Obesity: What i tis, what are the causes, and how to treat it

Obesity is a risk factor for the development of serious diseases. Learn what it is, the causes and how to treat it

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With a high incidence in Portugal, obesity is one of the leading causes of premature death. Learn what it is and how it can be prevented.

The prevalence of obesity worldwide has more than doubled since 1980: 39% of the global population is overweight or obese, and in Portugal, this percentage rises to 42%. However, despite its high incidence, the consequences of this scourge are still undervalued. Therefore, it is time to take a closer look at this serious public health problem. Discover what obesity is and what you can do to prevent it.

What is obesity?

Obesity is a chronic and serious disease of epidemic and global proportions, defined as an abnormal or excessive accumulation of fat. In simple terms, it occurs when the amount of calories consumed exceeds the amount expended by the body for its maintenance and daily activities. It is not just a cosmetic problem - it compromises health, increases the risk of long-term complications, and reduces life expectancy.

Obesity is one of the most prevalent and underdiagnosed diseases today. It is also a risk factor for many other diseases.

What are the main causes of obesity?

Obesity is a chronic multifactorial disease primarily associated with improper diet and sedentary lifestyle. However, there are other risk factors for the development of obesity.


A high consumption of calorie-dense foods is a significant cause of energy imbalance in the body, leading to weight gain and obesity. Nutrient-poor calories derived from the consumption of fast food, sweets, and high-calorie beverages are practices to be avoided. The lack of healthy habits, such as not including fruits, vegetables, and legumes in the daily diet in appropriate proportions, creates a conducive environment for weight gain.

Sedentary Lifestyle

A sedentary lifestyle significantly increases the risk of obesity. Nowadays, society is structured for lower levels of physical activity. Therefore, it is necessary to find ways to combat daily passivity in order to increase calorie expenditure.


Obesity can be a secondary disease to other clinical conditions, such as Cushing's syndrome, hypothyroidism, or diabetes. Hormonal changes can also contribute to obesity, although they rarely constitute the sole cause. Additionally, medical conditions that limit mobility, such as arthritis, can also contribute to weight gain due to reduced activity levels they entail.


Some medications can cause weight gain as a side effect, such as certain antidepressants, corticosteroids, contraceptives, diabetes medications, antipsychotics, steroids, and beta-blockers - some due to direct action, others by inducing a reduced sense of satiety.


The genetic background of the organism contributes to around 25 to 40% of obesity development. It can determine the energy expenditure of the body, appetite, or how the body processes nutrients. However, the explanation for obesity should not be solely attributed to genetic inheritance. Obesity results from the interaction of multiple genes, environmental factors, and behavioural factors.

Psychological factors

Inadequate emotional management, low self-esteem, anxiety, or depression can pave the way for eating disorders. In this case, food serves as an emotional outlet (rather than a means of providing the body with necessary nutrients), often being consumed intensely and uncontrollably.

How to determinate if you are at risk of obesity?

The three main measures to assess obesity are Body Mass Index (BMI), waist circumference, and body composition.

Body Mass Index (BMI)

BMI is obtained by dividing weight by height squared. For example, for a person weighing 70 kg and with a height of 1.68 meters, the BMI is calculated as 70 / (1.68 x 1.68) = 24.8. Based on the obtained value, we can classify weight as follows:

  • Underweight - BMI < 18.5
  • Normal weight - BMI 18.5 - 24.9
  • Overweight - BMI 25 - 29.9
  • Obesity - BMI > 30
  • Moderate obesity - BMI 30-34.9
  • Severe obesity - BMI 35-39.9
  • Morbid obesity - BMI > 40

Abdominal Circumference

Assessing obesity using BMI should be complemented with measuring abdominal circumference (AC). This value is related to the abdominal distribution of fat, which is more detrimental to health, and changes at this level are associated with an increased risk of diseases, especially cardiovascular and metabolic conditions. The following are the normative values:

  • Increased risk of metabolic complications: Female: ≥ 80 cm | Male: ≥ 94 cm

  • Substantially increased risk of metabolic complications: Female: ≥ 88 cm | Male: ≥ 102 cm

Body Composition

The diagnosis of obesity is complete with the values obtained from the assessment of body composition using a test called multifrequency electrical bioimpedance. This test is widely used in nutrition consultations and gym evaluations. Nowadays, there are even smart scales available for home use that can perform this measurement. By passing a low-intensity electrical current through the body’s, the body composition is evaluated based on the approximate amount of muscle, bone, and fat.

What are the consequences of obesity for health?

