There is a parameter that lets you easily define the existence of obesity, body mass index (BMI):
BMI (kg/m2) = Actual Weight / Height x Height
* Weight in Kg
* Length in meters

Obesity is a carrier of any person with a Body Mass Index (BMI) greater or equal to 30 kg/m2. Body Mass Index (BMI) also serves to classify the different degrees of obesity:
* BMI 30-40 kg/m2, moderate obesity
* BMI> 40 kg/m2, extreme obesity.

In Spain the prevalence of obesity, according to a study led by Javier Aranceta and collaborators in 1995, was 13.4% in men and women aged 25-60 years. What is more worrying is the fact that it is increasing.

Another important aspect from the point of view of morbidity (increased risk of illness) and mortality, is the fact that people with a BMI over 30, have an increased risk of diabetes (excess weight causes a resistance to insulin and may be caused by either a carbohydrate intolerance, but not all obese people are diabetic and vice versa), hypertension (with increasing body mass, the heart must pump more blood, which is an increase in the values of blood pressure)…,

hyperuricemia and gout (the overeating of foods high in protein causes an increase in uric acid synthesis, especially if there is glucose intolerance), gallstones, hyperlipidemia (high blood cholesterol and triglycerides associated with other risk factors and not only to obesity), respiratory (apnea, snoring?), digestive problems, problems walking, hip and knee osteoarthritis (coxarthrosis and gonarthrosis), psychological and social problems (due to patterns of beauty and the general rejection of obesity in society) and cardiovascular disease.

However when considering the cardiovascular risk is not only important consideration in BMI, but also the distribution of body fat. It is shown that the distribution of abdominal fat is a cardiovascular risk marker more sensitive than BMI itself.

A ratio or waist / hip ratio (measured at umbilicus and hip, respectively) higher than 0.95 in men and 0.80 in women, is associated with an increased risk of cardiovascular disease and Diabetes Mellitus.