Being overweight or obese¹ is a growing cause of cancer in the UK while cases caused by smoking are falling, according to a large study.

据一项大型研究显示，超重或肥胖是英国癌症日益增长的原因，而吸烟导致的病例则正在下降。

Cancer Research UK found more than a third of all cases of cancer were avoidable - some 135,000.

英国癌症研究所发现，超过三分之一的癌症病例是可以避免的--即大约13.5万例。

The charity also found that excess weight now caused 6.3% of all cancer cases - up from 5.5% in 2011 - while smoking as a cause had declined.

该慈善机构还发现，超重现在占所有癌症病例的成因的6.3%--从2011年的5.5%有所上升，而吸烟作为成因已经下降。

Cancer Research UK found the country with the greatest proportion of preventable causes of cancer was Scotland with 41.5%, followed by Northern Ireland on 38%, Wales on 37.8%, and England on 37.3%.

英国癌症研究所发现，可预防癌症成因的比例最高的国家是苏格兰，占41.5%，其次是北爱尔兰38%，威尔士37.8%，英格兰37.3%。

Across the UK, smoking remained by far the leading cause of preventable cancer, although it dropped from 19.4% in 2011 to 15.1%.

在整个英国，吸烟仍然是导致可预防癌症的主要原因，但从2011年的19.4%降至15.1%。

Second was being overweight or obese, and third was exposure to UV radiation from the sun and sunbeds.

其次是超重或肥胖，第三是暴露于太阳和日光浴床的紫外线辐射。

The standard way of diagnosing if someone is obese is by calculating their body mass index (BMI). It measures whether you're a healthy weight for your height.

诊断是否肥胖的标准方法是计算其体重指数（BMI）。它可以衡量你是否有一个健康的身高体重比。

A BMI of more than 25 means you're overweight and a BMI of more than 30 means you're classified as obese, although there are some exceptions.

BMI超过25就意味着你超重，BMI超过30则意味着你被归类为肥胖，尽管这其中存在一些例外。