If you are looking for Vegan protein substitute, try Amazon as they have a big choice and they seem to be cheap and they are more reliable than some other websites.
Not necessarily. Sources of protein include beans, whole grains and grain substitutes, nuts and seeds. If you are not vegan you can include eggs and dairy products.
There are many vegan meat substitutes available, good for people transitioning to a vegan diet. Also there are dairy and egg substitutes for baking.
Lettuce and celery
There are a few sites that you can check. There is http://www.vrg.org, for starters. Another site you can check is www.veganproteins.com, which specifically discusses protein in a vegan diet.
My guess is that the goal is to maximize the weight-loss effects of switching to straight protein for those days, so if you can find something vegan with almost the same nutrition facts as chicken (very high protein and very low carbs) that may be worth a shot, as well. A great source for protein could be soy beans. There is a good meat substitute called 'Seitan', available at Asian food markets.
Agave nectar, brown rice syrup, maple syrup.
Celine Steen has written: 'The complete guide to vegan food substitutions' -- subject(s): Food substitutes, Meat substitutes
Some protein sources in the vegan diet are tofu, veggie burgers, and protein supplements like smoothies. There are many choices for proteins for vegan diets. Vegans can eat fruits, vegetables, nuts and grains, and many types of beans.
Yes. all vegan foods contain protein; apart from fruit and oils. If you are eating enough calories from a wide variety of foods you will be getting enough protein.
No. Casein is a protein found in cows milk.
You can find valid information from MindBodyGreen web site, www.mindbodygreen.com. You find good information also from Natural News, www.naturalnews.com.
Tofu has protein as well as nuts, rice and vegetables. There should be no reason why a vegan would not consume enough protein out of their normal foods. It should not be necessary to take supplements although these are available from most health shops.