The demand for food grows as people grow up. Feeding a population of 9,000 million by 2050 will require much more food than the one calculated above.
"It will be harder to feed 9 billion people by 2050 than it would be today," says Gibran Vita, a doctorate. candidate for the Industrial Ecology Program of the Norwegian University of Science and Technology.
According to WWF, the greatest environmental problem in the world is the destruction of wildlife and plant habitat. A large part of the devastation is due to the demands of a growing human population. On the other hand, Zero Hunger is the second Objective of Sustainable Development of EE. U., And its challenge is to meet a growing global food demand.
The world's population could level around 9,000 million in a few years, compared to just over 7,600 million now.
But an average person in the future will demand more food than today. Changes in eating habits, attitudes toward food waste, height and body mass increases, and demographic transitions are some of the reasons.
People are changing
Professor Daniel B. Müller and his colleagues, Felipe Vásquez and Vita, analyzed the changes in the populations of 186 countries between 1975 and 2014. "We studied the effects of two phenomena. One of them is that people in average have become taller and more Heavy. The average population is getting older, "said Vita.
The first phenomenon contributes to the increased demand for food. The second counteracts the first one.
An average adult in 2014 was 14 percent heavier, 1.3 percent higher, 6.2 percent older and 6.1 percent more than in 1975. Researchers expect this trend to continue in most of the countries
"A global average adult consumed 2465 kilocalories per day in 1975. In 2014, the average adult consumed 2615 kilocalories," says Vita.
Globally, human consumption increased 129 percent during this time period. The growth of the population was responsible for 116 percent, while the increase in weight and height accounted for 15 percent. Older people need a little less food, but the aging population results in only two percent less consumption.
"The 13 percent additional corresponds to the needs of 286 million people," says Vásquez.
This in turn corresponds to the combined needs of Indonesia and Scandinavia.
There are considerable variations between countries. The weight increase per person between 1975 and 2014 varied between 6 and 33 percent, and the increase in energy demand ranged between 0.9 percent and 16 percent.
An average Tonga person weighs 93 pounds. A Vietnamese medium weighs 52 kilos. This means that the inhabitants of Tonga need 800 kilocalories each day or about four oat cups.
Some countries are changing rapidly. In Santa Lucía in the Caribbean, the average weight went from 62 kilos in 1975 to 82 kilos 40 years later.
The lowest and highest changes are found in Asia and Africa, reflecting the disparities between the countries of these continents.
It was not calculated above
"Previous studies did not take into account the growing demands of older individuals and societies to estimate the future food needs of a growing population," Vásquez said.
Most studies estimate that the nutritional needs of an average adult remain constant over time and are quite similar among nations. But that is not the case.
"These assumptions can cause errors in the evaluation of how many foods we really need to meet future demand," says Vásquez.
This study provides relevant information for the Food and Agriculture Organization of the United Nations (FAO), which is the leader in the struggle to ensure food security for all.
Vásquez and Vita say that we have to look more than the number of people in an area to understand the mechanisms behind their consumption. This requires a multidisciplinary approach that considers both social and physiological factors.
The analysis of this study involved biodemography, a hybrid of biology and demography. The researchers have adapted a model for dynamic systems that are often used in industrial ecology to study resources and resource flows.
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Felipe Vásquez et al., Food security for an aging population and heavier, Sustainability (2018). DOI: 10.3390 / su10103683