At some point in the life of parenting a tween and/or teen, he or she announces they are “going vegetarian.”

If your family isn’t already fully plant-based or at least on a minimal meat diet, this can bring out a range of emotions, including annoyance that you might have to prepare separate meals for the child, and concern that he or she will not get proper daily nutrition.

There are lots of great health and environmental reasons for transitioning to a full or partially plant-based diet. If you help your child do it thoughtfully, said clinical dietician Cathy Schneider at Backus Hospital in Norwich, they can maintain good nutrition and health.

First, some definitions. There are different types of plant-based diets:

  • Lacto-vegetarian: Excludes meat, fish, poultry and eggs, as well as foods that contain them. Dairy products, such as milk, cheese, yogurt and butter, are included.
  • Ovo-vegetarian: Excludes meat, poultry, seafood and dairy products, but allows eggs.
  • Lacto-ovo vegetarian: Excludes meat, fish and poultry, but allows dairy products and eggs.
  • Pescatarian: Excludes meat and poultry, dairy, and eggs but allows fish.
  • Vegan: Excludes meat, poultry, fish, eggs and dairy products — and foods that contain these products.

“If they just want to reduce the amount of meat they are eating, then you can easily modify recipes by substituting chopped mushrooms or beans for half the meat, for example,” Schneider said. Eggplant also works well.

The whole family can participate with “meatless Mondays” if only one or two members want to eliminate meat. When meal planning and shopping, Schneider said, make sure to buy whole grains, fruits, vegetables, nuts and seeds, beans and peas, and tofu, tempeh or soy-based products. She said non-dairy milks like almond or oat often come fortified with specific vitamins and minerals, so read labels carefully.

Schneider also said some of the “impossible” meat substitutes are also quite good. She warned that any of the frozen vegetarian options in grocery stores can be high in salt, so again, read labels.

“Make sure you are getting whole grains, and try to limit white flour and sugar,” she said.

Schneider said a vegan diet is the most challenging to ensure proper nutrition, especially for children. Pay special attention to the amounts of calcium, iron, B12 and zinc in foods.

Red flags to watch for in case your newly minted ovo-vegetarian is not getting proper nutrition:

  • Poor concentration.
  • Fatigue.
  • Low tolerance for exercise.
  • Constipation or changes in bowels.
  • Apathy.

And if your child is old enough to be trusted in the kitchen, a change to a different diet from others in the family can be a great time to help the kid learn to cook. Research recipes together.