Obesity: the epidemic of the 21st century

The World Health Organization (WHO) defines obesity as the "abnormal and excessive accumulation of fat that can be harmful to health and is manifested by excess weight and body volume". This disease is a growing problem worldwide and affects people of all ages.

This disease reaches worrisome numbers in the United States, where the adult obesity rate exceeded 42 percent in 2020, according to the State of Obesity: Better Policies for a Healthier America study, published by Trust for America’s Health (TFAH).

Within this phenomenon there is something even more worrying: childhood obesity. According to the WHO, 216 million children and adolescents in the world are overweight and 124 million are obese.

Obesity was recognized as a disease by the WHO in 1997. In addition, its rapid expansion has made it a 21st century epidemic. We have all heard about it, but do we know exactly how it is diagnosed or what types exist?

Diagnosis of obesity


Obesity is diagnosed by the Body Mass Index (BMI), the relationship between a person’s mass and height. Based on this indicator it is possible to determine if someone is overweight or if they have an adequate weight. Therefore, the BMI is calculated by dividing the weight (in Kg) by the height (in meters squared). Obesity is considered when someone has a BMI of 30 kg/m2 or higher.

However, it should not be confused with the percentage of body fat. Generally speaking, there may be a relationship between a high BMI with a high body fat index, but this is not always the case. Those with a high percentage of muscle mass (such as bodybuilders) can have a high BMI and not be overweight or obese.

In another order of things, there are different factors (risk, fat distribution and the cause) through which we can classify the types of obesity.

Types of obesity according to fat distribution

Abdominal or android obesity (apple-shaped): The location of excess fat is in the abdomen, chest, and face. It is highly associated with diabetes and various heart diseases.

Peripheral or gynoid obesity (pear-shaped): Accumulated fat is mostly found in the thighs and hips. Women are more likely to accumulate fat in these areas. In addition, this type is related to problems such as varicose veins and osteoarthritis in the knees.

Homogeneous obesity: there is no predominance of excess fat in a localized area, but fat is distributed by the body in the same proportions.

Types of obesity by cause


Genetics: a very common obesity occurs when the patient has a genetic heritage or a certain predisposition to suffer from this disease

Dietetic: is another one of the most common. It occurs due to the union of sedentary and nutritious food and high caloric value or because of a calorie consumption greater than the energy that is spent daily.

Obesity by maladjustment: appears due to a failure in the perception of satiety. That is, when a person feels unsatisfied after eating or feels the need to eat continuously.

Thermogenic defect: not a very common type of obesity. This occurs when the body is not able to burn calories efficiently.

Nervous obesity: it develops in people who have other pathologies such as hypoactivity or different psychological problems. The author of this obesity is the central nervous system, which alters the mechanisms of hunger and satiety

Endocrine diseases: this type of obesity, less frequent, is caused by diseases of the endocrine system, such as hypercorticism, hypothyroidism or hyperinsulinism.

Drug obesity: there are some drugs (corticosteroids or antidepressants) whose side effects include fat buildup and obesity.

Chromosomal obesity: associated with chromosomal defects, such as Down syndrome or Turner syndrome.

Causas y consecuencias de la obesidad:

Obesity has experienced significant growth in recent decades as a result of social, economic and cultural changes in the population. Among the most common causes we find:

Bad diet: a diet rich in fat, salt and sugars (very present in pastries and fast food) is the main cause of obesity. These foods are excessively caloric and have a very low nutritional value that do not bring anything beneficial to health.

No or little physical exercise: sedentary lifestyle is the cause of many diseases, since the human being is a species configured to move. When a person does not move around enough during the day, he does not burn enough calories and therefore ingests more energy than he consumes, causing a constant weight gain.

Lack of sleep: hormonal changes can occur if the body gets used to sleep less than 7 hours.

Medical problems: for example, Prader-Wili syndrome, Cushing syndrome, polycystic ovary syndrome, among others.

Socioeconomic factors: obesity is related to low income. Fast food is perceived as cheaper than healthy food. Therefore, people with little purchasing power have more access to unhealthy food.

But these are not the only causes, there are also other factors such as emotions, lifestyle, genes, psychological problems or alcohol that can encourage the development of obesity.

The consequences of obesity are not just the obvious physical changes. Obesity can make a person more likely to suffer from serious diseases: hypertension, heart disease, cancer (of uterus, cervix, ovaries, breast, colon, rectum and prostate), depression, infertility, diabetes, liver disease, osteoarthritis and skin problems, among others.

Therefore, it is a public health problem, so preventing the disease from the first years of life is an essential task.

Childhood obesity: a long-term problem


In the childhood and youth stage, this disease is even more worrying, as it usually extends to adult life. An obese child may be prone to diseases in his or her adult life such as type 2 diabetes, high blood pressure, dyslipidemia, cardiovascular diseases, etc. Therefore, an intervention from childhood is necessary to prevent them:
“The early stages of life are key to adopting healthier eating and lifestyle habits, which reduce the risk of developing chronic diseases and will remain in adulthood. Monitoring the intake of energy and nutrients is essential for the planning of diet improvement strategies [...] a healthy, varied and balanced diet is recommended, increasing the consumption of fruits and vegetables and reducing the intake of salt, saturated fatty acids and sugars, together with moderate physical activity on a daily basis”

Spanish Ministry of Health, Social Services and Equality (literal translation of Ministerio de Sanidad, Servicios Sociales e Igualdad). Agencia Española de Consumo, Seguridad Alimentaria y Nutrición, 2017. 

Treatment of obesity

In any case, to start a treatment against a disease the main thing is to go to the specialist doctor, who will diagnose it and prescribe the appropriate treatment. However, two elements are vital to curb obesity or overweight: a healthy diet and daily physical activity.

Healthy eating

An obese person should go to a nutritionist to dictate the diet they need to follow. This specialist will distribute the macronutrients throughout the daily meals taking into account the calories of each of them and the level of physical activity of the subject.

Proteins, carbohydrates, fats, water, vitamins, and minerals will be organized in such a way that the patient receives all of the sufficient energy without falling into a caloric surplus.

Physical activity

People who are obese should do daily physical activity. Between 30 and 60 minutes of training a day are essential, but so is the constant natural movement, because the human being is a species made to walk. Training 1 hour a day is of little use if the person is sitting or lying down for the remaining 23 hours. Simple tasks such as walking, cleaning and playing with children, among others, are extremely important.

At this point the professionals of the Sciences of Physical Activity and Sport come into value: they are experts trained and prepared to help people with their physical routine.

If the task of training people with diseases associated with sedentary lifestyle (or even sarcopenia or loss of muscle mass) falls on the wrong hands, the consequences can be enormous. Therefore, those who are going to train overweight or obese people have a responsibility and require a more precise specialization.

From AreaZero we want to provide knowledge and specialization to physical activity professionals with our online training. 
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