Obesity as a Chronic Disease

Obesity has been recognised by the World Health Organisation (WHO) as a chronic disease and is now included as a diagnosis in the International Classification of Diseases (ICD).

Overweight and obesity lead to secondary diseases, depending on the severity, duration of the disease and individual predisposition. In addition to cancer, lung and joint diseases, the development of cardiovascular risk factors such as diabetes mellitus type 2, high blood pressure and lipid metabolism disorders should be mentioned in particular.

Conservative therapies of severe obesity for weight reduction usually fail, which is why bariatric surgery is often the only treatment option for many patients, which not only leads to sustained weight loss, but also to a better quality of life, an improvement in the following diseases of obesity and an extension of life expectancy.

In many countries, obesity and metabolic surgery are therefore among the established medical procedures for weight reduction due to their proven effectiveness. Not, however, in Germany. There are two main reasons for this. Currently, only about 12,000 bariatric operations per year are performed in Germany, although around 4 million patients are eligible for bariatric surgery. If they were all to undergo surgery, the german health system would collapse economically. On the other hand, obesity and its treatment by surgery are stigmatised due to a lack of knowledge - also among doctors and other therapists. The patient's decision to undergo bariatric surgery is often ridiculed as his own failure, lack of willpower and a convenient alternative to exhausting, conservative weight loss.

However, the fact that conservative measures for weight reduction - a change in diet, exercise and behavioural therapy - fail in many cases is usually not due to unwilling patients, but rather to the sophisticated defence strategies of the human body when it comes to protecting existing fat reserves in the event of a negative energy balance (e.g. diet) and thus preventing a sustained reduction in weight.

Bariatric operations are often regarded as serious, high-risk procedures in which healthy organs are mutilated and the patient is crippled. In Germany, however, bariatric interventions are carried out under the eyes of medical associations.  According to the quality procedures of the German Society for General and Visceral Surgery, the procedures should only be performed at certified clinics or centres. The procedures are performed at these facilities in a standardised manner with low complication rates using the so-called minimally invasive technique.

And the effect of bariatric interventions is now well documented, as the New York Times commented in February 2017 as follows:

"Bariatric surgery is probably the most effective intervention we have in health care."

For patients with severe obesity, it is worth taking a closer look at bariatric surgery.  On the following pages, patients will find everything they need to know about obesity, its development, conservative and especially surgical treatment.

Bibliographical sources:

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Definition and Classification of Obesity

Obesity is defined as an abnormal increase in body fat, which usually leads to pathological changes. The so-called Body Mass Index (BMI) is usually used for classification:

According to the World Health Organization WHO, a BMI of 25.0-29.9 kg/m² is called pre-adipositive. As of a BMI of  ≥ 30 kg/m² an obesity disease is present, which is divided into different degrees of severity.

Classification	BMI [kg/m²]	Risk of second diseases
Under weight	< 18,5
Normal weight	18,5 - 24,9
Overweight/Preadipositas	25,0 - 29,9	slightly increased
Obesity grade I	30,0 - 34,9	increased
Obesity grade II	35,0 - 39,9	significantly increased
Obesity grade III	≥ 40	greatly enhanced

The BMI is quickly determined and thus allows a quick assessment of the nutritional status. However, it is not very meaningful for assessing the extent to which obesity leads to secondary diseases. Obesity alone is not decisive for secondary diseases, but also for the localisation of excessive body fat. Two patterns of fat distribution are distinguished in obesity:

 

1. Visceral obesity

In visceral form, also known as abdominal or central obesity, excessive body fat is located in the abdominal cavity. For a better visual understanding, this fat distribution is also called "apple type". The increase of visceral fat masses is a decisive risk factor for the development of cardiovascular diseases.

2. Subcutaneous obesity

In this form of obesity there is an increase in subcuteanous fat mass mainly in the area of the hips, buttocks and thighs, therefore the term "pear type" is used here.

