Poor diet is a factor in one in five deaths across the world, a study compiling data from every country has found.

A bad diet is the second riskiest lifestyle choice after smoking, and more common, so it tops the list of leading causes of death worldwide.

Other high risk factors are high blood glucose (sugar) which can lead to diabetes, high blood pressure, obesity and high total cholesterol, all of which can be related to eating the wrong foods.

The Global Burden of Disease study, the most comprehensive study ever carried out on the subject, found that millions of people are eating bad diets that are low in whole grains, fruit, nuts and seeds and fish oils and high in salt and sugar.

More than 72% of all 2016 deaths were caused by non-communicable diseases such as cardiovascular or heart disease, cancer, diabetes, lung disease, and Alzheimer’s disease.

The massive new health report also spied a significant impact on mortality from air pollution, as more and more of the world’s population crams into cities.

It also found that people are living longer, with life expectancy in 2016 worldwide at 75 years for women and 70 for men. Japan is the home of the longest life expectancy at 8