Most of the time, practices such as vegetarianism or veganism are associated with oversimplifications such as "doing it for the animals" or even doing it because "everyone else is." Most people understand the argument for these lifestyles in terms of preventing animal cruelty, but few truly comprehend other biological benefits or reasons to do so. 

What's often overlooked is the ecological consequences of a meat-eating diet, or any animal-related diet for that matter. Yes, it seems intimidating to think of these practices from a scientific perspective, but you don't need to be a biology major to understand the basic ecological reasoning that lays the foundation for such a diet, and truly know the complete why.

pasture, vegetable, grass, kale
Maggie Finney

If anything should be taken from this article it should be this: Energy is lost with each transfer as it flows through ecosystems, while nutrients are recycled throughout. This is the basis of all ecological claims I will argue for, as it relates to energy and water conservation, toxin and fossil fuel consumption and greenhouse gas production.

For starters, just how does energy flow through an ecosystem?

Simply put, energy enters via primary producers, or plants, that create their own food, and transfers when one organism (a consumer) depends on another as a food source.

However, like everything in life, this process is far from perfect. With each transfer, energy is lost: either through heat, fuel, waste or any other metabolic processes that prevent it from being transferred to the next organism that eats it. In fact, on average, only about 10 percent is actually incorporated into an organism's biomass to become readily available as energy for the next level of consumer.

As a result, you could imagine just what happens to energy as it continues through an environment. From the original amount of energy introduced by plants, only 10 percent of that is transferred to primary consumers (such as squirrels or mice).

From there, subtract another 10 percent when those are eaten by secondary consumers like birds and foxes, and another 10 percent when these are eaten by tertiary consumers like hawks and bears and humans. By the time energy reaches the top of the food chain where higher level consumers like humans reside, roughly 0.0001% of the original energy introduced remains. Crazy right?

vegetable, grass, pasture
Jocelyn Hsu

So How Does All This Biological Information Relate?

To think of it in another way, imagine a farmer grows a plot containing 1000 kg of wheat. From that plot, 100 kg of cows can be supported, and when eaten by humans, 10 kg of that is transformed into biomass.

Out of 1000 kg, only 10 kg remains by the time it reaches us. To fuel 10 kg of human mass (roughly 22 pounds), 100 kg of cows must be produced, and 1000 kg of wheat must be grown – indicating the substantial amount of energy lost, water used and waste produced in this process.

Now, you can understand why it is more energy efficient to eat a pound of wheat versus a pound of animal meat, or to eat plant protein versus those derived from meat.

And don't just take the words of a college-level biology major like myself, because according to the Water Education Foundation, it takes 2,464 gallons of water to produce one pound of beef in California and only 25 gallons to produce one pound of wheat. For perspective, the amount of water to grow one pound of beef is the same amount of water you would use if you took a seven-minute shower every day for six entire months.

sea beet, grass, pasture, vegetable
Connie Xu

Okay, so all I've talked about is meat obtained from land, but this can also be applied to those from the sea. In a very reduced biological explanation, seafood such as crustaceans derive their heat from their surroundings and thus, unlike humans or cows or chickens, they do not need to use energy to create metabolic heat.

It follows that eating crab or shrimp over chicken or pork, actually conserves energy and resources in the environment. Even though being a pescatarian is better for the environment in that sense, think again. Because of the large amounts of greenhouse gases and wastewater generated from toxic manure, our groundwater, rivers, streams and, ultimately, the ocean are subsequently polluted.

If the ideas of conservation of energy and water, and the limitation of greenhouse gas production don't spark an interest in vegetarianism/veganism, here is one final consequence that affects a consumer like yourself directly.

Earlier, I stated that while energy is lost, nutrients are recycled as it transfers to different organisms within an ecosystem. Because certain macromolecules cannot be broken down, they increase in concentration as it flows to higher levels of consumers, since the amount of each subsequent consumer is only 10 percent of its precursor.

Macromolecules don't only include what you'd typically think as nutrients; they also include harmful substances that our bodies cannot break down, such as toxins.

Thus, eating a pound of wheat versus a pound of meat not only conserves water and energy, but also minimizes the concentration of environmental toxins you are exposed to. 

In my opinion, this explains why so many vegetarians or vegans say how much better they feel physically because they are solely consuming plants that have low toxin concentrations relative to biomass. So vegetarianism or veganism really helps their bodies.

coffee, nut
Tiare Brown

I'm not here to convince you to drastically change your lifestyle. Don't get me wrong, every once in a while, I have a serious craving for savory, roasted meat or some buttery shrimp. All I am asking you to do is take a minute to digest concepts that I have spent hours studying in biology lectures, and remember to ask yourself why. Be aware of what you fuel your body with, and how it affects those around you.