Apple                                Pear

The fat distribution pattern in obesity can be determined by circumferential measurements. If the ratio of waist to hip is greater than 0.85 in women and greater than 0.90 in men, abdominal obesity is present; if the ratio is lower, peripheral obesity is assumed.

Bilbiography sources:

Lean ME, Han TS, Morrison CE (1995) Waist circumference as a measure for indicating need for weight management. BMJ 311: 158–161

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WHO Global InfoBase team (2005) The SuRF Report 2. Surveillance of chronic disease risk factors: country-level data and comparable estimates. World Health Organization.

Obesity - a Global Tsunami

A study published in 2014 revealed that around one-third of the world's population is overweight or obese, which is why the World Health Organization WHO is right to use the term "global epidemic of obesity".

In 1980, the total number of overweight or obese people worldwide increased from 875 million to 2.1 billion. According to the above-mentioned study, most obese people live in a total of 10 countries, including the USA, China, India and Germany. Extreme values are reached on the southern and western Pacific islands. In Micronesia, Tonga or the Cook Islands, for example, around 70% of the population is obese.

The Robert Koch Institute published a study in 2012 according to which 67% of all men and 53% of all women in Germany are overweight or obese. Between 2008 and 2011, 23% of German men and women have a BMI above 30 kg/m² and are therefore considered obese. The situation among children and young people has worsened considerably. Another study conducted by the Robert Koch Institute found that 15% of all children and adolescents are overweight or obese, which corresponds to around 800,000 obese children and adolescents in Germany.

If normal weight becomes a state of exception in some countries, obesity is no longer just a disease affecting an individual, but also a social problem with catastrophic consequences. While life expectancy is declining, mortality is increasing. The causes are the secondary diseases of obesity such as diabetes mellitus type 2, cardiovascular diseases, sleep-related respiratory disorders, tumour development and infertility. 

The economic burden on health systems from the obesity epidemic is also enormous. For example, in a study conducted by management consultants McKinsey in 2015, the costs of the epidemic are estimated at 1.6 trillion euros per year. Statistics on the incidence of overweight and obesity provide impressive evidence of the dramatic development of the disease in many parts of the world. Obesity is increasing rapidly in Asia, for example. As children and young people, in particular, are affected, the social threat posed by obesity is increasing massively.

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Ng M, Fleming T, Robinson M, et al. (2014) Global, regional, and national prevalence of overweight and obesity in children and adults during 1980 – 2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 384: 766–781

Bleich S, Cutler D, Murray C, Adams A (2008) Why is the developed world obese? Ann Rev Public Health 29: 273–295

WHO Global InfoBase team (2005) The SuRF Report 2. Surveillance of chronic disease risk factors: country-level data and comparable estimates. World Health Organization

Wirth A, Hauner H (2013) Adipositas Ätiologie, Folgekrankheiten, Diagnostik, Therapie. Springer, Berlin Heidelberg

McKinsey Global Institute (2014) Overcoming obesity: An initial economic analysis. http://www.mckinsey.com/mgi.

Why are we getting fatter?

Obesity is a chronic disease. The reason for this is a disturbed energy balance in which the energy intake through food outweighs the energy consumption.

Food and eating habits

With the beginning of the industrial revolution, our eating habits and food composition have changed.  Food is more or less always within reach and relatively inexpensive. It is also becoming more and more energy- and calorie-rich. 

Data from the National Health and Nutrition Examination Survey in the USA show that men increased their energy intake by 5 % and women by 15 % between 1976 and 1991, a development that was by no means limited to the USA but was also observed in other countries. Total daily energy intake from food also increased by almost 600 kcal between 1977 and 2003, due to the increase in the number of meals per day and portion sizes. 

The increase in sugar consumption, primarily from fruit juices and soft drinks, is particularly problematic. Traditional dietary patterns are no longer practised, more and more meals are taken outside the home and the consumption of high-calorie convenience meals is increasing.