Obesity is a major risk factor for the development of serious diseases that reduce the quality of life and increase morbidity and mortality, such as:

  • Cardiovascular diseases, such as high blood pressure and ischemic heart disease;

  • Metabolic and endocrine disorders, such as type 2 diabetes, metabolic syndrome, and dyslipidaemia;

  • Musculoskeletal disorders, such as osteoarthritis;

  • Respiratory disorders, such as dyspnoea and sleep apnoea;

  • Stroke;

  • Infertility;

  • Certain types of cancer;

  • Psychological problems.

Most of the time, it is these conditions that lead obese patients to seek help rather than the factor that caused them (obesity) itself. As a consequence, clinical conditions are often identified at a late stage, making treatment and achieving results more difficult. That is why information campaigns about obesity are so necessary - a preventive, proactive, and informed approach could easily prevent a large number of serious illnesses and even deaths.

What is the treatment for obesity?

Given that the main risk factors for the development of obesity are sedentary lifestyle and poor eating habits, these are the two areas of focus for prevention and intervention: a healthy diet and an active lifestyle.

Dietary Recommendations

Reduce the quantity of food consumed during meals and only eat what is necessary to feel satisfied. Additionally, avoid the intake of harmful sugars and fats, and opt for healthy fats such as olive oil, nuts, and avocado. Vegetables should always be present in main meals, and fruits in daily snacks. Consuming protein-rich foods can help increase satiety.

The best way to ensure that your diet is balanced for your body and lifestyle is to seek the guidance of a nutritionist. This way, you will receive personalised recommendations tailored to your needs and desired results. Making drastic changes to your diet without professional supervision can pose risks to your health.

Recommendations for physical activity

The World Health Organization recommends engaging in 300 minutes of light to moderate physical activities per week, as well as 150 minutes of vigorous physical activities. What does this mean? While any activity that keeps your body active is beneficial, such as walking, gardening, or cleaning the house, it's important to set aside dedicated time in your schedule for more specialized exercises like weightlifting or aerobic activities.

One of the most popular ways to achieve this goal is by attending a gym or having training sessions with a Personal Trainer. However, remember that even after achieving your desired weight loss, exercise remains essential for long-term weight maintenance.

Are there surgical solutions for obesity?

Surgery can be an important ally in the treatment of obesity. It is especially relevant when the disease is in its most severe form and is accompanied by other associated conditions. The presence of diabetes, fatty liver disease, hypertension, sleep apnoea, dyslipidaemia, or orthopaedic problems should be taken into consideration in this decision.

Therefore, when attempts to treat obesity through the adoption of a healthy lifestyle prove insufficient to control weight loss, surgical intervention is considered as a therapeutic option. The specialist physician may recommend one of two options: Obesity Surgery and Apollo Method Surgery.

Bariatric Surgery

Bariatric surgery involves reducing the size of the stomach so that the patient can feel full with a smaller amount of food. The procedure is performed laparoscopically, meaning the surgeon inserts the necessary instruments through small incisions in the abdomen, including a tiny camera that allows for visualisation and guidance during the surgery.

This form of treatment is less invasive compared to traditional surgeries, resulting in a shorter recovery time for the incisions to heal (usually between 2 and 7 days). The patient can continue to eat normally to allow for the recovery of the digestive system. At Joaquim Chaves Saúde, you will find all the technological and human resources for this treatment.

Intervention by Apollo Method

Joaquim Chaves Saúde offers a team with extensive worldwide experience in the Intervention by Apollo Method, led by Dr. López-Nava. It is a minimally invasive endoscopic procedure, meaning there are no cuts or scars. It involves suturing the stomach wall to reduce its size, allowing the patient to feel satisfied with smaller food intakes.

The Intervention by Apollo Method is performed under anaesthesia and has an approximate duration of 60 minutes. As one of the safest and most effective endoscopic procedures, the patient can be discharged from the hospital on the day following the procedure.

Joaquim Chaves Saúde by your side to fight obesity

Taking care of your health is our priority, which is why we provide the best means and resources to combat obesity. You can rely on a team of experienced nutritionists, ready to help you step by step in adopting healthy eating habits. This specialty is available at Moscavide Medical Centre, Carcavelos Surgical Clinic, Entrecampos Clinic, Faro Clinic, Miraflores Clinic, and Sintra Clinic.

And because we understand that physical activity is an essential element for maintaining well-being and preventing obesity, we have expanded our offering with Joaquim Chaves Fitness Restelo. In this gym, you will be always supported, not just when using the facilities - this is the key to achieving the necessary results to improve your quality of life and well-being. Book your appointment now.


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Get to know this area of health and find the right care for you.

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