The world is not growing enough fruit and vegetables for everyone to eat healthily, according to a new study.

A global appetite for fat and sugar, alongside a surge in grain production to feed developing countries, has led to a system that cannot provide balanced diets for all.

In order to feed the world’s rapidly expanding population with healthy diets, the scientists said more fruit and vegetables must be produced alongside a shift to plant-based proteins.

They found that such a shift would also reduce land use and cut greenhouse gas emissions, meaning it would be good for the planet as well as the global population.

“We simply can’t all adopt a healthy diet under the current global agriculture system,” said Professor Evan Fraser of the University of Guelph, one of the study’s co-authors.

The scientists based their research on Harvard University’s “healthy eating plate” guide, which recommends half of our diets consist of fruit and vegetables, a quarter whole grains and the remaining quarter protein, fat and dairy.

10 photographs to show to anyone who doesn't believe in climate change Show all 10 1 /10 10 photographs to show to anyone who doesn't believe in climate change 10 photographs to show to anyone who doesn't believe in climate change A group of emperor penguins face a crack in the sea ice, near McMurdo Station, Antarctica Kira Morris 10 photographs to show to anyone who doesn't believe in climate change Floods destroyed eight bridges and ruined crops such as wheat, maize and peas in the Karimabad valley in northern Pakistan, a mountainous region with many glaciers. In many parts of the world, glaciers have been in retreat, creating dangerously large lakes that can cause devastating flooding when the banks break. Climate change can also increase rainfall in some areas, while bringing drought to others. Hira Ali 10 photographs to show to anyone who doesn't believe in climate change Smoke – filled with the carbon that is driving climate change – drifts across a field in Colombia. Sandra Rondon 10 photographs to show to anyone who doesn't believe in climate change Amid a flood in Islampur, Jamalpur, Bangladesh, a woman on a raft searches for somewhere dry to take shelter. Bangladesh is one of the most vulnerable places in the world to sea level rise, which is expected to make tens of millions of people homeless by 2050. Probal Rashid 10 photographs to show to anyone who doesn't believe in climate change Sindh province in Pakistan has experienced a grim mix of two consequences of climate change. “Because of climate change either we have floods or not enough water to irrigate our crop and feed our animals,” says the photographer. “Picture clearly indicates that the extreme drought makes wide cracks in clay. Crops are very difficult to grow.” Rizwan Dharejo 10 photographs to show to anyone who doesn't believe in climate change Hanna Petursdottir examines a cave inside the Svinafellsjokull glacier in Iceland, which she said had been growing rapidly. Since 2000, the size of glaciers on Iceland has reduced by 12 per cent. Tom Schifanella 10 photographs to show to anyone who doesn't believe in climate change A river once flowed along the depression in the dry earth of this part of Bangladesh, but it has disappeared amid rising temperatures. Abrar Hossain 10 photographs to show to anyone who doesn't believe in climate change A shepherd moves his herd as he looks for green pasture near the village of Sirohi in Rajasthan, northern India. The region has been badly affected by heatwaves and drought, making local people nervous about further predicted increases in temperature. Riddhima Singh Bhati 10 photographs to show to anyone who doesn't believe in climate change A factory in China is shrouded by a haze of air pollution. The World Health Organisation has warned such pollution, much of which is from the fossil fuels that cause climate change, is a “public health emergency”. Leung Ka Wa 10 photographs to show to anyone who doesn't believe in climate change Water levels in reservoirs, like this one in Gers, France, have been getting perilously low in areas across the world affected by drought, forcing authorities to introduce water restrictions. Mahtuf Ikhsan

They then worked out how much land is currently used for farming, as well as how it is currently divided, and how much would be needed if everyone stuck to the Harvard system.

The results revealed a rift between the ideal and the reality, with 12 servings of grain being produced per person, instead of eight, and just five servings of fruit and vegetables instead of the recommended 15.

Levels of fat and sugar production were also far higher than is necessary for a healthy population.

In order to achieve self-sufficiency, developing countries have pumped masses of investment into grain and corn production in recent decades, and the researchers said some of this capacity must be swapped for other crops.

There was also a smaller shortfall in the amount of protein being produced, with three servings per person instead of five.

To bring protein consumption up to the required amount, the scientists recommended that a greater emphasis must be placed on plant-based proteins instead of animals.

“Major players in the protein industry are investing in alternative protein options such as plant-based proteins, and consumers are taking advantage of the recent increase in alternative protein options hitting the market,” said Professor Fraser.

Support free-thinking journalism and attend Independent events

Meat production uses huge amounts of land and resources, and is a major contributor to greenhouse gas emissions.

Unless the appropriate changes are made, feeding the 9.8 billion people expected to make up the global population by 2050 will require 12 million more hectares of arable land and at least one billion more hectares of pasture land.