This paper examines the global nutrition transition and argues that coordinated action is necessary to reduce household food waste, decrease consumption of animal-source foods, limit the prevalence of overweight and eliminate hunger.
Triggered by economic growth, dietary patterns across the world are shifting away from predominantly plant-based, unprocessed foods towards diets high in sugar, fat, animal-source foods and highly-processed foods (see also What is ultra-processed food? And why do people disagree about its utility as a concept?). Undernourishment, meanwhile, remains roughly static when measured in absolute numbers of people affected, partly due to population growth.
The paper predicts that current efforts to tackle undernutrition are unlikely to meet the Sustainable Development Goal 2 of ending hunger by 2030. Instead, a middle-of-the-road scenario sees the prevalence of underweight decline from 11% in 2010 to 6% in 2050 and 4% in 2100. On the other hand, overweight (including obesity) in the same scenario is predicted to rise from 29% in 2010 to 45% in 2050 and 56% in 2100.
Demand for animal-source foods is predicted to rise from 18% of global average calorie intake in 2010 to 22-27% by 2050. This increase in percentage intake, combined with population growth, is likely to lead to a doubling of total demand for animal-source food.
The authors conclude that Stage 5 of Popkin’s “nutrition transition” model (read more here), where diets become healthier and lifestyles become more active following Stage 4 (Western diets high in calories), cannot be seen in the data; no country has yet shown “successful policy-induced reduction of obesity, animal-source foods or food waste”. Hence, they argue, integrated policy action is needed to drive the transition to sustainable healthy diets.
The nutrition transition transforms food systems globally and shapes public health and environmental change. Here we provide a global forward-looking assessment of a continued nutrition transition and its interlinked symptoms in respect to food consumption. These symptoms range from underweight and unbalanced diets to obesity, food waste and environmental pressure. We find that by 2050, 45% (39–52%) of the world population will be overweight and 16% (13–20%) obese, compared to 29% and 9% in 2010 respectively. The prevalence of underweight approximately halves but absolute numbers stagnate at 0.4–0.7 billion. Aligned, dietary composition shifts towards animal-source foods and empty calories, while the consumption of vegetables, fruits and nuts increases insufficiently. Population growth, ageing, increasing body mass and more wasteful consumption patterns are jointly pushing global food demand from 30 to 45 (43–47) Exajoules. Our comprehensive open dataset and model provides the interfaces necessary for integrated studies of global health, food systems, and environmental change. Achieving zero hunger, healthy diets, and a food demand compatible with environmental boundaries necessitates a coordinated redirection of the nutrition transition. Reducing household waste, animal-source foods, and overweight could synergistically address multiple symptoms at once, while eliminating underweight would not substantially increase food demand.
Bodirsky, B.L., Dietrich, J.P., Martinelli, E., Stenstad, A., Pradhan, P., Gabrysch, S., Mishra, A., Weindl, I., Le Mouël, C., Rolinski, S. and Baumstark, L., 2020. The ongoing nutrition transition thwarts long-term targets for food security, public health and environmental protection. Scientific reports, 10(1), pp.1-14.
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