At least 33,000 lives could be saved each year if the nation ate more healthily, claim researchers.
Eating five portions of fruit and vegetables a day would by itself prevent 15,000 early deaths, including 7,000 from coronary heart disease, almost 5,000 from cancer and more than 3,000 from stroke.
Increasing dietary fibre would save another 4,000 lives, the study from Oxford University suggests, while watching fat intake would save almost 7,000, and another 7,500 early deaths would be prevented by reducing salt consumption.
The study, published in the Journal of Epidemiology and Community Health, analysed deaths from coronary heart disease, stroke and cancers, figures on food and nutrient intake, and studies on the influence of diet on illness and early death for 2005 to 2007.
The UK’s nutritional goals and guidelines are for people to eat 440g of fruit and vegetables every day and 18g of fibre.
A third of the total number of calories should come from fat but saturated fat should make up only ten per cent. People should also consume no more than 6g of salt a day.
However, the researchers found no country in the UK fully meets the criteria, with Scotland and Northern Ireland doing the worst.
In fact, figures earlier this year showed that Britons were actually becoming less likely to eat the recommended amount of fruit and vegetables. Only about a third of Britons are thought to hit the five-a-day target.
Oxford’s Dr Peter Scarborough, who led the latest research, said: ‘Meeting dietary recommendations would have a massive effect on the health of the nation.
‘According to our model, the biggest impact would be eating more fruit and veg.’
Victoria Taylor, senior dietician of the British Heart Foundation, which co-funded the study, said: ‘By eating more fruit and vegetables there is less room in your diet for other foods that might not be great for your heart.’