On plant-based diets

In my late twenties, I moved in the direction of eating vegetarian after studying and thinking about the issues more from a Christan perspective. My main reasons for choosing a plant based diet are:

While eating meat is clearly described as an issue of liberty (Romans 14), the Bible speaks negatively about cruelty to animals (Proverbs 12:10, Deuteronomy 25:4). Unfortunately the vast majority of meat produced in the United States comes from intensely cruel practices. Christians should not patronize this.
Hundreds of studies have demonstrated that a plant-based diet is superior for excellent health. Especially in the United States where heart-disease, strokes, and obesity are epidemics, plant-based diets are better choices to steward our health.
Since 2008, it has been more evident that world grainstocks are being depleted, which has led to elevations in grain prices which in turn is crushing the global poor. Over 70% of the grain in the United States goes simply to feed animals. By eating a plant-based diet, you put into practice "love your neighbor as yourself," especially our poor neighbors.
Few realize that influenza ("the flu") comes each year from Asia from animal farms and kills at least 30,000 people per year. Densely packed factory farms (created to satisfy our insatiable desire for meat and housing grostequely unnatural practices) breed germs like Salmonella, E. coli, and avian flu that kill thousands per year. So refraining from meat not only helps your own health, it saves others' lives. This again simply puts into practice "love your neighbor as yourself."
It is much better for the environment. A plant-based diet consumes about tenfold less resources than a typical meat-based diet.
It is the biblical ideal. History is bracketed with vegetarian periods. In Eden, God only allowed plants to be eaten (Genesis 1:29) and it was not until after Noah that eating meat was allowed (Genesis 9:3). In Isaiah 11:6-9, a world of peace is promised again. Eating a plant-based diet expresses a longing for that peaceful world.
It develops self-control, serves as a good witness, and is commended in the New Testament (Romans 14:21).

Some additional resources:

Quotations on eating vegetarian - I found these quotations to be moving and challenging.
Nutrition facts - The best website out there that accurately summarizes the medical literature to produce actionable insights. I highly recommend subscribing to the daily, free email.
Physically Addictive Foods - A funny and educational video by Neil Barnard, MD on why certain foods are addicting and how to break the addiction.
Make Yourself Heart Attack Proof - Caldwell Esselstyn MD (former Chief of Surgery at the Cleveland Clinic) gives an outstanding talk on how to eliminate heart disease
A way to reverse coronary artery disease? - For those scientifically inclined, this paper by Esselstyn gives evidence for the diet above.
Vegetarianism as stewardship - six reasons to eat a plant-based diet
Farm to Fridge - After being a voracious meat-eater for 28 years, I became more troubled that I probably would be uncomfortable with killing a cow, pig, or even a chicken myself -- yet I ate their meat all the time without thinking about it. My attitude was "let someone else do it," out of my sight. This video (a free, online stream) highlights the scarcely known problems of factory farming and the slaughterhouse industry. I wish that I watched this much earlier in my life.
Vegetarian starter kit -- practical advice on how to get started
Christian Vegetarian Association - has many valuable resources

If you have a little more time, the following books are of interest on this subject: