People diagnosed with obesity have accumulated so much body fat that that it interferes with their quality of life. Obesity might have a negative effect on people’s health. If a person's bodyweight is at least 20% higher than it should be, he or she is considered obese. People with obesity have a Body Mass Index (BMI) of 30 or over. Health risks associated with obesity are: Osteoarthritis, coronary heart disease, gallbladder disease, high blood pressure, high levels of cholesterol, respiratory problems, stroke, sleep apnea and type 2 diabetes.