Weight status

1. Key messages

Weight excess is an important problem in Belgium like in most industrialized countries.
In 2013, 48% of the adult population was suffering from overweight; this includes a share of 14% being obese, which is close to the EU-15 mean. Obesity is strongly related to the socio-economic status with a much higher prevalence among people with the lowest educational level. The obesity prevalence is higher in Wallonia than in the other regions, particularly in men. Obesity prevalence has been increasing in Belgium since 1997, but this tendency seems to have stabilized, except for men in Wallonia.
In 2014, 14% of the adolescents were suffering from overweight (including those who are obese). Overweight is more frequent in boys (16% vs 12% in girls), more frequent in the region of Wallonia (15% vs 13% in the Flemish region), and more frequent in families with a lower income.

2. Background

Overweight and obesity are defined as an excessive accumulation of body fat, which favours the development of chronic diseases (diabetes type 2, cardiovascular diseases, cancers). The Body Mass Index (BMI), calculated as the weight divided by the square of the height, is a simple tool allowing to classify the weight status into broad categories: underweight, normal weight, overweight and obesity. In adults, overweight and obesity are defined as BMI ranges of 25-30 and ≥30, respectively. In children and adolescents, the boundaries of the BMI categories are age and sex specific.

The weight status can be derived either from self-reported information, such as that collected from the Health Interview Survey (HIS) and the Health Behavior in School-aged Children survey (HBSC), or from measured information such that collected during the Food Consumption Survey (FCS). Self-reported data usually lead to some underestimation of the true overweight/obesity prevalence.

We will focus on the obesity prevalence in adults (HIS data) and the overweight prevalence in adolescents (HBSC data). Choices were driven by the possibility to analyze trends and to make international comparisons.

According to the HIS of 2013 (self-reported data) [1]:

  • 48% of the adult population had an excess of weight (14% obese and 34% overweight);
  • 49% had a normal weight; and
  • 3% were underweight.

But according to the Food Consumption Survey of 2014 (measured data) [2], the prevalence reaches up to 53% of the population aged 18-64 (with 19% obese and 34% overweight), 45% had a normal weight and 2% were underweight.

3. Obesity in adults

Belgium

According to the Health Interview Survey, the prevalence of obesity in adults was 14% in 2013, without any difference between genders.

The prevalence of obesity increases with age until the age of 65-74 years; it then decreases again among 75 years and older. This increase starts earlier in women (25-34) than in men (35-44). The percentage of obese people varies from 3.9% at the younger age group (18-24) up to 19.6% at the age-group 65-74.

Prevalence of obesity by age group and sex, Belgium, 2013
Source: Health Interview Survey, Sciensano, 2013 [1]

Evolution over time and by regions

The percentage of obese adults in Belgium increased until 2008 and stabilized afterwards.

Obesity prevalence has been higher in Wallonia than in the other regions, in all the successive HIS for both sexes; the excess is more pronounced in men.

From 1997 to 2013, the prevalence of obesity among men has increased moderately in Flanders and more seriously in Wallonia and Brussels. In women, it has increased moderately in all regions. As the long-term Federal Vision on Sustainable Development aims at a decrease of the share of obese adults, efforts are still needed.

  • Men
  • Women

Prevalence of obesity among men aged 18 and over, by region of residence and for Belgium, 1997-2013
Source: Health Interview Survey, Sciensano, 1997-2013 [1]

Prevalence of obesity among women aged 18 and over, by region of residence and for Belgium, 1997-2013
Source: Health Interview Survey, Sciensano, 1997-2013 [1]

By educational level

Obesity prevalence is strongly associated with educational level. In 2013, there were three times fewer obese people among the most educated (7.7%) compared to the less educated (23.5%). This difference between education groups has increased as compared to previous HIS survey (in 2008 the ratio was 2).

Prevalence of obesity among people aged 18 and over by level of education, Belgium, 2013
Source: Health Interview Survey, Sciensano, 2013 [1]

International comparison

The prevalence of obesity in Belgium used to be higher than the EU-15 mean since 2000, but it has been increasing slower since 2008. So, in 2015 and for both sexes, Belgium ranks better and the prevalence of obese adults is lower than the EU-15 mean.

