A person should eat what will make them healthy mentally and physically, but just what that is can be influenced by many things, one of them being attacked by people claiming that eating meat isn't healthy for mind and body, ecologically-responsible and ethical. Such accusations contribute to a world that already has enough problems and negativity. Lets' look at those claims more closely.
Begin by looking in the mirror. We have eyes in the front of our heads, like carnivores and omnivores, to look for food, and we have some canine teeth. Herbivores, in contrast, have eyes on the sides of their head to look for predators and do not have canine teeth. Our physical nature then is that of a meat-eating omnivore, like a bear, or chimpanzee.http://www-bcf.usc.edu/~stanford/chimphunt.html
If you eat meat, someone has to kill the animals. In addition to farming, the ethics of hunting have also been challenged by anti-hunters despite the fact that most all of the best-respected behavioral scientists of the last century, including Sigmund Freud, William James, Carl Jung, Erich Fromm, Marie-Louise von Franz and Karl Menninger, wrote that hunting is a natural, healthy part of human nature; a very basic instinct programmed into our species for survival purposes that enables us, even in an age of technology, to continue to accept and express our basic biological identity, which is beneficial for mental and physical health.
In his highly-acclaimed book about the causes and prevention of violence, The Anatomy of Human Destructiveness, psychologist Erich Fromm wrote that, "In the act of hunting, the hunter returns to their natural state, becomes one with the animal, and is freed from the burden of his existential split: to be part of nature and to transcend it by virtue of his consciousness. In stalking the animal he and the animal become equals, even though man eventually shows his superiority by use of his weapons." In short, ethical hunting is also good for the soul.
Wearing my psychologist hat, I conducted a search of the ProQuest Psychology search engine that indexes more than 400 journals in the fields of anthropology, psychology and psychiatry. The Search Engine found 258 articles that used the word "hunting." None of these studies report that there is any correlation between ethical hunting and psychopathology. I also spoke with the Research Department of the American Psychological Association. They were not aware of any studies to support the claim that hunters in general are prone to mental illness.
When University of Nebraska-Omaha criminologist Chris Eskridge compared hunting license sales with violent crime rates on a county-by-county basis throughout the United States, he found a significant inverse correlation: as hunting license sales go up, violent crime goes down. Eskridge concluded that hunting serves as an outlet for stress and tension that otherwise could contribute to violent behavior.http://www.upi.com/Archives/1985/03/29/Study-hunting-offers-emotional-release/6786480920400/
Concerning what diet is best for you, then, consider these scientifically supported facts.
Some people seem to be healthy following a vegetarian diet, great, but in the widely acclaimed book on diet and exercise, The Paleolithic Prescription, which traces the history of human diet for thousands of years and started the whole "Paleo" diet movement (which was the most popular diet in 2013), Emory University professors S. Boyd Eaton, M.D., Melvin Konner, MD, and nutritionist Marjorie Shostak find no historical evidence to support the position that meatless diets will make humans live longer, be stronger, or even less violent. In fact the opposite seems true.https://authoritynutrition.com/5-studies-on-the-paleo-diet/
And, there is considerable research to support the very popular Paleo Diet, which was inspired by the Eaton, Konner and Shostak book. https://authoritynutrition.com/5-studies-on-the-paleo-diet/
Opposition to eating meat is often based on moralistic reasons. While all religions support reverence for life, there is only one major religion, Jainism, that strictly forbids eating meat. Certain casts of Hindus don't eat meat, however 70% of East Indians still include some meat in their diet, and some Hindus practice animal sacrifice.
Vegetarianism gets a lot of positive press, but a study by Vegetarian Times, finds that only 3.2% of U.S. adults at any one time follow a vegetarian-based diet. Approximately 0.5 %, or 1 million, of those are vegans, who consume no animal products at all. Other studies conclude that more people say they are vegetarians than actually eat no meat, and so the actual number of vegetarians in the US is only about 2%.http://www.ncbi.nlm.nih.gov/pubmed/15896441
There are at least twice as many hunters as vegetarians and four times as many fishermen!
