‘However, our data suggests that animal-based low carbohydrate diets, which are prevalent in North America and Europe, might be associated with shorter overall life span and should be discouraged.’

Of those taking part in the study, 6,283 died before it was completed.

When their deaths were studied, it was found that those who consumed a lower amount of carbs in their diet were 20 per cent more likely to die than those who ate carbohydrates more moderately.

While those with a medium consumption might expect to live for another 33 years from the age of 50 to 83; those who ate less carbs could expect to live to 79. The group that consumed the most carbs came out with a life expectancy of 82. 

Professor Walter Willett of Harvard School of Public Health, who co-authored the study, said: ‘These findings bring together several strands that have been controversial.

‘Too much and too little carbohydrate can be harmful but what counts most is the type of fat, protein, and carbohydrate.’

Researcher Professor Scott Solomon of Harvard Medical School, added: ‘This work provides the most comprehensive study of carbohydrate intake that has been done to date, and helps us better understand the relationship between the specific components of diet and long term health.

‘These data suggest that shifting towards a more plant-based consumption is likely to help attenuate major morbid disease.’

Read the full paper in the Lancet here