  • Men
  • Women

Prevalence of obesity among men aged 18 and over, by country of residence (EU-15), 2015 or nearest year
Source: OECD Health statistics, 2015 or nearest year [3]

Prevalence of obesity among men aged 18 and over, by country of residence (EU-15), 2015 or nearest year
Source: OECD Health statistics, 2015 or nearest year [3]

4. Overweight in adolescents

Belgium

According to the Health Behaviour in School-aged Children (HBSC) survey of 2014, boys are more frequently suffering from overweight than girls in Belgium; this is observed in each of the specific ages under study (11, 13 and 15 years). Overweight tends to increase with age (but differences are not significant).

Prevalence of overweight in adolescents, by sex and age, Belgium, 2014
Source: Unweighted Belgian average based on the Health Behaviour in School-aged Children survey (IOTF cut-off), 2014 [4,5]

Evolution over time by region

Overweight prevalence among 15-year-old adolescents is higher in the French than in the Flemish speaking community.

The prevalence of overweight among 15-year-old adolescents consistently increased between 2006 and 2014, both in boys and in girls, for the whole of Belgium.

Among 15-year-old boys, the overweight prevalence increased slightly along the successive surveys, in each of the two communities. Among girls, it increased in the Flemish-speaking but not in the French speaking community. The differences between regions are less pronounced in 2014, compared to 2006, for both sexes.

  • Boys
  • Girls

Prevalence of overweight (including obesity) among 15-year-old adolescent boys, by community, 2006-2014
Source: Health Behaviour in School-aged Children survey (IOTF cut-off), 2006-2014 [4,5]

Prevalence of overweight (including obesity) among 15-year-old adolescent girls, by community, 2006-2014
Source: Health Behaviour in School-aged Children survey (IOTF cut-off), 2006-2014 [4,5]

By socio-economic status

According to the HBSC report, higher overweight prevalence was associated with low family affluence for both sexes. These social inequalities result in a 10 percentage-point difference in the Flemish part and a 15 percentage point-difference in the French part of the country in 2014.

International comparison

Belgium ranks quite favorably among the EU-15 countries with an overweight prevalence of 16% compared to 18% for the EU-15 average in boys. The prevalence of overweight is similar to EU-15 average (12%) among girls.

  • Boys
  • GIrls

Prevalence of overweight (including obesity) among 15-year-old adolescent boys, by country of residence (EU-15), 2014
Source:  OECD Health at a glance, 2017 [6]

Prevalence of overweight (including obesity) among 15-year-old adolescent girls, by country of residence (EU-15), 2014
Source: OECD Health at a glance, 2017 [6]

5. Read more

View the metadata for this indicator

HISIA: Interactive Analysis of the Belgian Health Interview Survey

Definitions

Body mass index
The body mass index (BMI) is a measure of a person’s weight relative to their height that links fairly well with body fat. It is calculated as a person’s weight (in kilograms) divided by the square of his or her height (in meters): BMI = weight (kg) / height (m²). In adults, overweight and obesity are defined as BMI ranges of 25-30 and ≥30, respectively. In children and adolescents, the boundaries of the BMI categories are age and sex specific.
EU-15
The EU-15 corresponds to all countries that belonged to the European Union between 1995 and 2004: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, Sweden and the United Kingdom. We compare the Belgian health status to that of the EU-15 because these countries have similar socioeconomic conditions.

References

  1. Health Interview Survey, Sciensano, 2013. https://his.wiv-isp.be/fr/Documents%20partages/NS_FR_2013.pdf
  2. Food Consumption Survey, Sciensano, 2014. https://fcs.wiv-isp.be/FR/SitePages/Accueil.aspx
  3. OECD Health statistics. http://stats.oecd.org/
  4. HBSC Surveys, 2006-2014. http://www.hbsc.org/publications/international/
  5. International Obesity Task Force. https://www.worldobesity.org/about/about-obesity/obesity-classification
  6. OECD Health at a Glance 2017. http://www.oecd.org/health/health-systems/health-at-a-glance-19991312.htm