Eleven million deaths worldwide in 2017 were linked to people eating poor diets high in sugar, salt and processed meat that contributed to heart disease, cancer and diabetes, a global study found.
The research, published in the Lancet medical journal, found that among 195 countries studied, the proportion of diet-related deaths was highest in Uzbekistan and lowest in Israel.
Ireland ranked 24th, just ahead of Britain at 23rd, the US was 43rd, while India was 118th and China was at 140th.
Consumption of healthier foods such as nuts and seeds, milk and whole grains was on average too low, and people consumed too many sugary drinks and too much processed meat and salt.
This led to one in five deaths in 2017 being linked to bad diets.
The Global Burden of Disease study tracked trends from 1990 to 2017 of consumption of 15 dietary factors.
Chris Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington which led the work, said it "affirms what many have thought for several years".
"Poor diet is responsible for more deaths than any other risk factor in the world," he said.
"Our assessment suggests the leading dietary risk factors are high intake of sodium, or low intake of healthy foods, such as whole grains, fruit, nuts and seeds and vegetables."
The study found people ate only 12% of the recommended amount of nuts and seeds - an average intake of 3g a day, compared with the recommended 21g - and drank more than 10 times the recommended amount of sugary drinks.
Diets high in sugar, salt and bad fats are known risk factors for heart disease, stroke, diabetes and many types of cancer.
The global diet also included less than a quarter of the recommended amount of whole grains - at 29g average intake a day compared with the recommended 125g - and almost double the recommended amount of processed meat - at around 4g average intake per day compared with the 2g recommended.
A study published in January suggested an "ideal diet" for the health of people and the planet would include a doubling of consumption of nuts, fruits, vegetables and legumes, and a halving of meat and sugar intake.
In a breakdown of diet-related deaths, the study found that of the 11 million in 2017, almost 10 million were from cardiovascular diseases, around 913,000 from cancer, and almost 339,000 from type 2 diabetes.
Annual deaths related to diet have increased from eight million in 1990, but the researchers said this was largely due to increases in populations and populations ageing.
In January, a consortium of three dozen researchers called for a dramatic shift in the way the world eats.
The EAT-Lancet report said that the global population must eat roughly half as much red meat and sugar, and twice as many vegetables, fruits and nuts in order to avert a worldwide obesity epidemic and avoid "catastrophic" climate change.
Authors of today's study noted that economic inequality was a factor in poor dietary choices in many countries.
It found that on average, reaching the "five-a-day" fruit and vegetable servings advocated by doctors cost just 2% of household income in rich nations, but more than a half of household income in poorer ones.
"This study gives us good evidence of what to target to improve diets, and therefore health, at the global and national level," said Oyinlola Oyebode, Associate Professor at Warwick Medical School, who was not involved in the research.
"The lack of fruit, vegetables and whole grains in diets across the world are very important - but the other dietary factor highlighted by this study is the high intake of sodium."
