The food we eat is putting 11 million of us into an early grave each year, an influential study shows.
The analysis, in the Lancet, found that our daily diet is a bigger killer than smoking and is now involved in one in five deaths around the world.
Salt – whether in bread, soy sauce or processed meals – shortened the highest number of lives.
Researchers say this study is not about obesity, but “poor quality” diets damaging hearts and causing cancer.
The Global Burden of Disease Study is the most authoritative assessment of how people are dying in every country in the world.
The latest analysis used estimates of countries’ eating habits to pin down how often diet was shortening lives.
The dangerous diets were those containing:
Too much salt – three million deaths
Too few whole grains – three million deaths
Too little fruit – two million deaths
Low levels of nuts, seeds, vegetables, omega-3 from seafood and fibre were the other major killers.
“We find that diet is one of the dominant drivers of health around the world, it’s really quite profound,” Prof Christopher Murray, the director of the Institute for Health Metrics and Evaluation at the University of Washington said.
About 10 million out of the 11 million diet-related deaths were because of cardiovascular disease and that explains why salt is such a problem.
Too much salt raises blood pressure and that in turn raises the risk of heart attacks and strokes.
Salt can also have a direct effect on the heart and blood vessels, leading to heart failure when the organ does not work effectively.
Whole grains, fruit and vegetables have the opposite effect – they are “cardioprotective” and lower the risk of heart problems.
Cancers and type 2 diabetes made up the rest of the diet-related deaths.
No country is perfect and each favours some part of a healthy diet more than others, but this is how far the world is from an optimal diet.
The healthy foods missing from the most diets around the world were nuts and seeds, according to the study.
Eager readers will have noticed they featured heavily in the planetary health diet, unveiled in January, to save lives, save the planet and feed 10 billion people.
So why don’t we munch them?
Prof Nita Forouhi, from the University of Cambridge, said: “The perception is they are little packs of energy that will make you fat, whereas they are packed full of good fats.
“And most people don’t see them as mainstream food; and the other issue is cost.”
The huge fat versus sugar debate and the link between red and processed meats with cancer have attracted huge headlines in recent years.
“These can be harmful as we show, but they are much smaller issues than low whole grains, fruit, nuts, seeds and vegetable intake,” said Prof Murray.
Although, the study did show too many fizzy drinks were being drunk in every corner of the world.
The researchers say it is time for health campaigns to switch from talking about nutrients like fat and sugar and instead promote healthy foods.
Bad diets are knocking a couple of years off life expectancies around the world, according to the researchers.
But Prof Murray warns this is just the average and says the real question we should be asking is: “Am I going to die in my 50s from a heart attack? Or am I going to have some of the diet-related cancers in my 40s?”
Mediterranean countries, particularly France, Spain and Israel, have some of the lowest numbers of diet-related deaths in the world.
Countries in South East, Southern and Central Asia are at the opposite end of the spectrum.
Israel has the lowest diet-related deaths – 89 per 100,000 people a year
Uzbekistan has the highest diet-related deaths – 892 per 100,000 people a year
Japan and China have curiously contrasting fortunes that reflect their changing relationship with salt.
China consumes enormous amounts of salt with soy and other salty sauces being a key part of the country’s cuisine.
But the rising popularity of processed foods is introducing yet more salt to their diet. It has the highest death rate because of salt of any country.
Prof Murray said: “Japan is very interesting because if you go back 30 to 40 years, they like China today had enormous salt intake.
“Salt is still their number one problem, but it has come down dramatically,
“And they have a diet that is higher in many of the things we think are protective for heart disease such as vegetables and fruit.”
Prof Murray said: “Diet quality matters no matter what weight you are.
“The really big story for people to act on is increase your whole grains, fruit, nuts, seeds and vegetable intake and reduce salt if you can.”
But money is an issue.
It is estimated that having your five fruit and veg a day would take up 52% of household income in poorer countries.
But Prof Forouhi warns: “The public can make healthier choices if informed and have the resources, but if what is on the shelves as buy-one-get-one-free is always unhealthy, then that message will fall down.
“Cheaper options that are healthy are badly needed.”
Both agreed there needed to be a shift from focusing on nutrients (fat/sugar/salt) and on to which actual foods people should eat.