Researchers say monetized health benefits of shift to less or no meat, more plant-based diets could rival the climate change benefits

March 25, 2016

Researchers used a computerized model to examine the outcomes of four dietary scenarios, both in different regions of the world and the planet as a whole, by 2050. The four scenarios are:

  1. A “business as usual” approach based on predictions from the Food and Agriculture Organization of the United Nations; this scenario was used as the reference point for the study
  2. A “healthy global diets” scenario in which people adopt the global dietary guidelines for healthy eating and consume just enough calories to maintain a healthy body weight; it includes at least 5 servings of fruits and vegetables, less than 50 g of sugar, and a max of 43 g of meat daily
  3. A vegetarian diet that includes eggs and dairy, 6 servings of fruits and vegetables, and 1 portion of pulses
  4. A completely plant-based vegan diet, with 7 servings of fruits and vegetables and 1 portion of pulses

“The three non-reference scenarios are not intended to be realizable dietary outcomes on a global level but are designed to explore the range of possible environmental and health outcomes of progressively excluding more animal-sourced foods from human diets.”  The outcomes show that eating fewer animal-sourced foods could make a big difference in a lot of ways.

First, humans would be healthier. Adoption of the “healthier global diet” by 2050 could save 5.1 million deaths per year, with 7.3 million lives saved by vegetarianism and 8.1 million for veganism. This is because eating less meat reduces the prevalence of chronic, non-communicable diseases associated with high body weight and unhealthy diets, primarily in developed countries.

Second, dietary changes toward less animal-sourced foods can help mitigate an expected growth in food-related greenhouse gas emissions. The Washington Post reports:  “With the healthy diet that still contained some meat, global greenhouse gas emissions from the food sector only increased 7 percent by 2050, compared with an expectation of a 51 percent increase under business as usual. Again, the vegetarian and vegan diets had even sharper (positive) effects on emissions.”

Third, there would be economic benefits due to lower healthcare costs and fewer lost workdays associated with deaths from specific diseases caused by poor diet, adding up to an impressive savings of between $700 and $1,000 billion annually.

graph from meat study

© PNAS – Graph shows economic, healthcare, and environmental benefits of eating less meat. HGD – health global diets, VGT – vegetarian, VGN – vegan

Climate change presents other obstacles though; climate change is already severely impacting some of the world’s prime fruit and vegetable growing regions (California is one) through drought. Both for health purposes and climate, incentives for growing fruits and vegetables would have to expand and climate change should be halted.  A much greater quantity of fruits and vegetables would have to be available – a 25 percent increase for the healthy global diet, with 56 percent less meat – and higher yet for the vegetarian/vegan scenarios.  Janet Riley, senior vice president of the North American Meat Institute, expressed their disagreement with the study and its premises.

The per capita impacts of dietary change would be greatest in developed countries. The monetized value of health improvements could be comparable with, and possibly larger than, the environmental benefits of the avoided damages from climate change.

http://www.pnas.org/content/early/2016/03/16/1523119113.full