My dad always claimed that being vegetarian was an evolved state. We went from being carnivores to being vegetarians he would argue. I don’t have a definitive view. What I do know though is if you are vegetarian, it is extremely difficult to consume sufficient protein. Your choices are limited and barring dairy products, some tofu, and maybe what you can get from nuts, seeds and lentil it is very difficult. Most forms of proteins also come with carbohydrates and if you are watching carbs, this further limits your choices. Some days you wish you were just born eating everything.
If you are strength training or engaging in any form of vigorous exercise, you may want to supplement. Whey protein shakes for example. This ensures that you end up consuming the protein that your body needs. If you do, there are a few options. Protein powder can be made at home as well. At home you can combine plant based products like chia seeds, hemp seeds and almond powder to make a protein meal. Rolled oats and almond powder mixed with whey (the liquid that forms at the top of yogurt) is another option. In desperation, I know people who even go scavenging for protein in peanuts.
If you don’t mind eating protein from a non-plant based source, you can make a powder out of collagen. Collagen is the tissue found in animals like fish. Of course, if you eat eggs, thats a good source of protein. To many vegetarians who don’t eat egg, fish or meat the choice is very limited indeed.
I think if you wish to seriously build your body, including some sources of non-vegetarian food is almost essential. I don’t know about the evolution that my dad talks about, getting sufficient protein on a vegetarian diet – is hard. There are international athletes who have done extremely well on a vegetarian diet. This includes body builders. So perhaps, all hope is not lost.