In 2013 there were about 31 million deaths globally in 188 countries due to the top risk factors.

In 1990 the biggest risk factors were child and maternal malnutrition, unsafe water, sanitation and handwashing – but these had now been replaced by dietary risks and high systolic blood pressure.

The study was conducted by an worldwide consortium of researchers working on the Global Burden of Disease project and led by the Institute for Health Metrics and Evaluation (IHME) and led by the University of Washington and the University of Melbourne.

A poor diet – which involves eating too few vegetables, fruits, nuts and grains and too much red meat, salt and sugar – was shown to be a bigger killer than smoking and alcohol.

According to the study, unhealthy eating serves as the culprit for many fatal illnesses such diabetes, heart disease and stroke.

Smoking, alcohol use, high body mass index (BMI), high cholesterol and high fasting plasma glucose (FPG) rounded out that list.

A high BMI was also the leading risk in Spain, France, Switzerland and Belgium. Over the study period, the number of deaths attributable to the condition rose by 59% among men, compared with 39.9% among women. Overall, the leading risk factors were the same as for deaths – high blood pressure, smoking, and obesity.

“It is important to remember that we need to focus on preventing these risk factors such as smoking, obesity, poor diet”.

“Many of the leading causes of death in the United States are preventable”, said Dr. Ali Mokdad, Professor of Global Health at IHME and an author of the study, in a news release. The latest study, published in the Lancet medical journal, is the first update, taking in data from 108 countries, and expands the number of risk factors for premature death around the world from 67 to 79.

Authors: C. J. Murray, A. D. Lopez et al. Its combination of childhood undernutrition, unsafe water, unsafe sex and alcohol use is unseen to the same degree elsewhere. Many of these risk factors are related to lifestyle choices, and treatments are often available.

“Progress against so many leading risk factors is excellent news and should be celebrated, but these risks still continue to contribute to the disabilities and deaths of thousands of Britons”, said Dr Ivy Shiue, senior researcher at Northumbria University and a coauthor of the study.

However, high blood pressure was found to be a greater burden for men than women.

But sub-Saharan Africa has a different pattern of risks from the rest of the world.

The addition of wasting, which was associated with about one out of every five deaths in children under 5 in 2013, and stunting, which contributed to 3.5% of under-5 deaths, highlights the importance of child undernutrition as a risk factor.

Unsafe sex took a huge toll on global health, contributing to 82 per cent of HIV/AIDS deaths and 94 per cent of HIV/AIDS deaths among 15- to 19-year-olds in 2013. Deaths from this cause were especially common in the African countries of Chad, South Sudan, Democratic Republic of Congo, Somalia and Niger. The global burden of unsafe sex grew from 1990 and peaked in 2005.