A new study suggests that sticking to an all-vegetable diet could be harming the environment.

According to the researchers who carried out the study, this is due to the amount of resources needed to produce certain types of vegetables and fruits, Science Alert reported.

Due to the effects of global warming on the planet and the known health benefits of sticking to a vegetarian diet, calls have been made for the public to refrain from consuming meat. Aside from the health-related implications, it is believed that doing so can also help the environment.

The U.S. Department of Agriculture even recommended that people should increase their daily intake of fruits and vegetables.

But, in what seems to be a response to the USDA's current dietary guidelines, researchers from the Carnegie Mellon University recently released a study indicating how sticking to a meat-free diet could actually affect the environment.

For their report, the researchers based their findings on the energy costs, water use and emissions that are involved in producing different kinds of food items. They discovered that some vegetables, such as lettuce, actually produce more greenhouse gas than meat.

"Eating lettuce is over three times worse in greenhouse gas emissions than eating bacon," researcher Paul Fishbeck said in a statement. "Lots of common vegetables require more resources per calorie than you would think."

"Eggplant, celery and cucumbers look particularly bad when compared to pork or chicken," he added.

Despite the findings of the study, the researchers noted that the public should not interpret the results of the report as a clear indication that vegetarianism is bad for the environment. Instead, the researchers are more concerned about the implications of the USDA's dietary recommendations since increasing one's daily intake of dairy, vegetables, fruits and seafood would result to a 38 percent spike in energy consumption.

"What is good for us health-wise isn't always what's best for the environment," Michelle Tom, the co-author of the study said according to The Daily Meal. "That's important for public officials to know and for them to be cognizant of these trade-offs as they developer continue to develop dietary guidelines in the future."

The researchers also noted that the production of certain meat products can also take a toll on energy use, which also contributes to carbon emissions.

The findings of the researchers were details in a study published on November 24 in the scientific journal Environment Systems and Decisions.