Adults who are obese and commute by car are at a 32% increased risk of death from any cause, compared with normal-weight peers who walk or cycle to work, report researchers. The finding, which was recently presented at this year’s European Congress on Obesity, was based on an analysis of more than 160,000 British individuals.
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For the study, researchers from the British Heart Foundation examined data from 163,149 people (aged between 37 and 73 years) who provided information about whether they drove to work, walked and cycled (active-mixed), only cycled or only walked, as part of a UK Biobank study.
Previous assessments of UK Biobank data have found that active modes of commuting such as cycling or walking were associated with a 50% decreased the risk of death, compared with commuting by car.
A 32 percent difference in premature death
Given that in the UK, 57% of men and 66% of women in the UK are overweight or obese, lead investigator Carlos Celis and colleagues investigated whether different ways of commuting to work may have an impact on the link between obesity and adverse health outcomes.
Obesity was defined as a body mass index (BMI) of more than 30 and the health outcomes being assessed were death from any cause, death due to heart disease and hospital admission due to non-fatal heart disease.
At the congress, Celis reported that a total of 2,425 participants died and 7,973 developed heart disease over a mean follow-up period of five years.
Compared with normal-weight individuals who had an active-mixed commute, obese people who drove to and from work were at a 32% increased risk for premature death, a two-fold increased risk for heart disease and an almost 60% increased risk for non-fatal heart disease.
By contrast, obese individuals who said they had an active commute were found to be at a similar risk for death from any cause as normal-weight active commuters, suggesting that an active commute could decrease the detrimental health effects of being obese.
However, obese people who had an active commute were still at an 82% increased risk for heart disease, compared with normal-weight individuals who also had an active commute.
Active commutes are easily ‘fitted within our daily routines’
The study’s lead author, Edward Toke-Bjolgerud, says the results suggest people who are overweight or obese could decrease the risk of premature death if they walked or cycled to work. U.S studies have reported similar adverse health outcomes associated with overweight or obesity.
The findings are not new. A 2013 study conducted by researchers at Harvard T.H. Chan School of Public Health and the University of Cambridge found that each five-unit increase in BMI (from 30 to 35, for example) was associated with a 49% increased risk for death from cardiovascular disease, a 38% increased risk for death from respiratory disease and a 19% increased risk for death from cancer.
The authors of the current study say that irrespective of body weight, engaging in physical activity could partly reduce the health risks associated with obesity.
The authors conclude:
Our findings, if causal, suggest that people with overweight or obesity could potentially decrease the risk of premature mortality if they engage in active commuting.
However, compared to other forms of physical activity - such as gyms and exercises classes - active commuting can be implemented and fitted within our daily routines, often with no additional cost, but at the same time could increase our overall physical activity levels and therefore help to meet the current physical activity recommendations for health.”