Does the Urban Environment Influence the Risk of Obesity

[This article has been published in Catalan by the Diputació de Barcelona]

Obesity is defined as an excessive or abnormal accumulation of fat which can affect our health

Obesity is defined as an excessive or abnormal accumulation of fat which can affect our health. The Body Mass Index, based on a formula involving the individual’s height and weight (kg/m²), is used to determine whether an adult is obese. Adults with a BMI of 25 kg/m² or higher are considered to be overweight and obese when it is 30 kg/m2 or higher.  However, healthy weight in children is assessed using reference tables according to age and sex.

39% of adults are overweight or obese. This figure has tripled since the 1970s

According to the World Health Organisation, 39% of adults are overweight or obese. This figure has tripled since the 1970s. The problem is equally worrying in children. According to the findings of the INMA and HELIX studies coordinated by ISGlobal, the prevalence of overweight and obesity among children living in the Barcelona metropolitan area (the study was carried out in Sabadell) is 30%, with more overweight boys than girls. These figures are double those reported for France and Norway in a recent WHO report, which indicated that the highest rates of childhood obesity in Europe are found in southern European countries.

Causes and Consequences of Obesity

The concept has recently emerged of an obesogenic environment, that is, an environment that increases our risk of becoming overweight

The main cause of obesity is an imbalance between consumption and expenditure of energy, that is, between what we eat and the energy we expend in physical activity. However, many studies have concluded that our choices are influenced by multiple factors and the concept has recently emerged of an obesogenic environment, that is, an environment that increases our risk of becoming overweight.  Some of these factors are social or educational, such as exposure to advertisements for unhealthy foods.

Excess weight causes many health problems, notably cardiovascular disease and diabetes. Some types of cancer are associated with overweight, such as breast and colon cancer.

Children are also affected, both physically and emotionally, by obesity and overweight and being fat has a negative impact on their quality of life. Furthermore, overweight and obese children have a greater risk of becoming obese adults.

What Can We Do?

One good practice is to choose active transportation, in other words, walking or cycling to school or the workplace

The best way to combat obesity is to adopt  a healthy lifestyle, which involves increasing our consumption of fruits and vegetables, reducing our consumption of highly processed foods and empty calories (such as soft drinks and snacks), and engaging in regular physical activity. Recommendations specify a minimum of 30 minutes activity per day for adults and 60 minutes per day for children. One good practice is to choose active transportation, in other words, walking or cycling to school or the workplace.  It is also very important to get enough sleep.

Anyone looking for advice about how to achieve a healthy weight should contact a health professional, such as a doctor or dietician-nutritionist.

The results of many of our studies indicate that pregnancy is a common starting point for excessive weight gain

The results of many of our studies indicate that pregnancy is a common starting point for excessive weight gain. It is very important, therefore, that women seeking to become pregnant should plan ahead, start their pregnancy at a healthy weight, and gain an appropriate amount of weight during pregnancy following the recommendations of their doctor or midwife.

Obesity and the Urban Environment

In urban areas where (...) people are more likely to be physically active, there are less likely to gain excess weight

Over the last decade, many studies have sought to identify factors in the urban environment that influence our health in general and the risk of obesity in particular. The findings of this research suggest that in urban areas where people can walk safely and have better access to shops, services and public transport, they are more likely to be physically active and, therefore, less likely to gain excess weight. Furthermore, such urban areas encourage people to use active modes of transport and it has been shown that this is a good way of preventing obesity in children and in the adult population. The urban environment can also increase the risk of obesity. Research undertaken in the United States and the United Kingdom, for example, has found evidence of a link between the number of fast food restaurants in the built environment and childhood obesity in the population.

Research undertaken in the US and the UK has found evidence of a link between the number of fast food restaurants and childhood obesity

But a great deal of research remains to be done because there are many more factors relating to the urban environment that have not, as yet, been studied in depth or have been studied only in countries, such as the United States, where the cities are very different from those in Europe.    

For this reason, ISGlobal is currently undertaking research with projects such as the ECHOCAT study, funded by TV3’s Fundació la Marató, to investigate how the urban environment influences the risk of obesity in schoolchildren.   The ECHOCAT study takes into account different factors, such as air pollution, exposure to noise, ease of access to green spaces and public transport, food environment, etc.  

We are also taking part in European studies (LifeCycle and STOP) which will allow us to compare our results with those of research in other countries.

If the results of this research eventually demonstrate that the design of our cities (including access to green spaces, streets where people can walk safely, access to public transport...) influences the risk of obesity, local and central governments will be obliged to take a more proactive approach towards designing healthier cities.

It is therefore important that researchers continue to work to identify the factors that favour weight gain and to look for ways to reduce this risk

Excess weight gain is a major problem affecting children and adults which leads to many health problems and a reduced quality of life. It is therefore important that researchers continue to work to identify the factors that favour weight gain and to look for ways to reduce this risk. To successfully combat the problem, we need the general public to engage by moving towards more healthy lifestyles and we need commitment from government institutions, who should develop and implement appropriate urban planning policies