Reducing meat consumption to a quarter of a sausage a day and eating more vegetables and nuts would protect the well-being of future generations and the planet, researchers have said.
The average supermarket sausage weighs around 66g, so around one bite would use up the daily recommended allowance for meat (14g).
Alternatively, Brits could opt for around half a rasher of bacon or a meatball.
Adopting more sustainable eating habits could prevent 11 million premature deaths per year by 2050, scientists have claimed in a new report published by the EAT-Lancet Commission.
It says red meat and sugar consumption would have to be slashed by at least half, while that of nuts, fruits, vegetables and legumes such as lentils and chickpeas must double.
The diet would also reduce the damaging effects of soil erosion, deforestation and loss of biodiversity.
Researchers say current diets, with a growing emphasis on Western-style high calorie foods laden with saturated fats, are pushing the planet beyond its natural boundaries while causing ill-health and early death.
The diet consists of 35 per cent of calories coming from whole grains, 500 grams of vegetables and fruits, protein mostly derived from plants, and just 14 grams of red meat per day.
Poultry consumption would be confined to 29 grams - equivalent to one and a half nuggets - and fish to 28 grams, a quarter of a medium sized fillet.
Eggs would be restricted to around 1.5 per week and dairy to 250g per day, the equivalent of one glass of milk.
How to eat to save the planet
Nuts - 50g a day
Beans, chickpeas, lentils and other legumes - 75g a day
Fish - 28g a day
Eggs - 13g a day (one and a bit a week)
Meat - 14g a day of red meat and 29g a day of chicken
Carbs - whole grains such as bread and rice 232g a day and 50g a day of starchy vegetables
Dairy - 250g - one glass of milk
Vegetables - (300g) and fruit (200g)
Professor Tim Lang, one of the authors from City, University of London, said: "The food we eat and how we produce it determines the health of people and the planet, and we are currently getting this seriously wrong.
"We need a significant overhaul, changing the global food system on a scale not seen before in ways appropriate to each country's circumstances.
"While this is unchartered policy territory and these problems are not easily fixed, this goal is within reach and there are opportunities to adapt international, local and business policies.
"The scientific targets we have devised for a healthy, sustainable diet are an important foundation which will underpin and drive this change."
Findings from the experts are reported in the latest issue of The Lancet medical journal.
Widespread adoption of the planetary health diet would improve intakes of healthy nutrients, such as non-saturated fats, minerals and vitamins, while reducing consumption of potentially harmful foods, they said.
Three computer models simulating the effects of the diet predicted that between 10.9 and 11.6 premature deaths could be averted per year. Adult death rates would be reduced by up to 23.6 per cent.
The study authors recommended policies improving the availability of healthy food from sustainable sources, restricting advertising of unhealthy food, and promoting education campaigns.
Healthy food would also have to be affordable, and "social protection" for low-income groups may be needed to ensure they do not miss out, they said.
Levels of food waste would also have to be halved at least, said the experts.
Professor Johan Rockstrom, from the Potsdam Institute for Climate Impact Research in Germany - who co-led the Commission, said a sustainable system that could deliver healthy diets for a growing and wealthier world population required "nothing less than a new global agricultural revolution".
Christopher Snowdon, head of lifestyle economics at the IEA, accused the authors of the planetary health diet of campaigning for a "nanny state".
He added: "Their desire to limit people to eating one tenth of a sausage a day leaves us in no doubt that we are dealing with fanatics.
"They say they want to save the planet but it is not clear which planet are they on."