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.

Bilbiography sources:

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.

 

Bilbiography sources:

Bassett DR, Schneider PL, Huntington GE (2004) Physical activity in an Old Order Amish community. Med Sci Sports Exerc 36: 79–85

Briefel RR, McDowell MA, Alaimo K, et al. (1995) Total energy intake of the US population: the third National Health and Nutrition Examination Survey, 1988–1991. Am J Clin Nutr 62 (5 Suppl): 1072S–1080S

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

Hussain SS, Bloom SR (2013) The regulation of food intake by the gutbrain axis: implications for obesity. Int J Obes 37: 625–633 

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 

Nielsen SJ, Popkin BM (2003) Patterns and trends in food portion sizes, 1977–1998. JAMA 289: 450–453

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 

Schwartz MW, Woods SC, Porte D Jr, Seeley RJ, Baskin DG (2000) Central nervous system control of food intake. Nature 404: 661–671

Stengel A, Taché Y (2011) The physiological relationships between the brainstem, vagal stimulation, and feeding. In: Preedy VR, Watson RR, Martin CR (Hrsg) Handbook of Behavior, Diet and Nutrition. Springer, New York Dordrecht Heidelberg London, pp 817–828

Wiegand S, Krude H (2015) Monogene und syndromale Krankheitsbilder bei morbider Adipositas. Internist 56: 111–120

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