Transition to vegan diet should be gradual


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?

Dear Reader: We’re both parents ourselves, so we understand your concerns about meeting 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. The good news is that vegetarian and vegan diets are quite popular. That means the information and products your daughter needs to be a healthy vegetarian are widely available.

When following a vegetarian diet, your daughter will no longer eat red meat, poultry, fish or other seafood. Vegetarians may choose whether or not to eat eggs and dairy products. (Some, referred to as pescatarians, include fish in their diets.)

Although it can be tempting to dive into the deep end with a new lifestyle choice, 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 tofu, tempeh, seitan, beans, legumes, nuts, seeds and whole grains that will become staples of her new way of eating. Once she’s familiar and comfortable with these new foods, 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 a few months, she had achieved her goal of becoming a vegetarian.

Elizabeth Ko, MD and Eve Glazier, MD

When it comes to nutrition, you want to keep an eye on B12, a vitamin that’s essential to the proper function of the body's 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. Several studies have found that even vegetarians who consume eggs and milk can become deficient in B12, so a supplement may be a good idea.

People who no longer consume meat also have to take care to get adequate calcium, iron, zinc and protein. Protein needs can be satisfied by eating a variety of beans, legumes, nuts, seeds and soy products, as well as eggs and dairy products.

A few good vegetarian cookbooks will be essential tools for coming up with varied and healthful meals and snacks. We also think it would be wise for your daughter to meet with a registered dietitian to learn the nutritional guidelines of her new lifestyle.

(Send your questions to [email protected]. Owing to the volume of mail, personal replies cannot be provided.)