Is it a sin of being a vegan or a vegetarian because, my dad want me to still eat meat despite the fact I very healthy now and I don't want to go back to my old fast food diet now. I know the bible said "Thou shall honor your mother and father," but I want to remain a vegetarian to help the animals, earth, health, and end world huger. What shall I do?
Being a vegetarian or vegan is not a sin. The Bible does not say you have to eat meat (unless you are Jewish, in which case you are required to eat lamb at Passover). Nor does choosing to be a vegetarian dishonor your parents. You may, in some cases, choose a different life than your parents would like, without dishonoring them. It would only be failing to honor them if you spoke disrespectfully in standing up for what you believe in. Otherwise, I fail to see how not eating the same foods as your parents would be failing to honor them, unless perhaps your parents are butchers or raise animals for food.
God did say in Genesis 9:3 that man is allowed to eat meat of animals. It is not a sin to eat meet. Failing to eat meat could only marginally be called “helping” animals, but it certainly is not harming them. It may or may not help the earth; many would say it would be ecologically incorrect to be a vegetarian. I do fail to see how your being a vegetarian would help end world hunger, other than that it would allow others to eat the meat you choose not to. (And I don’t mean that to sound like I am making fun of your decision. I am not intending to do so.) As to health, there is much debate about the health benefits of vegetarianism. There are certain vital amino acids, for instance, that can only be produced when eating animal products. There are many people who eat meats of various sorts that are as healthy as many vegetarians, and there are many vegetarians who are as sick as many who eat meat. There is nothing wrong with you choosing to be a vegetarian. I am just pointing out that the reasons you give are not necessarily valid reasons to do so.
I cannot tell you what you should do. I am not a counselor. I can only tell you that it is not wrong to choose not to eat meat, and that “honor your father and your mother” does not necessarily imply that you are to obey them in all things.