Ask the doctors: Going vegan? Try going slowly with your shift in diet

Dear Doctors: Our 16-year-old daughter wants to become a vegan. Her father and I think that may be a bit extreme, so we’ve compromised, and first she’s going to try being a vegetarian. What’s a good way for a growing teen to safely make the transition?

A. We’re parents ourselves, so we understand your concerns about your daughter’s nutritional needs. A vegan diet, which cuts out all foods derived from living creatures — including eggs, dairy products, gelatin and honey — can send you on a steep learning curve. Even the more lenient parameters of a vegetarian diet take care and planning to be healthful and well-balanced.

As with any diet, the goal is to get enough calories, protein, vitamins and minerals from a wide array of fresh and healthful foods.

Vegetarian and vegan diets are quite popular. That means the information and products your daughter needs to be a healthy vegetarian are widely available.

As a vegetarian diet, your daughter will no longer eat red meat, poultry, fish or other seafood. Vegetarians may choose whether to eat eggs and dairy products.

We suggest a gradual transition. Instead of eliminating meat, start by adding an array of foods to your daughter’s existing diet. This includes the whole grains, nuts, beans, seeds, tofu, tempeh and seitan that can become staples of her new way of eating.

Once she’s familiar and comfortable with these, she can start eating them instead of the meat-based meal the rest of the family is having.

A vegetarian we know made an easy transition by eliminating one category of meat at a time. She started with beef and every few weeks stopped eating another type of meat. Within months, she was a vegetarian.

As a vegetarian, you want to keep an eye on Vitamin B12, which is essential to the function of nerve and blood cells. B12 also plays a role in the synthesis of DNA, and it helps prevent megaloblastic anemia, which causes weakness and exhaustion. In addition to meat and fish, B12 is found in milk, cheese, eggs and some fortified cereals. Sstudies have found that even vegetarians who consume eggs and milk can become deficient in B12, so a supplement might be a good idea.

People who don’t consume meat also should take care to get adequate calcium, iron, zinc and protein. Protein needs can be satisfied by eating a variety of grains, beans, nuts, seeds and soy products, as well as eggs and dairy products.

A few good vegetarian cookbooks can help come up with varied and healthful meals and snacks. We also think it would be wise for your daughter to meet with a registered dietitian.

Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health.