Definition of pre-obesity and obesity

Pre-obesity (overweight) and obesity are medical conditions marked by an abnormal and/or excessive accumulation of body fat that presents a risk to health ( WHO 2019 ). Obesity is a chronic relapsing disease ( WHO 2022 )(pdf), which in turn acts as a gateway to a range of other non-communicable diseases, such as diabetes, cardiovascular diseases and cancer.

The Body Mass Index (BMI), is a measure of a person’s weight relative to height that correlates fairly well with body fat. It is calculated by dividing a person’s weight in kilograms by the square of the person’s height in metres (kg/m²) is commonly used to indicate underweight, normal weight, overweight and obesity (WHO, Eurostat ).

An adult is categorised as underweight if the BMI is below 18.5 kg/m2, normal weight if the BMI is in the range of 18.5 to 24.9 kg/m², to have pre-obesity, also referred to as overweight, if their BMI is in the range of 25 to 29.9 kg/m², and having obesity if the BMI is 30 kg/m² or higher (WHO). Adult BMI categories are independent of age and sex.

Accumulation of abdominal fat mass is referred to as abdominal, central or visceral obesity (WHO 2008). Waist circumference and waist-to-hip-ratio to-hip-ratio are measures of abdominal obesity. Central obesity is associated with higher risk of co-morbidities such as coronary heart disease and type 2 diabetes. Abdominal fat can vary considerably within a narrow range of total body fat and body mass index. There are sex-specific cut-off points for waist circumference and waist-to-hip-ratio in defining abdominal obesity (WHO 2008).

Obesity and pre-obesity can also be identified in children using BMI; however, the range does not apply in all ages. BMI for children is interpreted in relation to their age and sex as adipose tissue distribution varies significantly.

In pre-school children aged 0-5 years, pre-obesity and obesity are defined as the proportion of children with a sex- and age-specific body mass index-for-age value above +2 z-score and above +3 z-scores of the 2006 WHO recommended Growth Standards, respectively.

In school age children and adolescents aged 5-19 years, pre-obesity and obesity are defined as the proportion of children with a sex- and age-specific body mass index for-age value above +1 Z-score, and above +2 Z-scores of the 2007 World Health Organization recommended Growth Reference respectively (EC 2014)(pdf).

Alternative ways of assessment such as arm circumference-for-age, triceps and subscapular skinfold measurements are also applied in young children (WHO 2007)(pdf).

Prevalence of pre-obesity and obesity in Europe

59% of adults were estimated to have pre-obesity and obesity and 23% obesity in the European Union in 2016, based on data obtained from population based studies where height and weight were measured ( OECD 2019 ).

Measured obesity data are considered less problematic and more reliable than self-reported data. Self-reported prevalence of obesity in 2014 data can be found here: Eurostat 2016 (pdf).

The prevalence of obesity in children (5-9 years) and adolescents (10-19 years) is summarised in Table 2 (World Obesity Federation 2019)(pdf). 

Table 1: Prevalence of obesity in adults in the EU in 2016

Table 2: Prevalence of obesity in children and adolescents in the EU in 2016

View visualisation: Prevalence of obesity in adults in the EU in 2016 map

View visualisation: Prevalence of obesity in adults in the EU in 2016 chart

Factors related to obesity

Obesity is a multifaceted health condition that is influenced by genetic, behavioural, physiological, psychological and social factors (IARC 2017, EuroHealth 2019, WHO 2000 , OECD 2019, CDC 2011).

Environmental factors such as exposure to compounds in diets, air, water etc can induce epigenetic changes, which in turn may influence an individual’s appetite, satiety, metabolism and body fat distribution, which subsequently can contribute to overweight and obesity ( AIHW 2018 ).

Table 4 presents modifiable risk factors related to pre- obesity and obesity and the nature of relationship between these factors and obesity.

Table 4: Modifiable risk factors related to obesity as described by health-related organisations 

Disease and economic burden related to pre-obesity and obesity

According to the Global Burden of Disease 2019 study, high BMI was associated with more than 583 thousand all-cause deaths in the European Union countries in 2019 (GBD 2019 results tool). Moreover, more than 14 million Disability Adjusted Life Years (DALYs) were attributed to high BMI.

The total cost of adult obesity in the EU was estimated at 70 billion Euro per year in 2016 including healthcare costs and lost productivity. About 7% of the national budgets across the EU is spent on non-communicable diseases associated with obesity every year (EC 2014).

Pre-obesity and obesity contribute to the development of other non-communicable diseases and lower life expectancy and quality of life (WHO 2006). At the same time, they negatively impact labour market output in four ways: through higher levels of absenteeism, presenteeism, early retirement, and lower employment rate (OECD 2019).

In the EU in 2016 it is estimated to have costs of USD Purchasing Power Parity 781 per capita per year because of reduced labour market productivity from pre-obesity or obesity.

According to the model predictions, obesity-related absenteeism, presenteeism and unemployment will decrease labour market output by 0.37%, 0.80% and 0.42% respectively (OECD 2019). Similarly, early retirement, due to pre-obesity and obesity, will decrease the labour market productivity by 0.05% (OECD 2019).

View visualisation: Disability Adjusted Life Years attributed to high Body Mass Index map

View visualisation: Mortality attributed to high Body Mass Index map 

Policy recommendations on prevention of obesity

Many EU Member States have in place strategies and national guidelines for the primary prevention of pre-obesity and obesity (EC 2018).

Such strategies and guidelines include national dietary guidelines, physical activity guidelines, provision of information to the population through food and menu labelling, public awareness campaigns, and mobile apps, that empower the population to make healthier choices (EC 2018, GBD 2015, WHO 2007) (53).

Many countries have also action plans to specifically tackle childhood obesity (OECD 2019). The EU Action Plan on Childhood Obesity 2014-2020 endorses a healthy start in life, restrict marketing and advertising to children, promote healthier environments in school and pre-schools, and make healthy options the easy options ( EC 2014 ). The Commission on Ending Childhood Obesity identifies three critical periods during a life course, preconception and pregnancy, infancy and early childhood and older childhood and adolescence, where consideration should be taken for preventing obesity (WHO 2016).

The 2007 European Commission’s White Paper on Strategy for Europe on Nutrition, Overweight and Obesity-related Health issues recommends availing healthy choices such as promotion of fruits and vegetables in schools and promotes sustainable urban transport actions-encouragement of walking and cycling projects (EC 2007).

Moreover, the revision and follow-up of the 2014-2020 EU Action Plan on Childhood Obesity, as well as raising awareness and working on the prevention of obesity among other factors that are related to cancer, is a significant part of Europe's Beating Cancer Plan.  

Primary Prevention programmes and policy recommendations related to the consumption of fats, fruit and vegetables, sugars and sweeteners, whole grain, and alcoholic beverages as well as to physical activity and sedentary behaviour are listed in the relevant chapters of this Health Promotion and Disease Prevention Knowledge Gateway.

Best practices of obesity prevention can be obtained from the repository of the Best Practice Portal of the European Commission website.