Lack of exercise

In addition to changing our eating habits, physical activity has led to a significant decline in energy consumption. For example, the number of daily steps under modern living conditions is declining by around a third. A study of the Amish faith community in the USA as an example of a traditional way of life showed that women take an average of 15,000 steps and men approx. 21,000 steps per day. In a control group for modern lifestyles, the average number of steps per day was only 6,600 for women and around 7,000 for men, reducing energy consumption by around 500 kcal per day.

Changes in working conditions - less physical work, more sedentary work - and changes in leisure behaviour - television and computer behaviour - also result in a reduction in calorie consumption.

Genetic causes

The tendency to obesity may be due to genetic causes in individual cases. Obesity then already occurs in childhood, occasionally in combination with physical stigmata, hormonal disorders and occasionally also mental disability. The importance of genetic causes of obesity should not be overestimated.

Psychological causes

The development of obesity favoured by dietary and the lack of physical activity habits is further exacerbated by psychosocial causes. The disintegration of family structures (isolation) and changing demands in the job (work consolidation, unemployment) increase the feeling of stress, whereby the above-mentioned increase in energy supply can be intensified.

Hormonal causes

Hormonal disorders that lead to obesity, such as hypothyroidism or excessive cortisone production due to adrenal diseases, are usually overestimated. Appropriate blood tests can bring clarity.

Medications

Adipogenic drugs primarily include drugs that have an effect on the central nervous system, such as antidepressants. They stimulate hunger and appetite and can lead to considerable weight gain. Other drugs with similar effects include cortisone and insulin.

 

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Bleich S, Cutler D, Murray C, Adams A (2008) Why is the developed world obese? Ann Rev Public Health 29: 273–295

Duffey KJ, Popkin BM (2011) Energy density, portion size, and eating occasions: contributions to increased energy intake in the United States, 1977–2006. PLoS Med 8: e1001050

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Konturek SJ, Konturek JW, Pawlik T, Brzozowski T (2004) Brain-gut axis and its role in the control of food intake. J Physiol Pharmacol 55: 137–154 

Kumar R, Simpson CV, Froelich CA, et al. (2015) Obesity and deep brain stimulation: an overview. Ann Neurosci 22: 181–188 

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Rindi G, Leiter AB, Kopin AS, Bordi C, Solcia E (2004) The „normal“ endocrine cell of the gut: changing concepts and new evidences. Ann NY Acad Sci 1014: 1–12 

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Wyatt HR, Peters JC, Reed GW, et al. (2005) A Colorado statewide survey of walking and its relation to excessive weight. Med Sci Sports Exerc 37: 724–730

Diseases caused by Obesity

Obesity can lead to numerous diseases, including joint and lung diseases, cardiovascular problems, diabetes mellitus type 2, high blood pressure and lipometabolic diseases. Obesity also plays a role in the development of cancer. The life value of a 40-year-old obese person is shortened by 7 years on average.

Metabolic syndrome

Besides smoking, metabolic syndrome is regarded as a decisive risk factor for diseases of the arterial vessels, especially coronary heart disease. The so-called "deadly quartet" of metabolic syndrome includes:

•  Obesity, especially visceral type
• High blood pressure
• Lipometabolic disorders
• Insulin resistance or impaired glucose tolerance, the main cause of diabetes mellitus type 2

Other common diseases in metabolic syndrome are hyperuricemia (increase in uric acid levels, gout) and hyperandrogenemia in women, i.e. an increase in androgen levels (male sex hormone). Blood clotting disorders are also more common, which increases the risk of thrombosis in obese people.

Visceral obesity is an important factor in insulin resistance, in which the cells react less to insulin supplied from the body and from outside. Affected are mainly muscle, liver and fat cells. A study from 1997 showed a 6.2-fold increased risk of developing diabetes mellitus with an abdominal girth of more than 96.4 cm compared to less than 71 cm within 8 years. Conversely, even moderate weight loss in obesity can significantly reduce the risk of diabetes. This correlation does not apply to autoimmune diabetes mellitus type 1.

