Whether you have decided to give up meat and/or dairy products for moral and religious beliefs or a desire to lose weight and eat healthy, going vegan or vegetarian can have a big impact on your health, but it isn't necessarily all positive. Ashvini Mashru, MA, RD, LDN, a registered dietitian and author of Small Steps to Slim, finds in her practice that many new vegetarians and vegans struggle with certain nutritional deficiencies and can be just as much at risk for filling up on empty calories and processed foods as omnivores.

"I see a lot of clients who turn vegan or vegetarian to lose weight," Mashru told Philly.com. "However, although a vegetarian or vegan diet is healthy, it still has calories. It doesn't give you permission to eat a whole bag of chips or several vegan cupcakes in one sitting."

Mashru also warned though that too much of processed soy foods such as veggie burgers, just like all processed food, can be unhealthy for you because they are high in calories, fat and sugar.

According to Mashru, the major areas of concern in vegan and vegetarian diets are lack of protein, iron, zinc, iodine, omega 3 fatty acids, vitamin D and calcium.

Are you getting enough protein?
Burgers and chicken fingers don't have to be your only source of protein. Soybeans, tofu, soymilk, lentils, black beans, chickpeas, nuts and seeds, whole grains and even vegetables are all good sources of protein. But not all are considered complete proteins. For optimum health, variety in your menu is a must.

"Not all vegan sources of protein have the nine essential amino acids, but as long as you get all the essential amino acids through eating foods like legumes, beans, peas, soy and lentils throughout the day you will have enough protein," Mashru said.

Choose tall, dark and leafy
The general guideline for daily intake of fruits and vegetables is at least two servings of fruits and three servings of vegetables each day.  Mashru recommends dark green leafy vegetables, which are high in dietary fiber and rich in folic acid, vitamin C, potassium, magnesium, iron and calcium.

"One cup of raw or cooked vegetables or vegetable juice or two cups of raw leafy greens can be considered as one cup from the vegetable group," Mashru said.

The calcium conundrum
From an early age, it is engrained in us that milk and cheese are important sources of calcium, essential for healthy, strong bones. And while vegetarians can still have milk in their morning cereal and cheese on their veggie burger, vegans must find alternative sources for calcium.

"Vegans need to include fortified cereal, soy milk, orange juice and figs and beans in their diet to prevent a calcium deficiency," Mashru explained. "Collards and kale and almonds are high in calcium too."

When supplements are necessary
Certain essential nutrients like omega-3 fatty acids, iron, vitamin D, B12 and iodine, however, are particularly lacking in vegan or vegetarian diets, raising the question of whether supplementation is necessary.

Mashru said that omega 3 fatty acids, building blocks for a healthy brain and heart, can be found in avocados {also good source of protein and fiber} as well as almonds, flaxseeds, walnuts and chia and hemp seeds. She suggests sprinkling seeds on soy yogurt or having nuts or seeds as a snack or sprinkling them on vegetables to fill your daily quota.

According to Mashru though, there is still some uncertainty on whether enough EPA and DHA can be derived from vegan sources so supplementation is often recommended.

Supplementation is also recommended for iron deficiencies which can lead to anemia. Mashru however, doesn't recommend iron supplements unless they are supervised by a physician because too much iron can be dangerous. "Enough iron can be acquired in a plant-based diet. The non-heme iron in vegetables that is not easily absorbed into the body like the heme iron in meat, fish and poultry just needs to be paired with a food high in vitamin C," she said.

For best absorption of iron from natural food sources, she recommends pairings like spinach and strawberries or beans and tomatoes.

Vegans often also need vitamin D, B12 and iodine supplements.

"B12 is needed for red cells and for a healthy nervous system, but as we age, our ability to absorb B12 slows so we need more supplementation," Mashru said.

"The B12 vitamin is water soluble and easily excreted by the body so there is no concern of overdosing, but vitamin D supplements are fat soluble, and in excess amounts can cause vitamin toxicity so you have to be careful.

"Vitamin D can naturally be found in fortified soy milk and cereals and in sunlight," she added.

Iodine deficiency is another common concern, but the idea of iodine supplementation is still controversial. While iodine is an essential nutrient that protects thyroid health, not enough iodine in your diet can not only affect your thyroid function, but can cause brain damage, especially in growing fetuses and children. On the flip side though, too much can cause autoimmune thyroid disease or hypothyroidism. Good natural sources of iodine include iodized salt and sea vegetables like kelp.

Mashru said that vegetarian or vegan diets are lacking the most in immune system boosting zinc, but that natural sources are available for this too. Not only are nuts, legumes and whole grains good protein and iron sources, they also contain zinc.

Eating a balanced diet requires forethought and planning whether you are vegan, vegetarian or a meat and potatoes lover. Mashru recommends talking with your physician before starting a vegan or vegetarian diet, especially if you have a medical condition, and meeting with a dietitian or nutritionist for help with planning meals.

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