Going to school with a bunch of down-to-earth, sewed-their-own-clothes environmentalists, it was impossible not to hop on the vegan train. While this lifestyle can help you lose weight, after six years on this diet, I ended up gaining 40 pounds and realized it's because I did it all wrong. Here are my mistakes and how you can learn from them to avoid ballooning on a vegan diet.

1. Pasta and Bread Were

My Staples

On campus it was easy to grab bagels with Tofutti cream cheese for breakfast, pizza with dairy-free cheese for lunch, and a huge bowl of pasta for dinner, but I was eating enough carbs to run a marathon-while barely exercising, unless walking to the dining hall counts.

What to do instead: Overloading on carbs is one way to pile on the pounds, so while complex carbohydrates should be included in a vegan diet, they shouldn't be the star of every single meal. Head to a bookstore or the Internet to find vegan recipes, and experiment to help open up a whole new world of entrées like tofu scrambles, zucchini noodles, and homemade veggie burgers.

2. I Never Ate Beans

Having gas was the last thing a college girl would wish for, so I stayed away from beans and hardly ate any protein aside from soy ice cream. Without enough protein, hunger pangs drove me to eat more, which basically meant unhealthy comfort food like vegan mac 'n' cheese and cupcakes.

What to do instead: Be sure to stock your kitchen with vegan sources of protein such as dry or canned beans, different varieties of tofu, tempeh, seitan, soy yogurt, and soy milk. For quick meals, packaged soy burgers, hot dogs, frozen dinners, and vegan deli meats are great to have on hand. If you're not used to these foods, introduce them gradually to prevent digestive issues.

3. Sweet Potato Fries Were My Vegetable

My mom wasn't there to tell me to "eat my veggies," so guess what? I didn't-unless French fries or vegan carrot cake count. Without veggies and protein, I never felt full, which meant eating all day long.

What to do instead: Make a point to consume veggies and protein at every meal and snack, as they'll fill you up and keep you energized. Here's a sample eating schedule:

• Breakfast: this vegan, high-protein smoothie with a big bunch of spinach added

• Snack: whole-wheat pancakes made with sweet potato, topped with a dollop of soy yogurt

• Lunch: huge salad with a side of split-pea soup or buckwheat salad with tempeh

• Afternoon snack: cucumber tofu rolls

• Dinner: polenta and beans

4. I Was a Junk-Food Vegan

French fries, soy ice cream, dairy-free chocolate, vegan cookies-I was so psyched they were made without meat, milk, or eggs that I devoured them and didn't realize that they still contained calories.

What to do instead: Just as non-vegans need to enjoy treats in moderation, so do you. It's okay to indulge, but remember to mostly eat a healthy, balanced diet.

5. I Ate Peanut Butter by the Spoonful

My motto was, "If it's good for me, why not?" Unfortunately, healthy foods can also be high in calories, so downing bags of popcorn and sipping back fruity soy smoothies was one reason I didn't fit into my clothes.

What to do instead: While they're nutritious, be sure to measure out portions of calorie-dense foods such as nuts, seeds, and the butters made from them; avocado; fresh-squeezed juices; whole grains like brown rice; granola; oil; and sweet potatoes.

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