Obesity is a global health crisis. The World Health Organisation (WHO) warns that obesity can lead to a range of noncommunicable diseases including type 2 diabetes, cardiovascular disease, hypertension, stroke, various forms of cancer and mental health issues.
Having a high BMI is said to account for 60% of the risk of developing type 2 diabetes and 20% of hypertension and coronary-heart disease.
Consumption of processed and fast food, trans fatty acids (TFAs), and sugar, combined with increasing portion sizes and decreased physical activity all accounts to high levels of obesity.
There are many causes of obesity, but could air pollution also increase your risk? Here we take a closer look.
Obesity among women
Researchers from the University of Michigan have found that air pollution may affect weight, body mass index, waist circumference and body fat.
In the study, a total of 1,654 women from the Study of Women’s Health Across the Nation’s data was used.
The women’s baseline median age was nearly 50 years and were tracked from 2000 to 2008.
Annual air pollution exposure linked to residential addresses was then analysed with researchers examining a possible link between pollution exposure and body size.
They made the startling discovery that air pollution did in fact impact body fat causing a higher proportion of fat and a lower lean mass among midlife women.
“Women in their late 40s and early 50s exposed long-term to air pollution—specifically, higher levels of fine particles, nitrogen dioxide and ozone—saw increases in their body size and composition measures,” said Xin Wang, epidemiology research investigator at the U-M School of Public Health and the study's first author.
As the study focused on middle aged women, the findings can't be generalised to men or women in other age ranges, Wang further added.
The research also found, however, that while body fat increased by 4.5%, high levels of physical activity were an effective way to mitigate the effects of air pollution exposure.
Obesity among children
The association of air pollution and obesity has also been found among children.
The International Journal of Obesity found potential effects of air pollution on child obesity.
The journal wrote: “Early life exposure to air pollution may be associated with a small increase in the risk of developing overweight and obesity in childhood, and this association may be exacerbated in the most deprived areas.
It added: “Even these small associations are of potential global health importance.”
The International Journal of Obesity also highlighted the potential effects of ambient air pollution on child obesity development but noted evidence is still scarce.
“Early life exposure to air pollution may be associated with a small increase in the risk of developing overweight and obesity in childhood, and this association may be exacerbated in the most deprived areas,” the journal notes. “Even these small associations are of potential global health importance.”
In another study by the Lung Care Foundation and Pulmocare Research and Education, 39.8% of children from Delhi, one of the world’s most polluted cities, were obese or overweight.
This was as opposed to 16.4% of children from Kottayam and Mysuru, cities with much less air pollution.
According to the NHS, the best way to combat obesity is by eating a healthy reduced-calorie diet and exercising regularly.
A calorie-controlled diet should be recommended by a GP or weight loss management health professional.
