Obesity and overweight are leading risk factors for chronic diseases

Key facts

• Obesity is one of the greatest public health challenges of the 21st century. Its prevalence has tripled in many countries of the WHO European Region since the 1980s. And the numbers of those affected continue to rise at an alarming rate.
• In 2008, more than 1.4 billion adults, 20 and older, were overweight. Of these over 200 million men and nearly 300 million women were obese.
• 35% of adults aged 20 and over were overweight in 2008, and 11% were obese.
• 65% of the world’s population live in countries where overweight and obesity kills more people than underweight.
• More than 40 million children under the age of five were overweight in 2011.
• Obesity is preventable.
• Obesity causes various physical disabilities and psychological problems.
• Excess weight drastically increases a person’s risk of developing a number of noncommunicable diseases (NCDs), including cardiovascular disease, cancer and diabetes.
• Overweight and obesity are linked to more deaths worldwide than underweight.
• 65% of the world’s population live in countries where overweight and obesity kill more people than underweight (this includes all high-income and most middle-income countries).

What causes overweight and obesity?

Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.

Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2).

The WHO definition is:

a BMI greater than or equal to 25 is overweight
a BMI greater than or equal to 30 is obesity.
BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.

The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. Globally, there has been:

– An increased intake of energy-dense foods that are high in fat; and
– An increase in physical inactivity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanization.
– Changes in dietary and physical activity patterns are often the result of environmental and societal changes associated with development and lack of supportive policies in sectors such as health, agriculture, transport, urban planning, environment, food processing, distribution, marketing and education.

Chronic systemic ‘Metainflammation’ in Obesity

Molecular Biology of Obesity

It is increasingly accepted that chronic inflammation is a feature of obesity. Obesity-induced inflammation triggers enhanced recruitment of macrophages into the adipose tissue.

What are health consequences of overweight and obesity?

Raised BMI is a major risk factor for noncommunicable diseases such as:

– Cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2008;
diabetes;
– Musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints);
some cancers (endometrial, breast, and colon).
– The risk for these noncommunicable diseases increases, with the increase in BMI.

Childhood obesity is associated with a higher chance of obesity, premature death and disability in adulthood. But in addition to increased future risks, obese children experience breathing difficulties, increased risk of fractures, hypertension, early markers of cardiovascular disease, insulin resistance and psychological effects.

How can overweight and obesity be prevented?

Overweight and obesity, as well as their related noncommunicable diseases, are largely preventable. Supportive environments and communities are fundamental in shaping people’s choices, making the healthier choice of foods and regular physical activity the easiest choice (accessible, available and affordable), and therefore preventing obesity.

Physical activity and diet

Participation in 150 minutes of moderate physical activity each week (or equivalent) is estimated to reduce the risk of ischaemic heart disease by approximately 30%, the risk of diabetes by 27%, and the risk of breast and colon cancer by 21–25%. Physical activity also lowers the risk of stroke, hypertension and depression.

Country estimates of 2008 revealed that approximately 35% of all people in the WHO European Region are insufficiently physically active. Men were more active than women, particularly in high-income countries, where nearly every second woman was insufficiently physically active. The increased automation of work and other aspects of life in higher-income countries is a likely determinant of insufficient physical activity.

The Health Behaviour in School-aged Children (HBSC) 2005/2006 survey of countries in the WHO European Region and North America found that girls across all countries and age groups report being less active than boys, with the gender gap increasing with age. The survey found that in general 15-year-olds (average 16%) were less likely to report meeting the physical activity guidelines than 11-year-olds (average 26%) in the majority of countries. Only 22% of 11-year-old girls report engaging in moderate-to-vigorous physical activity for at least 60 minutes per day. For boys, the figure is 30%.

Socioeconomic status

Family affluence was significantly associated with overweight or obesity in around half of the countries surveyed in the HBSC study: those from lower affluence families were more likely to be overweight or obese. This pattern was strongest in western Europe.

A daily breakfast and at least daily fruit consumption are seen as two of the most important healthy eating habits. In the HBSC study, eating breakfast daily was significantly associated with higher family affluence in the majority of countries for boys and over half for girls. Similarly, low family affluence was significantly associated with lower levels of fruit consumption among boys and girls in the majority of countries surveyed.

Lifestyle Changes at the individual level:

– Limit energy intake from total fats and sugars;
– Increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts;
engage in regular physical activity (60 minutes a day for children and 150 minutes per week for adults).
– Individual responsibility can only have its full effect where people have access to a healthy lifestyle. Therefore, at the societal level it is important to:

Medical doctors and health professionals should support individuals in following the recommendations above promoting regular physical activity and healthier dietary choices.

The food industry can play a significant role in promoting healthy diets by:

– Reducing the fat, sugar and salt content of processed foods;
– Ensuring that healthy and nutritious choices are available and affordable to all consumers;
– Practicing responsible marketing especially those aimed at children and teenagers;
– Ensuring the availability of healthy food choices and supporting regular physical activity practice in the workplace.
WHO response

ESPREVMED is supporting health professionals and the public to improve availablity of affordable and easily accessible healthy food and physical activity – especially the poorest individuals.

Adopted by the World Health Assembly in 2004, the WHO Global Strategy on Diet, Physical Activity and Health describes the actions needed to support healthy diets and regular physical activity. The Strategy calls upon all stakeholders to take action at global, regional and local levels to improve diets and physical activity patterns at the population level.