People decide to eat a vegetarian diet for a variety of reasons. But how they make the change requires they take one of two routes -- the overnight approach or the gradual one.

Roughly 20 million Americans are vegetarians, from partial vegetarians who limit the amount of animal flesh they eat, to vegans, who eat only plant foods -- no meat, poultry, fish, dairy products or eggs.

Vegetables are good sources of fiber, and they're chock full of vitamins and minerals.

Most nutrition experts and dietitians say that children of any age -- even infants -- can safely follow a vegetarian diet, according to the Nemours Foundation. But some planning is involved to ensure that children receive the proper nutrients, especially if their diet does not include eggs and dairy products.

If your teen wants vegetarian options, you may worry that dropping meat, poultry and fish will be unhealthy.