Types of obesity: characteristics and risks

The risks and consequences associated with excess body weight.

Obesity is a chronic disease with a high prevalence worldwide that is generally associated with a multitude of health complications.

Scientific data show that this phenomenon seems to be on the rise in recent years, making it a public health problem, especially in developed countries.

Overweight: a worrying reality...

The World Health Organization (WHO, 2015) affirms that in the world there are 1.9 billion adults who are overweightof which more than 600 million suffer from obesity. In Spain, obesity has also become a serious problem, and this is confirmed by data from the ENRICA study, which concludes that 39% of the Spanish population is overweight and 22.9% obese.

Due to the complexity of this phenomenon, the most effective treatment to combat this condition is composed of three basic pillars: nutrition, psychological aspects and physical exercise..

Causes of obesity

The obesity is a multicausal phenomenon and, therefore, the causes obey to several factors: those of genetic and endocrine origin, which account for 30%, and those of environmental origin, which account for 70%..

The latter include excessive food intake, especially unhealthy products, lack of physical exercise and, in general, a sedentary lifestyle.

Obesity and serious health problems

Obesity brings with it serious health problems for people affected by this condition.. As concluded by Miguel Soca and Niño Peña in a 2009 research study: "Obesity can cause a set of metabolic abnormalities, called metabolic syndrome (MS): a series of disorders characterized by glucose intolerance, diabetes, alterations in Blood lipids and increased blood pressure".

Likewise, obesity negatively affects life expectancy and quality of life, as well as body aesthetics which, consequently, can cause social and psychological problems for the individual with this condition.

Diagnosis of obesity

Obesity is diagnosed, rather than by weight, by the percentage of body fat of the individual. Generally speaking, in the adult male, approximately 12-20% of his body weight is composed of fat. In the case of women, the percentage is slightly higher, 20-30%, mainly due to hormones such as estrogen.

Nowadays, different methods exist to quantify the percentage of body fat. Biompedance, X-ray engineering or densitometry are some examples. However, one of the most widely used methods is the Body Mass Index (BMI), obtained by the ratio between weight expressed in kilograms and height in meters squared (BMI: weight/height2). With the result of this index overweight is defined as individuals with a BMI equal to or greater than 25 kg/m2 and obese as those with a BMI equal to or greater than 30 kg/m2..

• Recommended article: "The application of Cognitive-Behavioral Therapy in the treatment of obesity".

Calculating the body fat percentage

BMI is an easy measure to obtain, with a high correlation with body composition, and is useful as a diagnostic value. In addition, the higher the BMI of an individual, the greater the likelihood of developing morbidities associated with excess fat.. However, BMI has its limitations and has been criticized for not allowing differentiation between the percentage of fat and muscle mass.

If the percentage of fat mass is considered, obesity corresponds to a fat percentage greater than 25% in men and 30% in women. To estimate the percentage of body fat, skinfolds are a very valid option. With this method it is necessary to make the sum of four folds: the bicipital, tricipital, subscapular and suprailiac folds.

Finally, another of the measures used for the diagnosis of obesity is the waist-to-hip ratio (WHR), a specific anthropometric tool for measuring intra-abdominal fat levels. This formula divides the waist circumference by the hip circumference (WHR: waist circumference in centimeters/hip circumference in centimeters). The WHO establishes normal levels for the waist-to-hip ratio of approximately 0.8 in women and 1 in men.

Types of obesity

Obesity can be classified in different ways depending on the criteria to be established. One of the most commonly used classifications is based on the distribution of body fat, in which there are three categories. According to the SEEDO Consensus (2007), they are as follows:

1. Obesity of homogeneous distribution.

Excess fat does not predominate in any one area of the body, which is why it is called homogeneously distributed obesity.

2. Gynoid or peripheral obesity (pear-shaped)

The fat is basically located in the hips and thighs. This type of distribution is mainly related to venous return problems in the lower extremities (varicose veins) and knee osteoarthritis. Women are more prone to this type of obesity.

3. Android, central or abdominal obesity (apple-shaped)

Excess fat is located in the area of the face, thorax and abdomen. It is associated with an increased risk of dyslipidemia, diabetes, cardiovascular disease and mortality. This type of obesity is more common in men than in women.

Other classifications of obesity

In addition to the above classification, there are others such as the following:

Types of obesity according to degree of risk.

According to the consensus of the Spanish Society for the Study of Obesity (SEEDO 2007), obesity can also be classified as follows, taking into account the BMI:

• UnderweightUnderweight: The weight is below normal. BMI is less than 18.5 kg/m2. It is not considered overweight.
• NormopesoIt is the normal weight of a person in relation to his or her height. The BMI is the ideal: 18.5-24.9 kg/m2. It is not considered overweight.
• OverweightOverweight: Overweight occurs when a person weighs more than what he/she should weigh for his/her height. BMI 25-26.9 kg/m2.
• Overweight IIThe person is heavier than he/she should be for his/her height but is not obese. BMI 27-29.9 kg/m2.
• Obesity type IFirst degree of obesity. BMI 30-34.9 kg/m2.
• Obesity type IISecond degree of obesity BMI 35-39.9 kg/m2.
• Obesity type IIIThis type of obesity is also called morbid obesity. BMI 40-49.9 kg/m2.
• Obesity type IVThis type of obesity is also known as extreme obesity. BMI greater than 50 kg/m2.

Types of obesity according to the cause

Depending on the source causing the obesity, it can be:

• Genetic obesityObesity: the individual has received the genetic inheritance or predisposition to have obesity.
• Dietary obesitycharacterized by a sedentary lifestyle and unhealthy food intake.
• Maladjustment obesityThe person never feels satiated due to a maladjustment in the hunger regulation system.
• Obesity due to thermogenic defectThe organism does not burn calories efficiently.
• Nervous type obesityThis is obesity caused by psychological problems such as anxiety, stress and depression.
• Obesity due to endocrine diseasesIt is the obesity caused by hormonal diseases, for example, hyperthyroidism.
• Chromosomal obesityThis type of obesity is associated with chromosomal defects.

Bibliographic reference:

• Rodriguez Artalejo F. (2011) Epidemiology of obesity in Spain: ENRICA study. V NAOS Convention. Madrid: Centro de Investigación Biomédica en red Epidemiología y Salud Pública.