Yes, you can definitely continue on that sort of diet for the rest of your life. A high-carb vegetarian diet has been proven to dramatically reduce your chances of cancer, heart failure, and obesity.
If you’re working out, you should try and sneak in a little more protein, yes. But it definitely doesn’t require eating meat. You can get more than enough protein from tofu, legumes, and nuts. Vegetarian sources of protein have a high amount of fiber, which is terribly important. Also, NO plant foods contain cholesterol! Cholesterol is only found in animal foods, ie: meat and dairy.
As you can read in the other posts, the Atkins diet, one of the more popular “no-carb” diets, is utterly ridiculous, and you can read about where it got Dr. Atkins himself here. (Though he denies that his diet has anything to do with his heart problems, he isn’t fooling anyone. His diet is based around your body inducing keiosis, a state your body enters only when there is a huge imbalance in fat metabolism, such as either becoming diabetic, or literally starvation. Dr. Atkins has never published a single study in a medical journal, and not a single study has been published that substantiates the claims he makes. And the good doctor, who claims that he’s been on a no-carb diet for 36 years, is overweight.)
If you want a great book, which really gets into the nitty-gritty of high-carb non-meat bassed diet, check out Becoming Vegan here by Brenda Davis RD and Vesanto Melina MS RD. It’s helped me out quite a bit. I’ve been a vegetarian for 7 years, now, and am perfectly healthy. I thought I knew everything I needed to know about vegan/vegetarian nutrition, but I learned quite a bit from this book.
Another great book, which is NOT just another crazy fad diet, is Dr. Dean Ornish’s Eat More Weigh Less (click here or here for info.) It’s basically the same diet you’re already following. The book advocates eating essentially (but not literally) as many carbs as you want, as long as you stay away from animal foods and animal proteins.
Two quick important things, be sure to take vitamin B-12 supplements a few times a week. Contrary to popular belief, there ARE plant sources of B-12, but it’s a certain type of algae that you probably wouldn’t want to eat for lunch. But, many companies make vegetarian B-12 supplements. Also, as someone already mentioned, be sure to get sufficient Omega-3s and Omega-6s. Nuts, seeds, and oils are great sources of these essential fatty acids, especially walnuts, sesame seeds/oil, flaxs seed, canola oil, and pumpkin seeds.
Just to close, there are many world-famous athletes who are strict vegetarians, and eat a diet very similar to the one you described. Martina Navratilova (tennis champion), Art Still (Kansas City Chiefs Hall of Famer), Murry Rose (gold medalist Olympic swimmer), and Dave Scott (six-time winner of the Ironman triathalon).