An increase in the amount of beef, lamb and sausages in your diet can shorten your life, says a new study.

Scientists have linked red and processed meat to a range of diseases, and the World Health Organization has categorized it as a cause of cancer. However, it is difficult to determine if they can be associated with premature deaths.

Research published in the British Medical Journal suggests that there is an association between changing dietary habits – much more red meat and processed meats such as bacon and ham – and an increased risk of premature dying. Reducing and eating more fish, chicken, vegetables and nuts seems to reduce the risk.

The study was conducted by a research team in the US and China that examined the eating habits of approximately 54,000 women and 28,000 men over a period of eight years and the mortality rates over the next eight years. Everyone involved was a health professional in the United States in the 1980s and '90s.

Every four years, they were asked to complete a questionnaire asking them how often they ate different types of food, from "never or less than once a month" to "six or more times a day". There were more than 14,000 deaths during the investigation period, which ended in 2010. The main causes were cardiovascular diseases, cancer, respiratory diseases and neurodegenerative diseases.

The researchers found that increasing total intake of red and processed meat by 3.5 servings per week or more over a period of eight years was associated with a 10% greater risk of death over the next eight years.

Consuming more processed meat resulted in a higher risk of early death than eating unprocessed red meat – 13% vs. 9%.

By cutting one serving of red meat per day and eating fish instead, the risk of death decreased by 17% over the next eight years.

The authors admit that they can not prove that red and processed meat were the cause of death because it is an observational study. Although they took into account factors such as physical activity, the overall quality of the diet, smoking, and alcohol intake, there may be other things that cause the heavy meat eaters to die earlier.

But they write: "Changing the source of protein or eating healthy plant foods like vegetables or whole grains can improve longevity."

"We do not say that anyone should become vegetarian or vegan," said lead author Frank B Hu of the Harvard TH Chan School of Public Health in Boston. "However, replacing some of the red meat with plant foods is a great benefit."

Exactly what you eat instead of meat is important, he said. "It's not a good idea to eat less ultra-processed foods and sugar."

Policies and strategies are needed to make healthier food more affordable. "If the healthier alternatives are inaccessible and too expensive, it's very difficult for people to change their eating habits," he said.

"The impact on public health could be quite large, since the consumption of red and processed meat is quite high, especially in the western population."

Some scientists were careful. Kevin McConway, emeritus professor of applied statistics at the Open University, said it was "an important new study that added something useful to what was previously known", but the size of the associations was "not huge."

On average, people were around 60 years old when the mortality rate was recorded. In the UK, about five out of every 100 women die in the eight years after they are 60 and eight out of 100 men.

It's impossible to be sure that the increased risk of death is caused by meat consumption, McConway said. If that were the case and everyone ate seven slices of bacon a week between the ages of 52 and 60, "About one in 100 women would die, and less than that – anywhere between 0 and 1 – more men would die. In total, between one and two additional deaths of 200 men and women. That's an increase, but not an enormous one, and additional seven slices of bacon a week are a significant change. "

Nutrition experts said the studies affirmed the warning that too much red and processed meat is not healthy. A recent study of more than 400,000 people across Europe found that eating red and processed meat is associated with a 19% increased risk of ischemic heart disease, which is a major cause of premature mortality, said Tom Sanders, emeritus Professor of nutrition and dietetics at King's College London.

"These findings, taken together, challenge the popular myth that high-protein, high-fat diets are good for your health, but support the current dietary guidelines that advocate a shift to a Mediterranean diet that includes plenty of vegetables, nuts, whole grains, some of them Fish, poultry and milk, but only very small amounts of red and processed meat, "he said.