Swapping a sausage for whole grain toast, a few tomatoes or a handful of nuts could lead to a much longer life, research has shown.

It might seem like a simple substitution, but exchanging just a small amount of processed red meat for plant protein reduces the risk of early death by 34 per cent. Ditching bacon and eggs could also extend life, the study suggests.

Researchers at Harvard Medical School and Massachusetts General Hospital followed more than 130,000 people for 36 years, monitoring their diet, lifestyle, illness and mortality.

For a man, they found that switching 19g of animal protein – the equivalent of a sausage or a few slices of bacon – for nuts, vegetables, or wholegrains significantly cut the risk of early death. A woman needs to exchange just 15g for the same effect.

Substituting eggs for plant protein also led to a 19 per cent reduction in death risk.