Even more important, in a 2014 article, Dr. Hal Herzog, Professor of Psychology at Western Carolina University reports that 84% of vegetarians and 70% of vegans return to eating at least some meat.https://www.psychologytoday.com/blog/animals-and-us/201412/84-vegetarians-and-vegans-return-meat-why
Herzog and a colleague did a study of vegetarians who return to meat eating and found that 35% of the participants indicated that declining health was the main reason they reverted back to eating meat.http://posters.isaz.net/posterDisplay.php?posterID=47
There are some notable converts to meat-eating. Some Buddhists do not eat meat, but the Dalai Lama eats meat, at the urging of his doctors.https://www.thestar.com/news/world/2010/10/16/the_dalai_lama_is_a_meateater.html
In Tibet, most Buddhists eat some meat, and a few years ago I helped produce a concert by the Buddhist Gyuto Monks chanting singers. When asked what they wanted for dinner before performing, the monks ordered Big Macs.
The popular holistic physician Dr. Andrew Weil once was a vegetarian but has become a piscatarian, someone who eats fish – especially deep water fish such as salmon, halibut and cod -- because he could not get enough protein as a vegetarian.http://www.drweil.com/drw/u/QAA401090/Flexitarian-or-Vegetarian.html
Another physician and author of several books on health and diet, Elson Haas, MD, has followed a similar path that led him to include cold water wild fish and fowl in his diet as he also decided that he needed more protein. http://www.shareguide.com/Haas.html
Some animal rights vegetarians call hunters and meat eaters crazy and mentally ill. Psychological research does not support that ethical hunters are at all associated with mental illness, and a study conducted in Germany that compared 54 completely vegetarians and 190 predominantly vegetarians with 3972 non-vegetarian participants found that: "Vegetarians displayed elevated prevalence rates for depressive disorders, anxiety disorders and somatoform disorders. The findings cannot be explained by socio-demographic characteristics of vegetarians (e.g. higher rates of females, predominant residency in urban areas, high proportion of singles). The analysis of the respective ages at adoption of a vegetarian diet and onset of a mental disorder showed that the adoption of the vegetarian diet tends to follow the onset of mental disorders. … However, there was no evidence for a causal role of vegetarian diet in the etiology of mental disorders."http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3466124/
In a related study last year Australian researchers revealed that vegetarians reported being less optimistic about the future than meat eaters. What's more, they were 18% more likely to report depression and 28% more likely to suffer panic attacks and anxiety. "We don't know if a vegetarian diet causes depression and anxiety, or if people who are predisposed to those mental conditions gravitate toward vegetarianism," says Emily Deans, M.D., a Boston psychiatrist who studies the link between food and mood.http://articles.mercola.com/sites/articles/archive/2011/10/29/why-are-vegetarians-at-risk-of-heart-disease.aspx
So, what diet is right for you?
Obviously, check with your doctor, but the research of Dr. Peter D'Amato reported in his best-selling book, Eat Right for Your Type,http://www.dadamo.com/
concludes that your blood type may be a key to a healthy diet.
Type O's tend to be mesomorph in physique (muscular and more athletic), and need meat-rich diets. The type of meat is open to personal choice, but D'Amato feels that Type O's need at least some red meat.
Blood Type A's are ectomorphic (more slender) and evolved later in areas of the world with relatively little meat, and may do okay on vegetarian diets with care to get enough protein.
Type B's evolved in the plains of Mongolia and need meat, but less red meat. Chicken, lamb and fish would be optimal for their diet.
How you get your food is also important to mental health. Environmental education research shows that a person who participates in the harvest of some of their own food is likely to develop a sincere appreciation for nature and conservation, as well as understanding your place in the food chain, (http://www.colorado.edu/cye/sites/default/files/attached-files/Chawla%2C%20L.%20%281998%29.%20Significant%20life%20experiences%20revisited.%20Journal%20of%20Environmental%20Education%2C%2029%283%29%2C%2011-21..pdf
>link) that inspire what Aldo called an "Ecological Conscience." In short, getting your hands dirty and bloody gathering your own food results in significant life experiences that are good for you and conservation.
Some of the best environmental education programs these days are the "Salmon In The Classroom" programs where kids raise salmon and trout in their classes, release them into nature, and then catch and eat some of them, as well as harvest others to keep the program going and the runs healthy. http://www.adfg.alaska.gov/index.cfm?adfg=educators.salmonclassroom
As a final thought, in keeping with the value of the psychology of ethical hunting, in the The Paleolithic Prescription, Eaton, Shostak and Konner (a psychiatrist), observe: "Our ' hunting instinct' has gone awry in 'civilized' society, where the thrill of the chase and the kill are no longer part of our experience and there are no clear avenues of expression except, perhaps to our peril, in the streets and subways of today's urban jungles."
--James Swan, Ph.D.