Food production and consumption must change drastically to avoid millions of deaths and "catastrophic" damage to the planet, according to a study published Wednesday in the scientific journal The Lancet.

The key to both goals is a significant shift in the global diet and would mean eating about half as much sugar and red meat and twice as many vegetables, legumes, fruits and nuts, the study found.

Read more: How much meat is healthy?

Researchers from the EAT-Lancet Commission said that if people followed the "Planetary Health" diet, more than 11 million premature deaths could be prevented each year, greenhouse gas emissions would be cut and more land, water and biodiversity would be preserved.

The diet would see adults limited to 14 grams of red meat a day (about 30 calories — a quarter-pound burger patty contains roughly 450 calories), no more than 29 grams of poultry (around one and a half chicken nuggets) and 13 grams of eggs, or just 1.5 eggs per week.

The diet is the result of a three-year project commissioned by The Lancet and involving 37 specialists from 16 countries.

Food system 'overhaul' needed

"We are in a catastrophic situation," said co-author Tim Lang, a professor at the University of London and policy lead for the EAT-Lancet Commission that compiled the study.

Lang said feeding a growing population of 10 billion people by 2050 with a healthy, sustainable diet will be impossible without transforming eating habits, improving food production and reducing food waste.

"We need a significant overhaul, changing the global food system on a scale not seen before," Lang said.

Read more: Berlin: Vegan capital of the world?

"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," Lang added.

Life-threatening diseases including obesity, diabetes, malnutrition and several types of cancer are linked to poor diets.

Researchers said unhealthy diets currently cause more death and disease worldwide than unsafe sex, alcohol, drug and tobacco use combined.

The dietary changes would be felt more in some regions than others. For example, people in North America eat almost 6.5 times the recommended amount of red meat, while people in South Asia eat only half the amount suggested by the planetary diet.

Meanwhile, meeting the targets for starchy vegetables such as potatoes and cassava would require big changes in sub-Saharan Africa, where people on average eat 7.5 times the suggested amount.

"More than 800 million people have insufficient food, while many more consume an unhealthy diet that contributes to premature death and disease," said Walter Willett of Harvard University. "If we can't quite make it, it's better to try and get as close as we can."

law/sms (AFP, Reuters)