Lack of exercise is the main cause of the increase in obesity
Definition of obesity
In 2020, the WHO, the World Health Organization, continues to define overweight and obesity as “abnormal or excessive fat storage that can lead to health problems”. The WHO defines overweight as a BMI (body mass index) of > 25 kg/m². Obesity is present if the BMI > is 30 kg/m².
Other ways of assessing obesity are the Broca index (now surpassed by the BMI), waist circumference, hip circumference and the ratio of waist to hip circumference. If other methods for assessing the extent of obesity are not available, waist circumference plays a very important role, as this parameter correlates with health risks relating to metabolism and increased mortality. (Avenell et al: Systematic review of long-term effects and economic consequences of treatments for obesity and health implications for health improvement. health Technol Assess. 2004 may; 8(21): iii – iv, 1 – 182). In addition, there are many ways of drawing conclusions about the body’s fat content from the thickness of the skin folds in various parts of the body, although these have been described as difficult to reproduce.
The chapter on measuring body composition at the molecular level is dedicated to the chapter: Body composition. If obesity is characterized by abnormal or excessive fat storage, it is essential that fat mass is also used to characterize obesity. The fat mass index (FMI), which is described in a separate chapter, is suitable for this purpose. It also shows how the degrees of obesity can be defined with the help of this parameter.
Development of obesity
The proportion of overweight and obese children and adults is increasing at an epidemic rate worldwide. The attached figure shows the development of obesity for men in the USA and in Germany. The figures are taken from WHO statistics. In the meantime, women have overtaken men in the USA in terms of obesity, but still lag slightly behind men here in Germany.
Cultural factors obviously also have a significant influence on the frequency distribution between men and women. In Turkey, for example, 36.2 % of women are obese but only 22.2 % of men.
In 2014, only 36% of men in Germany had a BMI of less than 25 kg/m², while slightly more than half of women (51.4%) still did. For the USA: 21.2% of men and 37.1% of women have a BMI of less than 25 kg/m². These figures really make you wonder who the fashion industry is actually producing for – it’s completely missing the market!
Obesity is associated with diseases such as type II diabetes, lipometabolic disorders, high blood pressure and cardiovascular diseases, which carry a much higher risk of morbidity and mortality. Avenell et al. 2004 showed in a review that the risk of developing associated diseases decreases considerably with a reduction in obesity.
Why is the proportion of overweight and obese people increasing so much?
The most important factors influencing the development of obesity are calorie consumption and calorie intake, as it can generally be assumed that excess energy is stored in fatty tissue when the energy balance is positive. Calorie consumption is significantly influenced by muscle activity. Muscle mass also plays an important role in the basal metabolic rate.
The main reason for the increasing body weight of the population is the decrease in exercise! Our grandparents burned 3,000 to 5,000 calories a day during their physical work – on their walks, on Sunday family outings. Our ten fingers on the computer keyboard can’t compete with that! And certainly not our thumbs on our cell phones. And the range of tasty temptations has never been greater and more easily available to everyone; you don’t even have to stand in the kitchen for long!
According to figures from the Robert Koch Institute, the average calorie consumption through physical activity in Germany was 30 – 35 METs per week, i.e. 4 – 5 METs per day. This means that the calorie consumption is 24 METs per day for the basal metabolic rate and less than 30 METs per 24 hours.
METs x body weight equals the calories consumed. If someone does intensive sport twice a week (1.5 hours, 600 kcal/h), they are doing quite a lot! The additional calories of just under 2000 Kcal per week add up to around 285 Kcal per day. However, this is nowhere near the calorie consumption of a farmer in 1950.
As children today are already moving less and less and therefore developing less muscle, they often become obese even with a largely normal calorie intake and are therefore candidates for all facets of metabolic syndrome.
What to do?
Increasing calorie consumption through physical activity is a very important factor in combating the risk factor of obesity. There is no other place where the importance of sports science for the health and well-being of the population can be demonstrated so emphatically.
However, if you want to work out the positive influence of exercise on the risk profile, you cannot simply measure body weight. Rather, it is essential to differentiate between body fat tissue and fat-free body mass, a high percentage of which is formed by the muscles. (see body composition)
In addition to the extra calories burned through exercise, diet is also very important. With so many dietary recommendations, it is not easy to distinguish between really good advice and complete nonsense. If you look at the “nutrition scene” for more than 45 years, you will see that even the actual experts often have changing opinions, although at least some of these can be attributed to new studies. In general, it is probably true that carbohydrates should continue to make up the largest proportion of our calorie intake. However, the proportion of free sugars – such as sucrose and fructose – should be significantly reduced. The chapter on nutrition follows, but initially has a somewhat lower priority on this homepage.