1. Key messages
- In 2018, more than half of the adult Belgian population was affected by overweight and 16% was affected by obesity.
- People affected by overweight and obesity have higher healthcare costs and a higher number of days absent from work than people with a healthy weight.
- In 2018, almost 2 billion Euros were spent on healthcare costs related to overweight.
- Healthcare costs related to obesity amounted to 1.5 billion Euros in 2018.
2. Cost of overweight and obesity
In Belgium, as in many high-income countries, average body mass index (BMI) has increased over the past decades among both children and adults. According to the Belgian health examination survey in 2018, more than half of the adult population was affected by overweight and 16% was affected by obesity . People with overweight and obesity have reportedly a higher risk of developing many chronic diseases, like cardiovascular disease, type 2 diabetes, kidney diseases, and cancer. Being exposed to these different conditions is likewise strongly associated with increased healthcare and medication spending and decreased workforce productivity.
With the aim of highlighting the important and growing impact of overweight and obesity in Belgium, we estimated the cost of hospitalizations, ambulatory visits, and use of medication (direct healthcare costs) and the cost of absenteeism from work (indirect costs) of people with overweight and obesity .
People with overweight have 24% higher costs than people with healthy weight
We estimated that every year overweight has an impact on the healthcare cost of around €651 for each person that is affected by overweight. At national level, this corresponded to €1,864,464,355 in 2018. In addition to the costs related to a higher number of hospitalization, ambulatory care and use of medication, people affected by overweight were found to have a higher number of days absent from work. The absenteeism cost around €242 per capita every year. The total cost of absenteeism related to overweight corresponded to €320,082,750 in 2018.
People with obesity have 36% higher costs than people with healthy weight
The yearly healthcare cost of people with obesity was estimated to be around €1,015 per capita. At national level, the healthcare cost for the Belgian population affected by obesity was €1,464,742,302 in 2018. People affected by obesity also had a significantly higher cost due to work absenteeism. The total cost of absenteeism related to obesity corresponded to €889,469,387 in 2018.
Source: Gorasso et al. 
Hypertension, high cholesterol, and depression are the major contributors to healthcare costs
We were interested in investigating which chronic conditions contribute the most to the direct healthcare costs of overweight and obesity among adults. The cost of hypertension was by far the highest contributor to higher healthcare costs related to overweight and obesity. The second highest relative cost was attributed to high cholesterol followed by serious gloom and depression.
Source: Gorasso et al. 
3. Read more
- Body Mass Index (BMI)
- It is a measure of body fat based on height and weight that applies to adult men and women. It is commonly used in observational studies to define weight status. According to the World Health Organization, a person has a healthy weight if the BMI is between 18.5 and 25. Overweight is defined as having a BMI between 25 kg/m² and 30 kg/m² and obesity is defined as having a BMI higher than 30 kg/m².
- Costs related to overweight and obesity
- Our study includes only adults. The costs are adjusted for age, gender, household educational level and the lack of physical activity. These variables are known to affect either the probability of being overweight or obese or the probability of having higher costs. The adjusted costs represent a more conservative estimate than the unadjusted ones. This means that some of the costs that we see for each individual might be attributed to the fact that for example individuals are older, or have an unhealthy lifestyle. By adjusting these costs we can “filter out” the effect of these elements and have a clearer understanding of the sole impact of overweight or obesity.
- Direct healthcare cost
- Direct healthcare costs include all expenses related to hospitalizations, ambulatory visits and use of medication. These costs can be directly paid by the health insurance, reimbursed to patients after payment, or are out-of-pocket. Information on direct healthcare costs is made available by the intermutualistic agency (IMA), which collects the healthcare expenses of all public health insurances in Belgium.
- Indirect cost
- In this study, indirect cost include the cost related to being absent from work for medical reasons. Through the Belgian Health Interview Survey, we had information on the number of days a person is absent from work for medical reasons. Indirect costs were computed multiplying the number of days with the average daily wage in Belgium in 2018.
- Health Interview Survey. Sciensano. 2018. https://www.sciensano.be/en/projects/health-interview-survey.
- Gorasso, V., Moyersoen, I., Van der Heyden, J. et al. Health care costs and lost productivity costs related to excess weight in Belgium. BMC Public Health, 2022. https://doi.org/10.1186/s12889-022-14105-9