Vegetarian Diets and Mental Health

Its just conformity. Try to change the topic to religion, anything other than vanilla Evangelical Protestant Christian, and see how much they like it. Or, "I don't like large pickup trucks/SUVs".

(edited to add, tell them their prices are too high, if you want to tweak them back. I'm not a vegan but our family has a relationship with an organic farmer who provides us with almost all the meat we eat (other than fish), so in the very rare event I get questioned at the market my trollish side often comes out and its sometimes pretty funny)

Lots of people switch to vegetarian/vegan diets report short term (less than 5 years) health benefits. And I have no doubt these are true. Anecdotally, my couple goes at low meat/no meat diets were the same.

But most long term studies of people on primarily plant based diets show long term detriments that are double doctorate in nutrition and food science hard to eliminate.

It's a very hard pill to swallow for people who've spent considerable mental effort at designing a lifestyle around these kinds of diets, and have deeply held philosophical beliefs driving this choice.

Unfortunately, biology is an important driver here, and humans need some meat over the long term. Just not anywhere near what's common in the diets of citizens of most wealthy countries.

The good news is that we have an amazingly adaptable digestive system, capable of sustaining us on all sorts of crazy things. There's very few animals on the planet capable of sustenance from such an incredible diversity of food sources. It's no doubt one of the reasons humans have been able to spread so far and wide.

Within a remarkably short period of time, we've also been able to specialize. Humans in some corners of the world exist almost purely off of animal products while others live off of almost purely plant products, some of these populations have adapted so well they can consume dangerous levels of some nutrients or adapt to relatively low amounts of others.

A bit more on the biological specialization of humans and our evolved digestive systems.

https://news.ycombinator.com/item?id=7763330

In my case, I was spotted by guidance counselors as early as grade school for depression. It also correlated with my high test scores, creativity, and inability to focus on "boring" work.

When I became a vegetarian at age 15, it was as much a reaction to my surroundings (an Iowa farm town) and worldview as anything else. As a creative, bright, curious, kid, possibly dealing with low levels of depression, it's not too surprising that by 1986 I was a massive fan of The Smiths. The album Meat is Murder, combined with my social alienation, and not a few cows looking at me with their big ol' eyes every day, turned me into a vegetarian.

I don't think my depression increased when I gave up meat, at least not any more than it does for anyone going through their late teens and early twenties. By my thirties, life had improved, and so had my psyche. I was still vegetarian.

At age 35, I took stock of my vegetarianism, and decided I was no longer doing it for the reasons I had begun, and it had become something I only did because others expected me to. So I started eating meat. Now that I've been an omnivore for a few years, my mind works the same way it always has. With every year that I mature, things get better, but it's a trajectory I was on long before I changed my dietary habits.

I know the OP said that they were only pointing out correlation, not causation, but it seems clear to me that it's worth considering whether people who struggle with depression are turning to vegetarianism, rather than the other way around. There are so many variables and factors involved, it seems silly to make any statements about vegetarians and mental health at all, positive or negative.

Ethics aside, eating meat (at the current rate) is just not sustainable economically (unless the world's population suddenly shrinks, or the amount of resources available suddenly increases or both - significantly).

Those who care about the environment, sustainability etc should read this book http://www.amazon.com/Meatonomics-Economics-Consume-Much--Sm...

Some crazy/scary numbers from the book:

More than half the land used to grow crops in the U.S, are used to raise crops for (meat) animals.

Animal food industry is a big contributor to global warming

We've already eaten away many of the fish, and are seriously messing with the well being of our oceans

Some of the drugs used in the animal food industry, are banned in other countries (Canada, Europe etc)

And so on.

All this to say that we should carefully look at our food choices. If people want to eat meat, that's fine - we just need to make sure it is sustainable, and not cause irreversible damage to the planet. Ethics, animal suffering, cheeseburger laws...etc? That is a whole another discussion.