Someone qualified to be a biology teach, unless they took it upon themselves to take the extra training, wouldn’t have been trained in nutrition. What he told you is probably what he was -raised- to believe.
A vegan diet is the second healthiest diet a human being can stick to, second only to a raw vegan diet. That is only assuming you maintain a balanced diet. You can’t eat only twizzlers and oreos and assume you’re healthy because you’re vegan ;P
It’s not animal protein that we need, it is simply protein in general. The source doesn’t make a difference, however it is easier for the human body to absorb plant-based proteins.
As Annie said, an omnivorous diet is the one linked to all the health problems.
A vegan diet can actually reverse many of the ailments caused by an omnivorous diet, such as Heart Disease, high cholesterol, diabetes, and asthma.
You have been vegan for 8 months, and feel great, right?
So do the people who were raised to be vegan from birth

That is the one thing that really irks me when people claim we absolutely can’t survive on a long term vegan diet.
There are people who were raised to be vegan from birth who are healthy as can be, who have never had to go to a doctor.

My biology teacher actually told me it was a good idea to be vegan. She said in the long run it helps not only our bodies but the planet. I guess it would really depend on the person who you are talking to. Some will say veganism is bad others say that it isn’t a problem. I think you should just go with what you feel is right because in the end it is your body and health and not the other persons. Hope I helped at least a little.

I have been vegan for about eight months and I feel great being one but today when I told my biology teacher I was vegan, he got all worried and started telling me about how we need animal protein. He said that it is bad in a long term because we can’t live eating only plant based protein because it is not healthy and in a few years it will have consequences. I know that there are a bunch of rumors out there, but still he is my biology teacher shouldn’t he know the facts?
Anyway, I just want to know if it’s true because I really don’t want to go back to eating meat!!

Thanks!
Sorry that my english is not good!!