When it comes to losing weight, low-carb, gluten-free, vegan, and Paleo diets seem to get most of the attention these days.
But don’t discount a good ol’ vegetarian diet: An estimated 4.3 million adults in the U.S. consider themselves to be vegetarian, and an additional 3.7 million consider themselves vegan.
You may have heard how a vegan diet can help you lose weight. But if a 100 percent plant-based diet seems like too big of a change, a vegetarian diet can help you lose weight — if you go about it the right way.
According to the Academy of Nutrition and Dietetics, an “appropriately planned” vegetarian diet can support your health and help you drop pounds.
“’Appropriately planned‘ means that you still need to consider the foods that will make up a balanced diet – including protein, carbs, healthy fats, and the daily value of vitamins and minerals,” says Krista Maguire, R.D., C.S.S.D., and Beachbody nutrition manager.
“It means that you need to be mindful of the nutrients that are often lacking in vegan/vegetarian diets and ensure you get plenty of those with veg-friendly whole foods or supplements.”
Meat-free eaters need to be mindful of getting enough vitamin B12, vitamin D, omega-3s, iron, and zinc, she adds.
What Is a Vegetarian Diet?
A vegetarian diet excludes meat and meat by-products, such as fats like lard or tallow or broths or stocks made from meat.
While there are several subsets of vegetarianism, such a diet generally includes (but isn’t limited to) vegetables (of course!), fruits, whole grains, nuts and seeds, along with dairy and eggs.
Vegetarians don’t eat meat — red meat, poultry, fish, or seafood. Those who eat a mostly vegetarian diet with some seafood are called pescetarians.
The Different Types of Vegetarian Diets
There are different types of vegetarian diets; what they all have in common is that they exclude meat, poultry, fish, and seafood. Beyond that, here are the basic differences:
- Ovo-vegetarian: A vegetarian who eats eggs but not dairy.
- Lacto-vegetarian: A vegetarian who eats dairy but not eggs.
- Ovo-lacto vegetarian: A vegetarian who eats eggs and dairy.
- Partial vegetarian or flexitarian: A person who eats vegetarian meals more often than not. While this eating style may apply to a lot of people, someone who identifies with this diet might be making a conscious effort to reduce meat intake.
Sound confusing? There’s no need to label your chosen eating habits. “It’s not necessarily which one you choose,” says Maguire. “It’s how you implement it,” adding that you might choose one for spiritual, ethical, health, or personal reasons.
Even a partial vegetarian or “flexitarian” diet can be enough to help maintain a healthy weight. In a 2005 study of vegetarian diets, researchers found that the closer to fully plant-based the subjects’ diets were, the more likely they were to have a normal body mass index and healthy body weight.
While vegans had a “significantly lower risk of [being] overweight or obesity” (defined as a BMI of 25 or higher), even part-time vegetarians were 11 percent more likely than omnivores to have a healthy BMI.
And while BMI is not the most reliable tool of measuring health, the Adventist Health Study — published in 2013, with more than 71,000 participants — found that across the board omnivores had the highest BMIs, while vegetarians’ were lower, and vegans/strict vegetarians were again the lowest.
What’s the Difference Between a Vegan and Vegetarian Diet?
In short, the difference is whether someone chooses to eat dairy and eggs.
A vegan diet excludes all animal products, including — but not limited to — eggs, dairy, and honey.
Some vegans follow the diet for an ethical purpose and extend their exclusion of animal products beyond food, while vegans who choose to do so for the health benefits sometimes call themselves “plant-based eaters.” A vegan is also called a “strict vegan.”
Is a Vegetarian Diet Healthy?
A vegetarian diet is healthy — as long as you eat a range of nutritious foods and limit treats, processed foods, and portion sizes.
“If done appropriately, a vegetarian/vegan diet can help with weight loss because plant-based foods like veggies, fruits, whole grains, and plant-based proteins are filled with fiber and bulk that can help fill you up on fewer calories,” says Maguire.
This concept is called volumetrics. And, she adds, simply by knowing that your diet has some limitations may also help you lose weight: “You could ultimately end up eating less.”
In addition, a vegetarian diet is usually lower in saturated fats, says Mandy Enright, M.S., R.D.N., a New Jersey-based dietitian.
Less than 10 percent of our daily calories should come from saturated fat, according to the latest Dietary Guidelines for Americans from the USDA.
These fats are mostly found in animal products (as well as tropical plants like coconut and palm), so a vegetarian diet would be naturally lower in them.
And then there’s fiber, which is only found in plants like fruits, vegetables, and grains. “A lot of the plant-based proteins are also high in my favorite nutrient in the world — which is fiber! Those high-fiber diets have been shown time and time again to help with promoting weight management,” says Enright.
Fiber helps make you feel fuller longer, which means you may be less likely to snack, she adds. With a fiber-rich diet, you are creating good gut health and keeping things moving smoothly, too.
Should You Follow a Vegetarian Diet to Lose Weight?
A vegetarian diet can help you lose weight for a few reasons, says Maguire.
A healthy vegetarian diet is often lower in calories and full of that beneficial fiber, plus there are the inherent benefits of vegetables themselves. “Veggies are nutrient-packed with loads of vitamins and minerals that are necessary for proper body functions,” she says.
While a vegetarian diet can help you lose and maintain a healthy weight, you need to examine what’s motivating you, Enright says. “It has to come from the right place and right motivation, otherwise it’s not something you’re going to maintain for a long period of time,” she adds.
Oh, and if you’re worried that a meat-free diet will interfere with your fitness goals, you can relax: A 2016 study of elite endurance athletes found that a vegetarian diet did not interfere with performance — and the meat-free group had better aerobic capacity.
