"It will be harder to feed 9 billion people in 2050 than it would be today," said Gibran Vita, a Ph.D. candidate at the Norwegian University of Science and Technology 's Industrial Ecology Program.

According to WWF, the world's greatest environmental problem is the destruction of wildlife and plant habitat. A large part of the devastation is due to the demands of an ever-growing human population. On the other hand, "Zero Hunger" is the second A Sustainable Development Goal and its challenge is to meet

But the average person in the future will require more food than today. Changes in eating habits, attitudes towards food waste, increases in height and body mass, and demographic transitions are some of the reasons.

People are changing

Professor Daniel B. Müller and colleagues Felipe Vásquez and Vita analyzed changes in the populations of 186 countries between 1975 and 2014. "We studied the effects of two phenomena. The second is that the average population is getting older, "said Vita. The first phenomenon contributes to increased food demand. The second counteracts the former one.

An average adult in 2014 was 14% heavier, about 1.3% workshop, 6.2% older, and needed 6.1% more energy than in 1975. Researchers expect this trend to continue for most countries. "An average global adult consumed 2465 kilocalories per day in 1975. In 2014, the average adult consumed 2615 kilocalories," said Vita.

Globally, human consumption increased by 129% during this time span. Population growth was responsible for 116%, while increased weight and height accounted for 15%. Older people need a little less food, but an aging population results in only 2% less consumption. "The additional 13% corresponds to the needs of 286 million people," Vásquez says. This, in turn, corresponds approximately to the food needs of Indonesia and Scandinavia combined.

Major differences

Considerable variations exist between countries. Weight gain per person from 1975 to 2014 ranged from 6 to 33per cent, and the increased energy requirement ranged from 0.9 to 16%An average person from Tonga weighs 93 kilos. An average Vietnamese weighs 52 kilos. Este means that Tonga people need 800 more kilocalories each day or about four bowls of oatmeal.

Some countries are changing quickly. On Saint Lucia in the Caribbean, the average weight rose from 62 kilos in 1975 to 82 kilos 40 years later. The lowest and highest changes were found in Asia and Africa, reflecting the disparities between the countries of these continents.