Feeding the future population

With the population increasing, demographics shifting and attitudes to food changing, will the world be able to keep up with the future demand for food?

The world's population could level off at around 9 billion in a few years, compared to just over 7.6 billion now. Researchers from the Norwegian University of Science and Technology (NTNU) stated that feeding the future population will be challenging, as the average person will require more food due to changes in eating habits and increases in height and weight.

Professor Daniel B Müller and colleagues Felipe Vásquez and Gibran Vita analysed changes in the populations of 186 countries between 1975 and 2014.

"We studied the effects of two phenomena. One is that people on average have become taller and heavier. The second is that the average population is getting older," said Vita, PhD candidate at NTNU's Industrial Ecology Programme.

Compared to 1975, an average adult in 2014 was about 14% heavier, 1.3% taller and 6.2% older, and needed 6.1% more energy. Vita continued: "An average global adult consumed 2465 kilocalories per day in 1975. In 2014, the average adult consumed 2615 kilocalories."

Graphic: NTNU.

Globally, human consumption increased by 129% during this time span; 116% due to population growth and 15% due to increased weight and height. Although older people need less food, an ageing population only resulted in a 2% reduction in consumption.

"The additional 13% corresponds to the needs of 286 million people," Vásquez said, which is the approximate food needs of Indonesia and Scandinavia combined.

The researchers found considerable variations between countries. Weight gain per person from 1975 to 2014 ranged from 6 to 33%, and the increased energy requirement ranged from 0.9 to 1%.

An average person from Tonga weighs 93 kg, compared to the 52 kg of the average Vietnamese person, meaning Tongan people need 800 more kilocalories each day.

While some countries like Saint Lucia in the Caribbean are changing quickly, with weight increasing from 62 kg in 1975 to 82 kg 40 years later, the lowest and highest changes are found in Asia and Africa. The researchers said this reflects the disparities between the countries of these continents.

Most studies estimate that an average adult's food needs remain constant over time and fairly similar across nations, but Vásquez said this is not the case.

"Previous studies haven't taken the increased demands of larger individuals and aged societies into account when calculating the future food needs of a growing population," he said. "These assumptions can lead to errors in assessing how much food we'll actually need to meet future demand."

The results may be used to help the UN's Food and Agriculture Organization (FAO) in their attempt to ensure global food security.

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