Obesity is an increased percentage of total body fat compared with normal. Overweight is increased body weight relative to height. Both have important effects on health. Body ma ss index (BMI) is one way to see whether someone is overweight. The formula for BMI is weight (kg)/height (m). Women 19 to 35 years old should have a BMI of 19 to 25, and women older than 35, of 21 to 27. Skinfold measurements are used to determine relative obesity. Waist and hip size are used to determine body fat distribution. Females with a body fat content higher than 33% are obese. An increased waist-to-hip ratio is a risk factor for diabetes and heart disease.Obesity is caused by eating too many calories for the physical activities performed. Why certain people gain too much weight isnt known. Genetics (parents passing on a tendency to gain weight to children), psychological reasons (eating when stressed), culture, and society (people are encouraged to eat too much) may play a role.What Are the Symptoms of Obesity? A women with a BMI higher than 25 is overweight; a woman with a BMI of 30 or higher is obese; and a woman with a BMI of 40 or more is severely obese. Being overweight increases the chances of having serious health problems, such as high blood pressure, diabetes, and coronary artery disease. It strains arthritic joints and causes shortness of breath and tiredness.How Is Obesity Diagnosed? The doctor will do a physical examination (weight, BMI, blood pressure) and take a medical history. The doctor may use calipers (a tool that measures thickness) to find the amount of body fat. Blood and urine tests may also be done as part of the medicalevaluation.