Is it possible to survive on a vegan diet? The real question is, is it possible to survive on a non-vegan diet? Numerous studies have proven (not just postulated) that a lot of meat products and dairy is harmful to human health. (src: scientific studies ») You can live healthy on a vegan diet. You will probably be healthier than ever.
What about protein?
Protein only comes from meat, right? Nope. Although the meat and dairy industry would like you to believe that. Most people need no more than one gram of protein per kilogram of body weight and consume at least 30 kcal per kg of body weight. This means that we need no more than 13% of calories as protein. Very active individuals may benefit from more than one gram of protein per kg of body weight but also have a relatively high calorie intake, so 13% is also adequate for them. The old belief that grains needed to be combined with beans to create "complete" protein is now recognised as entirely unnecessary if overall protein intake is adequate.
What about calcium?
Good plant sources of calcium include tofu (if prepared using calcium sulphate contains more than four times the calcium of whole cow's milk), green leafy vegetables, seeds and nuts. The calcium in green vegetables which are not high in oxalate e.g. kale, is absorbed as well or better than the calcium from cow's milk. Some soya milks e.g. Silk+, Provamel, Plamil are fortified with calcium. Drinking hard water can provide 200mg of calcium daily but soft water contains almost none. Other calcium rich foods include black molasses, edible seaweeds, watercress, parsley and dried figs.