At Dr. McDougall's Advanced Study Weekend, I had the opportunity to hear a number of researchers and advocates make the case for a "plant-based diet", which is a diet containing little or no animal foods. Many of them voiced the opinion that animal foods contribute substantially to the primary killers in the US, such as heart disease and cancer. Some of the evidence they presented was provocative and compelling, so it stimulated me to take a deeper look and come to my own conclusions.
No matter what the health implications of meat eating turn out to be, I respect vegetarians and vegans. Most of them are conscientious, responsible people who make daily personal sacrifices to try to make the world a better place for all of us.
My Experience with Vegetarian and Vegan Diets
I've always been somewhat conscious of the food and drink I put into my mouth. When I was in college, I had a few interactions with vegetarian and vegan advocacy groups, which graphically described the inhumane horrors and environmental devastation of meat production. I didn't find those people particularly credible, so I brushed them off, but I did file their words in the back of my mind for future reference.
Graduate school was the first time I was really able to take full control of my diet, so I decided to begin thinking a bit harder about its ethical and environmental implications. I read John Robbins' book Diet for a New America, and did some additional research on my own. I quickly figured out that the vegetarian and vegan groups actually had somewhat of a point about the ethical and environmental implications of meat production. To arrive at the truth, I had to sort fact from fiction, hyperbole, and emotional appeals, but I did end up being convinced that some aspects of typical meat production are indeed inhumane and environmentally damaging. I was not convinced by the argument that meat is universally unhealthy, however.
I was mortified by the ethical and environmental implications of meat production, so I became a vegetarian, and not long thereafter, a vegan. I cooked nearly everything myself, focusing on a variety of fresh, whole foods. I was the pain in the ass who goes over to friends' and relatives' houses and refuses to eat anything that contains animal products, which I regret to this day. I remained vegan for about six months, until I became convinced that 1) not all animal foods are unethical, and 2) I had access to ethical eggs and dairy at the farmer's market. I remained vegetarian for about two years, until I decided I could also source ethical meats.
I felt just fine as a vegetarian and I didn't notice any change in my health one way or another. However, old friends who came to visit during that period did repeatedly ask me if I was sick, because of the amount of weight I had lost-- largely muscle. I had grown paler as well.
Today, I'm a happy omnivore, but I still think the ethical and environmental consequences of meat consumption are important. I don't write about them much here, because it's not my area of expertise, but they continue to impact my personal choices. If it were simply a matter of taste, I'd eat meat all day. I would love to get half my calories from meat, but I don't. I actually eat less meat than most people in the US, frequently replacing it with beans or lentils.
The reality is that meat is a resource-intensive food, when compared to most other staple calorie sources like potatoes, grains, and beans. That's why it's more expensive, per unit calorie, and almost always has been since the dawn of agriculture. That said, not all meat is equally environmentally costly. Poultry and certain types of fish are relatively efficient meats, while conventionally raised beef is remarkably inefficient. Traditional mixed farms can produce a modest amount of meat from food waste and agricultural waste-- actually increasing environmental efficiency. Simon Fairlie makes that point in his book Meat: A Benign Extravagance. But that's not how most of our meat is produced today.
In the end, we all make environmental compromises. We own houses, heat our houses, drive cars, take planes, own cats and dogs, have children, etc. Like it or not, in these situations we are sacrificing the environment for our own personal gain. The idea, however, is to make smart decisions that maximize our gain while minimizing environmental costs.
Vegetables are a good example of this. On a per-calorie basis, vegetables are environmentally costly. That's because they contain few calories, require a lot of water and nutrients, and generally require rapid transportation and refrigeration to remain fresh. Our environmental footprint would be smaller if we avoided vegetables and ate nothing but calorie-dense grains, beans, potatoes, and sweet potatoes. Yet we eat vegetables because we like the nutrition, variety, and pleasure they provide. The same is true of meat: it's not as environmentally efficient as beans, but it plays an important role in our diet.
The humane implications of meat consumption continue to guide my decisions as well. I don't buy conventional pork because it seems to be one of the least humane meats. This is both because living conditions can be inhumane, and pigs are intelligent creatures (roughly equivalent to dogs). I worry less about the living conditions of fish and poultry, although I do generally buy humane-certified products. For environmental and humane reasons, I eat more poultry and fish than other types of meat. I periodically eat grass-fed beef and lamb as well.
I don't claim to live an ethically spotless life. I could live in a lean-to without electricity, grow all my own food, and not have children. I could sell my car and stop flying on airplanes. I could turn my thermostat down another five degrees and brave the wrath of my fiancée. But I'm not going to, because I make compromises. Eating a modest amount of (relatively humane and environmentally efficient) meat is one of those compromises, and I'm comfortable with it.
I'm not going to discuss the ethical implications of meat consumption further in this series-- the rest will focus on health. I just wanted to take a moment to acknowledge that these issues are important.
What is Meat?
For the purposes of this series, meat is the flesh of an animal. That includes the flesh of mammals, birds, fish, shellfish, and insects. It also includes tissues other than muscle, such as liver.
It doesn't include eggs or dairy, although since those are nutritionally similar to meat in some respects, I'll discuss them a bit along the way.
Vegetarian vs. Vegan
In this series, I'll attempt to parse out the health impacts of eating meat. This will invoke research that focuses on omnivores, vegetarians, and vegans. These three groups differ from one another physically and physiologically in a number of ways, however vegans appear to be the most distinct.
This is probably because vegetarians eat eggs and dairy, which provide many of the same nutrients found in meat. The vegan diet is the most nutritionally distinct of the three diets.
Since the discussion will center in part around evaluating the influence of animal-derived nutrients on health, it will include vegans in comparisons when possible, rather than only comparing omnivores to vegetarians.
In the next post, I'll examine our evolutionary history with meat.