A study has said that we aren't producing enough fruit and vegetables for everyone to eat a healthy diet.

Published in the journal PLOS One, the research led by the University of Guelph looked at global agricultural production, extrapolating to the year 2050, compared with how much food nutritionists say we should eat. And the results weren’t particularly good news.

"We simply can't all adopt a healthy diet under the current global agriculture system," Professor Evan Fraser from the University of Guelph, a co-author on the study, said in a statement.

Professor Fraser added that while we are currently overproducing grains, fats, and sugars, production of fruits and vegetables are “not sufficient to meet the nutritional needs of the current population.”

To make their findings, the team worked on the assumption that half of our diet should consist of fruit and vegetables, a quarter whole grains, and the other quarter consisting of protein, fat, and dairy. These are recommendations in Harvard University’s “Healthy Eating Plate” guide.

Then they looked at how much land was being used for farming, and how much we’d need to meet these guidelines, projecting the findings to 2050 when the global population could reach 9.8 billion, according to the United Nations. And while there were plenty of grains, sugar, and fat to go round, fruits and vegetables, and proteins too, were in short supply.

“They found that we now produce 12 servings of grains per person instead of the recommended eight; five servings of fruits and vegetables instead of 15; three servings of oil and fat instead of one; three servings of protein instead of five; and four servings of sugar instead of none,” the statement noted.

One reason for this might be that developing countries tend to focus on carbohydrates, which are easier to produce. These countries have also spent more money researching and developing such crops, rather than fruits or vegetables.

The other issue is that fat, sugar, and salt “are tasty”, noted co-author Krishna KC. "All of these factors combined have resulted in a world system that is really overproducing these types of foods."

To meet the recommendations, the researchers said we would need to eat less meat, while more plant-based proteins would need to be developed. And if we don’t change, by 2050 we could need 12 million more hectares of arable land and 1 billion hectares of pasture land to meet current demand.