Going vegetarian will likely extend your lifespan, a new study has shown -- but only if you stick at it for at least 17 years.
Physicians at the Mayo Clinic in the US looked at six previous studies on how different diets affected mortality, and found the data proves beyond doubt that eating meat increases your chances of dying young.
Going vegetarian for at least 17 years was linked to a lifespan boost of 3.6 years.
"This data reinforces what we have known for so long -- your diet has great potential to harm or heal," says Prof Brookshield Laurent of the New York Institute of Technology College of Osteopathic Medicine.
"This clinical-based evidence can assist physicians in counselling patients about the important role diet plays, leading to improved preventive care, a key consideration in the osteopathic philosophy of medicine."
Eating significant amounts of processed meat such as salami, bacon and hot dogs was linked to even higher rates of mortality.
"A vegan diet has been shown to improve several parameters of health, including reversal of cardiovascular disease, decreased BMI, decreased risk of diabetes, and decreased blood pressure," reads the study, published in the Journal of the American Osteopathic Association.
"Avoidance of red and processed meats and a diet rich in plant-based whole foods including fruits, vegetables, whole grains, nuts, and legumes is a sound, evidence-based recommendation."
If patients find it too hard to give up meat -- an easy source of protein -- they should at least consider switching to fish or poultry, the study's authors conclude.