The most common consequence of obesity is high blood pressure, which occurs 5 times more frequently in obese people than in people of normal weight. Here, too, weight loss leads to a reduction in elevated blood pressure values. Obesity leads to an increase in triglycerides with simultaneous lowering of HDL cholesterol in the blood, which is called dyslipidemia. It is a precursor of arteriosclerosis (arteriosclerosis).

Obesity is an independent risk factor for cardiovascular diseases. These include heart failure, heart attack and sudden cardiac death as well as strokes.

Fatty liver

Visceral obesity can lead to liver obesity, which can range from inflammatory hepatitis to cirrhosis. Cirrhosis is a risk factor for the development of hepatocellular carcinoma.  Insulin resistance also plays an important role here.

Sleep-related respiratory disorders

Obesity can lead to the development of sleep apnoea syndrome, which is characterized by nocturnal breathing stops that can last for several minutes. Untreated, it leads to high blood pressure, heart problems, heart attacks, depression and stress disorders such as stomach ulcers, tinnitus and hearing loss. There too is a connection with the insulin resistance mentioned above.

Men are 4 times more likely to suffer from sleep apnoea syndrome than women. From a neck circumference of more than 43 cm in men and 40.5 cm in women, the risk of apnea syndrome increases significantly. The first sign of sleep apnoea syndrome is increased tiredness during the day.

Musculoskeletal system

Degenerative joint diseases occur more frequently and early in obesity. This often blocks the desired increase in physical activity during the treatment of obesity. Premature wear mainly affects the knee and hip joints, but spinal problems also increase.

Cancers

The risk of developing carcinoma is increased in obese people. The probability of developing a carcinoma is 12 - 50 % per increase in BMI of 5 kg/m², depending on the type of cancer. 

A link between obesity and tumours is known for colon, kidney, oesophagus, stomach, pancreas, liver and prostate cancer. Adipose women also have an increased risk of gallbladder and bile duct carcinoma, breast, ovarian and cervical cancer.

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Obesity and Psyche

Obesity is often associated with mental disorders. Among the German general population, 38% say they have suffered from a mental disorder in their lives to date, and around 48% of obese people. It is unclear whether obesity is the cause of mental illness or vice versa, but it is assumed that the illnesses influence each other and other factors also play a role.

In the obese population, the frequency of mental disorders varies greatly. Over 70% of obese patients seeking bariatric surgery have at least one mental disorder. Women with a high BMI are particularly susceptible. If conservative therapy (diet, exercise) is used to treat obesity, the frequency of mental disorders is significantly lower.

Stigmata - greedy, lazy and weak-willed

Stigmatizing attitudes towards obese people are widespread in society. Obese people are blamed for their obesity. They are often described as greedy, lazy and weak-willed and their overweight is regarded as a consequence of individual misconduct. Apart from negative or aggressive comments, obese people are often disadvantaged in educational institutions, in the workplace and in the health care system. People with stigmatisation develop a negative body image, experience a loss of self-esteem, become socially isolated and are exposed to an increased risk of depression and anxiety disorders. Against this background, the health-related quality of life of obese people is generally worse than in the general population.

Depression and anxiety disorders

Studies have shown the link between obesity and depression. Obesity is 55% more likely to develop depression than the general population. Here too, the greater the desire to lose weight, the more likely it is that those affected develop depression.  Conversely, the likelihood of developing obesity is increased by 58%.

Anxiety disorders are among the most common mental disorders in developed countries, affecting around 25% of the population at least once in their lives.  These include generalised anxiety disorders that are not fixed to a particular object or situation, panic disorders and phobias. For obese people, the risk of a co-existing anxiety disorder is increased by 40% and rises with increasing BMI.

Abuse and post-traumatic stress disorder (PTSD)

There is a clear link between physical and sexual abuse in childhood and the development of obesity. Studies show a 36% increase in the risk of developing obesity after childhood abuse.

Typical PTSD reactions are psychological reactions that occur against the background of a stressful event with an extraordinary threat, e.g. as flashbacks, nightmares, hyperexcitability or avoidance behaviour. 50% of all people with PTSD have visceral obesity. The likelihood of developing obesity as a result of PTSD is particularly high in women.

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