Malnutrition in the world: projection of eating behaviors until 2100 and impacts on food security, public health and the environment

Jan 08, 2021
Sébastien Bouley

The nutrition transition is transforming food systems globally and shaping public health and environmental change. A recent German study provides a comprehensive prospective assessment of an ongoing nutritional transition and its interrelated symptoms with respect to food consumption. These symptoms range from insufficient and unbalanced nutrition to obesity, food waste and environmental pressure. Diets are changing around the world, but not synchronously, from rare plant-based diets with fresh, unprocessed foods to diets high in sugar, fat, and animal foods, containing food products, highly processed.

  • Undernutrition decreases in relative terms but stagnates in absolute numbers

Projections from the study highlight that current efforts to tackle undernutrition will fail to meet the Sustainable Development Goal of ending hunger (SDG2) by 2030 as underweight remains a persistent problem, affecting several hundred million people. The prevalence of underweight in an intermediate scenario only decreases from 744 million in 2010 (11%) to 528 million (6%) and to 394 million (4%) by 2100.

  • The obesity epidemic is progressing

As undernutrition is just starting to decline in middle-income countries, overweight and obesity are starting to spread. In our intermediate scenario, overweight and obesity go from 1993 million (29%) in 2010 to 4135 million (45%) in 2050 and 5018 million (56%) in 2100. Similarly, the number of obese people increases from 636 million (9%) in 2010 to 1493 million (16%) in 2050 and 2052 million (23%) in 2100. While only 1% of children were obese in 1965, obesity reached 6% in 2010 and could still increase to 9% in 2050 and 13% in 2100, again violating SDG2 targets to end all forms of malnutrition. In children, overweight and obesity are higher in males than in females. In adults, being overweight is more common in working-age men, but obesity is similar in men and women and is higher in women aged 60 and over. In the absence of behavior change, the results of the study swho a future characterized by overweight and obesity of pandemic magnitude. This future path opposes the SDG2 target of ending all forms of malnutrition and places a heavy burden on public health. In the United States alone, the costs of diagnosed diabetes are estimated at US $ 327 billion in 2017.

  • The relentless growth of food demand

They estimated that global food demand, which increased from 12 exajoules (1018 J, EJ) in 1965 to 30 EJ in 2010, will increase further and could reach 45 (43–47) EJ in 2050 and 48 (36–62) EJ in 2100. During the period 1965-2010, the greatest increase in world food demand came from Asia and North Africa, while in the future India in particular and Africa will be the drivers of the increase. Increasing the levels of physical activity of the part of the population with a sedentary lifestyle to moderate activity, in line with WHO recommendations, would increase food demand by 5-6% for 2010-2050. A healthier diet could prevent 11 to 12 million premature deaths in adults each year. Global food demand is shaped by this nutritional transition, but also by population growth, changing demographic structure, declining levels of physical activity and increasing household food waste. This growing demand for food is the main driver of agricultural production and therefore also the main interface between human society and the environment. Agriculture covers a third of the world’s land area and is responsible for 70% of human use of blue water. The food system is responsible for 21 to 37% of anthropogenic greenhouse gas emissions. Agriculture has also increased pollutant releases of nutrients to the environment, being the main driver of the five-fold excess nitrogen on land systems compared to pre-industrial times. Finally, agriculture contributes significantly to air and water pollution, soil degradation, resistance to antibiotics, new pathogens, as well as the loss of biodiversity.

Undernutrition, overnutrition and food-related environmental pollution coexist in all regions of the world. The Lancet Commission on the “Global Syndemic of Obesity, Undernourishment and Climate Change” stresses that this synergy of three epidemics represents the main health challenge of the 21st century, and urges the scientific community to develop modeling studies to provide evidence.

To learn more, you can consult the study report.

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