Reducing meals waste alone will not remedy world’s dietary wants


Reducing food waste is critical to our ability to feed the growing human population, but it won’t completely solve the problem, according to a new study based on a computer model.

Researchers calculate that the world is already producing enough protein and energy to feed 9.7 billion people – the projected population in 2050 – if food waste were cut in half. However, projections suggest that global food production will still fall short in terms of the micronutrients our bodies need to stay healthy, including calcium, iron, vitamin E, and others.

“Reducing food waste would give us enough protein and nutritional energy to feed the population of 2050 today – but not enough of the essential vitamins and minerals we need,” said Nick Smith, PhD, a research fellow at the Riddet Institute Head of study author. “This suggests that food waste is an important issue that needs to be addressed, but it will not necessarily meet all of the world’s nutritional needs.”

Smith recently presented the research at NUTRITION 2021 LIVE ONLINE.

The study is based on the DELTA model, a computational model that calculates the amount of nutrients available to the world’s population under various assumptions about population size, agricultural productivity and food waste. Designed for researchers and laypeople alike, the model calculates the nutrients available under different scenarios, taking into account waste, animal feed uses and other non-food uses of agricultural productivity. A unique feature of the DELTA model is that it not only takes into account the nutritional content of food, but also our body’s ability to use those nutrients.

“When thinking about the sustainability of the food system, it’s important to consider all aspects of sustainability: environment, economy, social, health and nutrition,” said Smith. “And nutrition is not just about having enough energy – it has to be the right foods, the right nutrition.”

One reason why reducing waste will only get us this far is because we tend to waste more of certain types of food than others, say researchers. For example, we waste around 25% of the vegetable mass after it leaves the yard gate, while that figure is around 7% with milk. In terms of nutrients, this example contributes to a higher amount of wasted fiber compared to calcium, and shows that cutting waste doesn’t have the same effects on all nutrients.

According to a recent report, about 30% of the food produced in the US is wasted every year. Food waste occurs at every point in the pipeline from farm to table, with consumer behavior making up a significant proportion. Models like DELTA can help support decision making to optimize global food systems for decades to come.

“The DELTA model was not designed to find the ‘right answer’ to what the food system should be like,” noted Smith. “Rather, it is a tool for understanding the food system, testing ideas and hypotheses, and debating. Its results are important for the global discussion about which foods the world has to produce. “