When I switched cold-turkey (pun alert!) from a meat-eating to a vegan diet, I was pleased to see I could still eat fries, chips and salsa, and my secret guilty pleasure, Swedish Fish (it’s not real fish, you see). But I quickly realized I'd stumbled into a common veggie pitfall -- eating junk food in place of fresh, whole, plant-based meals.

Here, I'd adopted a vegetarian diet for health reasons but was barely eating my good-for-me vegetables. I started experimenting with vegan and vegetarian cooking, and my mind -- and my palate -- quickly opened up to a delicious world of whole grains, legumes, vegetables, nuts and fruits. A good, healthy mantra for anyone is "all things in moderation." Jumping into a junk-food vegetarian diet without any balance was definitely not that.

If you're new to vegetarianism or looking to test it out, don't make my same mistakes. Here are common pitfalls to avoid.

When you switch from meaty to meat-free meals, you reduce your total protein intake (remember meat is a primary source of protein for most folks). But don’t get lazy and forget to add back an alternative protein source. Eating protein builds, repairs and maintains your muscles; it also keeps you feeling satisfied. Everyone's protein needs vary -- depending on our age, size and activity level. To estimate yours, multiply your body weight in kilograms by .8, or weight in pounds by .37. Beans, legumes, tofu and nuts are all great protein alternatives. I like to boost my spaghetti and sauce with white beans instead of meatballs -- or for something like stir fry, I’ll swap the chicken for tofu.

I’ve actually met vegetarians who don’t eat vegetables and can survive on grilled cheese and onion rings alone! I guess there is a vegetable lurking in that order of onion rings, but nothing nutrient-rich, for sure. You can eat a bread-, pasta-, fries- and cheese-based diet every day, but that’s not exactly healthy. Even actress and Jenny Craig spokeswoman Kristie Alley fessed up to her own bad habits and told People: “For seven months I was a vegetarian, and I can't tell you how much weight I gained being a vegetarian! A vegetarian would probably be eating vegetables. But to me being a vegetarian meant I'm going to eat enchiladas with no meat, and I'm going to eat lots of bread, lots of carbs.”

Cheese quesadillas, French fries, ice cream, pizza, nachos and candy -- what do all of these foods have in common? They’re all junk foods, they’re often on fast-food menus and they’re all vegetarian (though not always vegan). When eating out, plan ahead by reviewing restaurant menus for healthier choices. A veggie burger may sound nutritious, but smother it in cheese and that sandwich could have more calories and fat than a beef burger. Sure, fried foods and cheesy snacks have their place (always in moderation!), but make sure that’s not all you’re eating.

Okay, so you’ve swapped your ballpark frank for a soy corn dog and chicken nuggets for soy nuggets. These meat-replacement products are still processed. Eyeball the ingredients list -- they tend to be pretty long and contain chemicals, additives and lots of words you can’t pronounce. Vegans beware: some of these meat substitutes actually contain animal ingredients such as egg whites, cheese and dry milk. Experiment with whole-food protein sources, such as tofu and beans, instead. Use seasonings and marinades to jazz up baked tofu slices. Make your own veggie burgers with mashed chickpeas or grated veggies. I just made this great Bulgur Burger with Chickpeas and Tomato Chutney (shown above, served with kale, spinach and collard greens sauteed in olive oil over a piece of naan bread).

Following a vegetarian diet takes some extra planning to make sure you keep it healthy, but it doesn’t have to be complicated. Check back each month for my new series, "The Veggie Table" (get it?), and I'll share my veg-friendly ideas and recipes so we can avoid meat-free mistakes together!

Janel Ovrut, MS RD LDN, loves experimenting with vegetarian and vegan cooking. Read her food blog, Dine Dish Delish, and follow her on Twitter @DietitianJanel.