Many people use the words \u201cobese\u201d and \u201coverweight\u201d casually and interchangeably \u2014 when they are, in fact, medical terms with very different meanings.\nExcess fat is linked to a variety of chronic health conditions, including heart disease, diabetes, and respiratory problems. Being overweight or obese is the second-leading cause of preventable death in the United States, according to the National Institutes of Health, making it all the more important to understand how your weight affects your health.\nDefining \u201cOverweight\u201d and \u201cObese\u201d\nToday, more than one third of Americans are considered obese, but the definition of this term may not always be clear.\n\nThose who have a Body Mass Index between 25 and 29.9 fall within the \u201coverweight\u201d range, according to the Centers for Disease Control and Prevention (CDC). Being overweight is defined as having an excess amount of fat, causing someone to weigh more than is recommended for their height and age, putting their health at risk.\n\n\nThose who have a Body Mass Index greater than 30 are characterized as being obese, according to the CDC. Obesity is a condition in which someone is severely overweight, which puts their health at an even greater risk.\n\nCalculating Your Body Mass Index\nBody Mass Index is calculated by dividing your weight in kilograms by your height in meters squared. Use our BMI chart to find your range.\nBody Mass Index, however, can be misleading because it does not directly calculate body fat. If your Body Mass Index is outside the normal range, please discuss this with your health care provider to determine if changes are advised.\nWaist size is another method for determining obesity. Men with a waist measurement over 40 inches and women with a measurement over 35 inches are at risk for obesity.\nFind more information on the Bariatric Surgery Center for Excellence at UPMC website.\nWhat Health Complications Can Result from Obesity and Being Overweight?\nPeople who are obese are at risk for developing more than 40 different medical conditions. These are among the most common:\n\nDiabetes and insulin resistance\nHigh cholesterol\/blood pressure\nHeart disease\nOsteoarthritis (knees, hips, back)\nSleep apnea\nStroke\nSome cancers\n\nWhat Causes Obesity?\n\nAn unhealthy diet \u2013 Consuming too many calories and eating larger portion sizes can have a major impact on your health.\nNot enough exercise \u2013 Exercise not only helps to burn calories and, therefore, fat, but also changes how your body processes food. Sufficient and consistent exercise lowers the risk of obesity.\nSleep deprivation \u2013 Numerous studies have shown that sleeping too little doubles your risk of obesity. Being sleep deprived results in hormonal changes that can affect your appetite and metabolism.\nChemical changes \u2013 Research indicates that people who stop smoking often gain weight. Certain medications can also result in weight gain and a risk of obesity.\nGenetics \u2013 Some people have a \u201cfaulty\u201d gene that leads them to overeat and consume too many fatty foods, often resulting in obesity.