By Cynthia Sass, MPH, RD
May 10, 2011

Going veggie offers numerous health benefits, from slashing the risk of heart disease, type 2 diabetes and cancer, to capping blood pressure; and vegetarians and vegans tend to weigh less than omnivores. But done the wrong way, it can be a recipe for weight gain and shortchange you on important vitamins and minerals. To get the most from every morsel avoid these four veggie faux pas:

Overloading on Liquids

'Green drinks' are all the rage and health conscious vegetarians are often fans, but smoothies and drinks that combine veggies and fruits can easily pack 250-350 calories. To put that in perspective, for 300 calories you could eat:

1 cup raw broccoli

1 cup raw carrots

1 cup raw spinach

1 medium apple

1 cup whole strawberries

1 medium orange

The Fix: I often recommend juicing and fruit/veggie exilers for my male professional athlete clients who have a tough time fitting in the 9+ servings of produce their bodies need. But for women trying to lose weight, most feel more full and satisfied - and get better results - when they chew rather than gulp their produce.

Forgoing Protein

Protein is a key factor in weight control because it boosts satiety, preserves muscle and revs up metabolism. Because plant protein doesn't get digested and absorbed as readily as some animal proteins, vegetarians generally need more, about 15-20 percent of total calories or about 60-80 grams per day.

The Fix: Don't rely on processed meat substitutes. Instead keep it au naturel - quinoa contains 8 grams per cup; almonds 7.5 g per quarter cup, lentils 17 g per cup and if you do dairy, 1 cup of nonfat Greek yogurt packs about 20 g.

Overdosing on Cheese

Ounce for ounce, cheddar cheese packs four times the calories and nine times the fat of skinless chicken breast. That's why vegetarians who live on grilled cheese, cheese pizza and mac and cheese often gain weight going veggie (in addition to all those refined carbs, yikes!).

The Fix: If you decide to keep dairy in your diet (preferably organic), limit yourself to one cheesy meal per day with a max of 1 oz of real, fresh cheese, and stick with nonfat milk or yogurt and plenty of meatless proteins like beans and tofu at other meals and snacks.

Satisfying Your Sweet Tooth Vegan Style

There are more vegan sweet treats on the market than ever before, from cookies and cupcakes to ice creams and candies. Goodies made without butter and eggs are lower in saturated fat and cholesterol free, but they're typically just as high in calories. Case in point:

1 large vegan chocolate chip cookie = 480 calories.

The Fix: Even strict vegans should limit splurge foods to a few hundred calories per day, just like omnivores.