Three brown eggs sitting in egg container

Planet-Friendly Diet

Food production is an important contributor to climate change, accounting for about a quarter of carbon emissions globally.

Food  production  is  an  important contributor  to  climate  change,  accounting  for  about  a  quarter  of  carbon emissions globally. If Americans changed their diets by swapping out one item each day, they could reduce their carbon footprint from food, according to a Tulane study that examined the diets of thousands of people in the United States.

“We found that making one substitution of poultry for beef resulted in an average reduction of dietary greenhouse gases by about a half,” said lead study author Diego Rose, professor and director of nutrition at the Tulane School of Public Health and Tropical Medicine.

Rose  presented  the  research  at Nutrition  2019,  the  American  Society  for  Nutrition  annual  meeting,  held  in Baltimore in June.

The study is based on diet information from more than 16,000 participants in the 2005–10 National Health and  Nutrition  Examination  Survey.  A  portion  of  this  survey  asked  participants  to  recall  all  the  foods  they consumed  in  the  previous  24  hours.  The  researchers  used  this  information  to  determine  which  foods  had  the highest greenhouse gas emissions and to calculate a carbon footprint for each individual diet.

They found that the 10 foods with the highest impacts on the environment were all cuts of beef and that about 20%  of  participants  reported  consuming  one  of  these  high-carbon  foods.  Using  simulation,  the  researchers calculated  a  new  carbon  footprint for  each  diet  by  replacing  beef  with  the  closest  related  poultry  product.  For example, a broiled beef steak was replaced with broiled chicken and ground beef with ground turkey.

Animal foods are known to contribute more to greenhouse gas emissions than plant foods. Ruminant animal foods  such  as  beef  and  lamb  have  particularly  high  carbon  footprints  because  cows  and  sheep  also  release methane gas.“

Our simulation showed that you don’t have to give up animal products to improve your carbon footprint,” Rose said. “Just one food substitution brought close to a 50% reduction, on average, in a person’s carbon footprint.”