How to Get Started With a Vegetarian Diet
When someone wants to get started with a vegetarian diet, Enright starts by talking protein.
She then surveys what they like to eat and brings awareness to less-familiar plant-based sources of protein, like tofu and tempeh (made from fermented soybeans).
Enright also reminds them that — beyond eggs and dairy — pulses, legumes, beans, seeds, and nuts all contain protein, too, as do whole grains. This is usually the most common question people have when transitioning to a vegetarian diet.
You don’t need to make the switch overnight, either. To lose weight or reap the benefits of a vegetarian diet, there’s no set number of meatless meals you need to eat each week.
“But choosing more plant-based options more often has been shown to promote a wide variety of health benefits,” Maguire says. “There’s a movement called Meatless Mondays that has brought this idea to the attention of a wider audience. Starting with one day a week, one meal a day, then expanding as you feel comfortable can benefit anyone!”
(Pro tip: Get started with these healthy vegetarian recipes.)
Maguire recommends starting by replacing your favorite meat-filled meals with meat-free ones, such as veggie and bean chili, fajitas with mushrooms instead of beef, or pasta sauce with lentils instead of ground meat.
Explore vegetarian cookbooks and blogs, looking for meals that appeal to your palate.
“Eventually your taste buds will change, and you won’t even notice that you’re gravitating toward those veggie meals more often,” says Maguire.
4 Reasons You’re Not Losing Weight on a Vegetarian Diet
Even if your new vegetarian diet feels effortless, you may still encounter some roadblocks — including weight gain or the dreaded weight-loss plateau.
Here are four of the most common reasons why you’re not losing weight on a vegetarian diet:
1. You’re relying too heavily on carbs and dairy
Yes, cheese pizza is vegetarian, but even vegetarians shouldn’t eat it all the time.
(We know it doesn’t help matters when most vegetarian options at restaurants are some combo of carbs and cheese. During my early vegetarian years, I ate a lot of fettuccine Alfredo and grilled cheese sandwiches.)
Dairy is rarely considered a protein in most meal plans — if you’re following the Ultimate Portion Fix nutrition plan, only cottage cheese, ricotta, and yogurt are proteins — but new vegetarians make the mistake of loading up on cheese to replace meat as a protein source.
(Ultimate Portion Fix treats cheeses like Parmesan, feta, and mozzarella as Blue containers, or healthy fats.)
When choosing carbs, follow the same strategies you would for a non-vegetarian diet, focusing on complex carbohydrates from whole-food sources like starchy vegetables and whole grains (rather than refined flour).
A vegetarian diet, versus a vegan diet, opens up “more options for higher-protein foods like eggs and Greek yogurt,” says Maguire. “There is research showing that higher-protein, lower-carb diets can be beneficial for weight management.”
Pro tip: Rather than leaning on carbs and dairy (especially when eating out), lean toward vegetables, legumes, and whole grains, with some dairy for added flavor.
2. You’re ignoring portion sizes
When it comes to the plant world, most options are less calorie-dense than animal foods, but “some of them are dense calories (as I finish licking my spoon of almond butter!),” says Maguire. Calories still count, and portion sizes still matter.
“There’s a false sense that all vegetarian foods are healthy, and newbies who follow this diet tend to overeat and end up gaining weight,” she adds.
She knows this from experience — at the beginning of the 6 years she spent as a vegan, she gained weight. “I was eating a lot of nuts, nut butters, carb-heavy foods, and whatnot without thinking about total calories.”
Pro tip: If you’re struggling to keep portions in check, try a program like Ultimate Portion Fix or 21 Day Fix.
“If you’re vegetarian, you can do a hybrid of the regular plan and the vegan,” says Haynes. “I often recommend following the vegan plan and then making some of your reds eggs, yogurt, or whatnot if those are foods that you include in your diet.”
3. You’re trying to create a meat-free version of a traditional diet
When you’re simply swapping in faux chicken nuggets, beef crumbles, and hot dogs for the meaty versions, you’re still eating a lot of fat, salt, and even sugar.
“There are healthy ways to make foods that resemble the animal-based foods you once ate,” says Maguire, like black bean burgers, jackfruit “pulled pork,” and tempeh bacon.
“You just have to make sure that the ingredients used are all whole-food ingredients. A lot of the prepackaged foods like soy dogs, faux bacon, some veggie burgers, etc., are made with ingredients that are probably even worse for your health than the real deal – meaning the meat it’s trying to replace,” she explains.
Pro tip: “I encourage those who are vegetarians or vegans to make most of their diet actual veggies instead of faux meats and processed packaged foods,” Haynes says.
Rely on whole foods most of the time, and use those other processed foods as your treats no more than 10 to 20 percent of the time, “but know that just because they’re not meat, that doesn’t mean they are health foods,” she adds.
4. You assume that just because it’s vegetarian, it’s healthy
In addition to fake meats, the lure of vegetarian treats can be strong. After all, banana bread, cupcakes, and ice cream are all vegetarian.
“Just because it’s vegan/vegetarian doesn’t make it healthy,” reiterates Maguire. “I like to use the example of Oreos and French fries. Both are vegan but obviously not health foods that promote weight loss!”
Pro tip: As with the meat swaps, consider treats to be an exception to your healthy vegetarian diet rather than the rule. Limit them to no more than 20 percent of what you eat.
The Bottom Line
A vegetarian diet can help you lose weight — but only if most meals and snacks you’re eating are made with whole foods.
If you feel motivated to give up meat, know that you can still achieve your fitness and weight-loss goals, so try a few meatless meals and build from there.