Any conversation on the topic of health should include some discussion of nutrition. Not all put sufficient weight to its importance, but they should. So what is good nutrition? This is also controversial, but experts agree on various fundamental principles, such as getting a balanced diet, with an appropriate distribution of the major food groups. And what is this “proper” distribution?

I have a feeling this will not be a popular subject for many readers, but the evidence is clear: Americans, as a general rule, consume far more protein than is required, certainly more than the recommended daily amounts. Perhaps this will be big news, but protein can be obtained in sufficient quantities for good health from a great variety of food sources. While protein malnutrition is a problem for millions of people around the globe, for the average adult in the U.S., far more protein is consumed than we actually need.

Most American adults eat anywhere from 100 to 250 grams of protein per day, depending on your source of information. This is approximately two to three times the recommended amount. Even on a vegan diet, people can easily get 60 to 80 grams of protein per day from foods like beans, legumes, nuts, broccoli and whole grains. Herbivorous animals don’t consume meat, yet they have the protein to build muscle and skin, bone and tendon. All of these structures are composed largely of protein: where did they get it if they don’t eat meat? The data against consistently consuming red meat (especially processed meat), and so ingesting these levels of protein, is quite strong.

But that is not the thrust of this week’s diatribe. Instead, I’d like to talk about the larger dangers of a meat-based diet. It turns out, although not often considered, some of the hazards of excessive beef consumption are having a profound effect on all of us, all the inhabitants of this planet. Whether one is a vegan, vegetarian, or a devout carnivore, we are all subjected to the behaviors of the many.

For a large percentage of Americans, a meal without meat isn’t truly a meal. Typically, some form of beef, pork or chicken is the centerpiece of the meal, be it breakfast, lunch or dinner. But how many of you think about what it took to get that steak on your plate? Somewhere the cow was “raised”, and to do that, it had to eat and drink, and perform the usual bodily functions that are part of being a warm-blooded creature. The problem arises when you have to supply sufficient quantities of carnivorous food stuffs to all the many meat-eating denizens of the planet. That’s a lot of meat.

Unfortunately, livestock farming has a vast environmental footprint. Meat production adds to environmental degradation in numerous ways. It leads to biodiversity loss, coral reef degeneration, acid rain and deforestation. Nowhere is this impact more apparent than its impact on climate change. Livestock farming contributes 18% of the human produced greenhouse gas emissions worldwide. And make no mistake about it, climate change is a threat to health, but not only due to the increased risk of extreme weather events.

Some of the environmental effects that have been associated with meat production are pollution through fossil fuel usage, effluent waste, along with water and land consumption. But the biggest concern climactically is animal methane. Methane is one of the most potent of the green-house gases and it is produced in great quantities by ruminants, which are the genus of cows, bison, deer, sheep and goats.

Although much less plentiful in our atmosphere, upon its release, methane is significantly more effective at absorbing, and therefore retaining, heat. This explains why methane is far more devastating to the environment. In the first two decades after its release, its 84 time more potent than CO2 at trapping heat. The methane from livestock has been calculated to be greater than all the emissions from all forms of transport, including cars, trucks, planes, ships etc.

When land is used to raise animals instead of crops, precious water and soil are lost, trees are cut down to make land for grazing or factory-farm sheds. More than 90 percent of all Amazon rainforest land cleared since 1970 is used for grazing livestock. Untreated animal waste pollutes rivers and streams. In fact, it has such a devastating effect on all aspects of our environment that the Union of Concerned Scientists lists meat-eating as the second-biggest environmental hazard facing the Earth.

Raising animals for food requires massive amounts of land, food, energy, and water. (Some would also venture it causes immense animal suffering.) Meat production is not an efficient process, especially red meat. To produce one kilogram of beef requires 25 kilograms of grain of feed and approximately 15,000 liters of water (although pork is less intensive than beef). It takes an enormous amount of water to grow crops for animals to eat, clean filthy factory farms, and give animals water to drink. Raising animals for food consumes more than half of all the water used in the U.S.

The scale of the problem can be seen in the numbers relative to land use: around 30 percent of the earth’s land surface is currently used for livestock farming. More than 80 percent of the corn we grow, and more than 95 percent of the oats are fed to livestock. The world’s cattle alone consume a quantity of food equal to the caloric needs of more than the entire human population on Earth. Since food, water and land are scarce in many parts of the world, livestock farming represents an inefficient use of resources. A United Nations report stated emphatically livestock farming is one of the largest sources of greenhouse gases world-wide, as well as being a primary factor leading to the extinction of many species.

Reducing consumption of animal products is essential if we are to meet global greenhouse gas emissions reduction targets. But cutting the environmental impact of livestock farming will not be easy. This will require a tremendous change in the everyday habits and practices of people world-wide. Those kinds of changes are difficult, perhaps even impossible, to come by.

Most rich industrialized countries practice higher meat consumption, predominantly red and processed meat. This type of diet is linked with poor health outcomes, including heart disease, stroke, diabetes and various cancers. Because these diseases represent a majority of the burden of global disease, reducing meat consumption can offer substantial public health benefits. Yet, it is possible we can have an even greater effect on our health and well-being by avoiding meat and dairy products: this is the single biggest way to reduce your environmental impact on the planet. Perhaps a wider perspective is necessary to see the consequences world-wide of that burger you set on your dinner table. Our food choices effect more than ourselves, they have consequences on a global scale and they don’t seem to be positive ones.

Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula, with a move of his Marquette office to the downtown area. McLean has lectured internationally on wound care and surgery, being double board certified in surgery, and also in wound care. He has a sub-specialty in foot-ankle orthotics. Dr. McLean welcomes questions or comments atdrcmclean@outlook.com.