your risk of weight-related health problems and determine how much weight you need to lose to reach a healthy range.
Definition of Obesity
The Centers for Disease Control and Prevention (CDC) defines obesity as a range of weight "greater than what is considered healthy for a given height." Obesity is also a condition that increases the risk of certain health problems and diseases, including heart disease and some types of cancer.
Causes of Obesity
The causes of obesity are numerous and diverse. The CDC notes that, in broad terms, obesity is the result of an "energy imbalance." When you consume more calories than you burn, you gain weight. Prolonged imbalances between your diet and activity level can eventually lead to excess weight that puts your health at risk. Genes, metabolism, behavior and environment can play a role in obesity. Some diseases, such as polycystic ovary syndrome, can contribute to weight gain, as can certain medications such as steroids and antidepressants. According to The New York Times, associating with obese or otherwise unhealthy individuals can also increase your chances of becoming obese.
Body Mass Index
Your body mass index is a measurement used to identify possible weight problems. BMI correlates with, but does not directly measure, your amount of body fat. To calculate your BMI, divide your weight in pounds by height in inches squared and multiply that number by 703. For example, if you are 5-feet-5 and you weigh 150 pounds, your BMI would be 24.96, or 150 divided by 4225, multiplied by 703.
Interpreting Your BMI
For adults 20 or older, BMI interpretation is the same for men and women. For children and teens younger than 20, BMI interpretation varies depending on age and gender. For adults, a BMI between 18.5 and 24.9 is considered healthy. Overweight is indicated by a BMI between 25.0 and 29.9, and a BMI over 30 is considered obese. A BMI above 40 indicates morbid obesity, which is usually marked by excess weight of 100 pounds or more.
Health Risks of Obesity
While BMI is helpful in identifying potential health risks, but it is not the only factor. Abdominal fat---measured by waist circumference---and physical inactivity are also predictors of obesity-related health problems. Obesity brings an increased risk of high blood pressure and cholesterol, type 2 diabetes, heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, abnormal menstrual cycles or infertility in women, and certain forms of cancer, including breast, prostate and colon. Obesity is also associated with higher mortality rates from all causes.
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