Ever since I've read the book, "The China Study," I've experimented with lowering my animal protein intake and upping my vegetables. If you haven't read the book, what it essentially says is that the lower your intake of animal proteins, the lower your risk for cancer, heart disease, diabetes and a whole slew of other diseases. It provided some very compelling evidence, compelling enough for me to reevaluate some of my assumptions as a former bodybuilder of ten years who ate 5 times a day of high protein (all animal) meals.
every so often, I get the question from vegetarians, "Can I build muscle as a vegetarian?"
My answer: NO, you cannot build a large muscular physique without animal proteins. Animal proteins don't just include beef, pork, poultry, and fish, but they include anything that comes from an animal: eggs and dairy.
The key word is can you BUILD muscle without animal proteins? Try it on only soy, beans and nuts, and you will not build a yoked out physique at all. You can build an impressive physique that is trim and lean IF you strength train, but your muscles will have a soft and stringy look to them. But big, buff, and dense muscles? NO.
Now a lot of people point to vegetarian bodybuilders such as Bill Pearl and others, but I'll tell you this: Bill Pearl built an impressive muscular physique with animal proteins and THEN became vegetarian. afterwards, he still ate eggs and dairy.
Having experimented with a near vegetarian diet, I will tell you this: it is much easier to maintain a muscular physique on a vegetarian diet AFTER you've built it on a diet chock full of animal proteins. And even then you will lose muscle density on a vegetarian diet. plus you will experience poorer recovery from workouts and more aches and pains.
However, your cardiovascular health will be much better. Rather than having an brawny physique, my physique is now trim and lean. but that is only because I am still strength training heavily, not running and yoga.
Plus I still eat animal proteins, but I practice what is known as "protein-pulsing." Rather than constantly eating a steady flow of animal proteins every few hours every day, I gorge on protein once a day. This is the way animals eat, and predatory animals such as tigers and leopards can maintain a very large and impressive musculature on that.