People with a Body Mass Index (BMI) of between 26 an 30 are classified as overweight. The BMI ist calculated as such: weight(kg)/(height(m)xheight(m)).
For example, a person weighing 60 kg and measuring 168cm in height, the Body Mass Index would be: 60kg/1,68mx1,68m=21.
BMI values above 30 are classified as obesity. Being overweight and having an abdominal fat mass that is too high (waist measurement above 80cm for women, above 94cm for men) increase the risk of developing diabetes, high blood pressure or a cardiovascular disease.