About 8 million Americans consider themselves vegetarians, and an increasing number of them are young people -- often the children of vegetarians or kids who've decided to become one on their own.
But some question whether vegetarianism is a healthy diet for a growing child.
There are many reasons why teens choose a vegetarian lifestyle, including health concerns and love for animals. Whatever the reason, their numbers are surprisingly high, especially for girls.
The American Dietetic Association estimates that a whopping 11 percent of girls, ages 13 to 17, have given up meat and meat products.
Fifteen-year-old Katie Mayer is one of them.
Initially, Mayer's mother, Karen, was concerned about her choice.
"I had a bit of dread at first -- wondered how to get enough protein into her," said Karen Mayer.
After all, Katie is in her prime growth years, when protein is a key to healthy development, and animal products are a prime source for most people.
"Protein is the most important nutrient besides water. If you're not getting enough it can stunt your growth, you are prone to illness because protein is necessary for the immune system," said Katherine Tallmadge, with the American Dietetic Association. "You can die without enough protein."
A typical teen needs 15 to 20 grams of protein per meal. Soy and tofu have protein too, but not the same levels. So teens looking to lose weight and still get protein should know there can be a calorie cost.
"There is no guarantee that vegetarians will lose weight," Tallmadge said. "For example, three ounces of lean meat has 21 grams and 150 calories. But it would take 15 ounces of tofu to get the same amount of protein, and the calorie count rises to 322."
When Katie first embraced a vegetarian lifestyle she ate mostly pasta and spaghetti. Now, she prefers veggie burgers.
After a meatless year-and-a-half, both Katie and her mom are doing better, but it's been a team effort.
"It takes more creativity. I read vegetarian cookbooks -- I put a multivitamin in her too," said Karen.
Talmadge said coordination between teen vegetarians and their parents is a key to staying healthy, and the Mayers are on the right track.
"Anytime a teen decides to make a major change in diet, you need to look into it," she said. "A vegetarian diet can be one of the most healthy diets on the planet, but it has to be done correctly."