Food demand is growing as the number of people increases. Feeding a population of 9 billion by 2050 will require more food than previously calculated.
"It would be more difficult to feed 9 billion people in 2050 than today," said Gibran Vita, Ph.D. candidate in the Norwegian University of Science and Technology Ecology Program.
According to WWF, the biggest environmental problem in the world is the destruction of wildlife and plant habitat. Much of the destruction is due to the growing demands of the human population. On the other hand, Zero Hunger is the second Sustainable Development Goal, and the challenge is to meet the growing global food demand.
The world population can reach around 9 billion in a few years, compared to only 7.6 billion now.
But the average person in the future will need more food than today. Changes in eating habits, attitudes toward leftovers, increased height and body mass, and demographic transitions are a number of reasons.
Professor Daniel B. Müller and colleagues Felipe Vásquez and Vita analyzed changes in a population of 186 countries between 1975 and 2014. "We study the effects of two phenomena. One is that the average person has become taller and heavier. The second is that the average population is getting older, "Vita said.
The first phenomenon contributes to increasing food demand. The second negates the first.
The average adult in 2014 was 14 percent heavier, about 1.3 percent higher, 6.2 percent older, and needed 6.1 percent more energy than in 1975. Researchers expect this trend to continue for most countries.
"The average global adult consumes 2465 kilocalories per day in 1975. In 2014, the average adult consumed 2,615 kilocalories," Vita said.
Globally, human consumption increased by 129 percent during this time period. Population growth was responsible for 116 percent, while an increase in weight and height accounted for 15 percent. Older people need less food, but an aging population only produces two percent less consumption.
"An additional 13 percent fits the needs of 286 million people," Vásquez said.
This in turn corresponds to the food needs of Indonesia and Scandinavia combined.
There are many variations between countries. The increase in body weight per person from 1975 to 2014 ranged from 6 to 33 percent, and energy requirements increased from 0.9 to 16 percent.
The average person from Tonga weighs 93 kilos. The average Vietnamese weighs 52 kilos. This means that Tongan people need 800 kilocalories more every day – or about four bowls of oatmeal.
Some countries change rapidly. In Saint Lucia in the Caribbean, the average weight rose from 62 kilograms in 1975 to 82 kilos 40 years later.
The lowest and highest changes are found in Asia and Africa, which reflect differences between countries from these continents.
Not counted before
"Previous studies have not taken increasing demands from larger individuals and the age community into account when calculating future food needs from a growing population," Vásquez said.
Most studies estimate that the average food needs of adults remain constant over time and are almost the same throughout the country. But it's not like that.
"This assumption can cause errors in assessing how much food we actually need to meet future demand," Vásquez said.
The study provides relevant information for the United Nations Food and Agriculture Organization (FAO), which is a leader in the struggle to ensure food security for all.
Vásquez and Vita say that we must see more than the number of people in a region to understand the mechanism behind their consumption. This requires a multidisciplinary approach that considers social and physiological factors.
Analysis of this study involves bio-demography, hybrid biology and demography. The researchers adapted a model for dynamic systems that are often used in industrial ecology to study the sources and flows of resources.
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Felipe Vásquez et al, Food Security for Aging and Population Heavier, Sustainability (2018). DOI: 10.3390 / su10103683