Research-Based

The Ultimate Guide to the Vegetarian Diet

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By Leslie Waterson

Reviewed by Juliana Tamayo, MS, RDN - Last Updated

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INTRODUCTION TO THE VEGETARIAN DIET

A vegetarian diet is based on eating primarily foods that come from plants, including vegetables, fruits, nuts, seeds, legumes and grains. While meat is not consumed, some vegetarians do eat certain animal products such as eggs and milk. Once considered weird and only for hippies, following a vegetarian diet is now very common. But the category of ‘vegetarian’ is very broad, with each individual choosing what to eat based on health concerns, ethics, the environment, or for spiritual reasons.

The Ultimate Guide To The Vegetarian Diet

HISTORY OF THE VEGETARIAN DIET

The principle of abstaining from eating meat has a long history. In ancient Greece, people who did not eat meat called themselves ‘Pythagoreans’ after the philosopher Pythagoras (although whether or not he ate meat is not known) and their reasons for not eating meat are the same as vegetarians today: for spiritual, ethical or health purposes. The name changed to ‘vegetarian’ in the mid-1850s when the first vegetarian society was formed in England. Not to be outdone by the British, a similar group was founded by the Americans in New York just 3 years later. It was called the American Vegetarian Society and many famous feminists joined this society, including Susan B. Anthony, Lucy Stone, Amelia Bloomer, and Horace Greeley. Many famous people in history have followed a vegetarian diet, including Benjamin Franklin, who thought a plant-based diet was both economical and humane.

VEGETARIAN DIET MACROS

There are no specific macros associated with the vegetarian diet and so it will depend on your goals. Vegetables figure prominently, but they certainly are not the only thing vegetarians eat. A vegetarian diet can be wonderfully varied. 

As with all healthy diets, getting enough protein is essential for health and also to not feel hungry. Eggs, yogurt, cheese, legumes, nuts and seeds are all good sources of protein. Healthy fats come from avocados, olive oil, butter, ghee, nuts, and nut butters. Hydrogenated oils and vegetable oils are not ideal as they have been chemically altered, but everything is up to individual choice with a vegetarian diet. As for carbohydrates, grains are best when they are whole natural, and unprocessed, but this again is a personal choice. Legumes such as beans and peas offer carbs with a hefty dose of good-for-you fiber. The best sugars are natural and come from fruit, honey and maple syrup.

A vegetarian diet will naturally be higher in carbohydrates than most meat-eating diets, but so long as they are healthy carbs such as from whole grains, legumes, and lots of fresh vegetables, and it does not have too much sugar, a vegetarian can be very healthy indeed.

BENEFITS OF THE VEGETARIAN DIET

DISEASE PROTECTION

Many people choose to follow a vegetarian diet for health-related concerns. Plant-based foods contain a lot of antioxidants which can slow or reverse many illnesses. Besides being low in fat and cholesterol, vegetables, fruits, whole grains and legumes also contain other immune-boosting vitamins, trace minerals and fiber which help protect against potentially life-threatening diseases including cancer, diabetes, cardiovascular disease and obesity, as well as chronic illnesses such as chronic fatigue syndrome and high blood pressure.

GOOD FOR YOUR HEART

Inflammation is one of the main causes of heart disease. Diets that are high fiber have been shown in studies to offer protection against heart disease, as well as diabetes, obesity, high blood pressure, and high cholesterol. A vegetarian diet is generally higher in fiber than the standard American diet.

WEIGHT LOSS

While it’s no guarantee, people who eat lots of veggies and fruit every day have a better chance of staying slim. This is because plants tend to be low in calories but are also filling (there’s that fiber again), helping you to not overeat. A diet that is mostly plant-based has been shown to reduce the risk of obesity, as well as illnesses associated with it such as cardiovascular diseases and metabolic syndrome, a precursor to diabetes.

The Ultimate Guide To The Vegetarian Diet Weight Loss

REDUCED CARBON FOODPRINT

This one is a biggie these days. Greenhouse gases are having a profound impact on our environment. Plants require fewer resources than animals to cultivate, so eating a plant-based diet helps to shrink your carbon footprint.

CLEANER EATING

The higher up the food chain you eat, the more toxins you take in because you eat whatever it is you’re eating ate. The hormones and pesticides on the feed given to the cow wind up in its meat. If you’re still with me, there’s another reason to cut back on animal protein. Meat cooked at high temperature can produce certain cancer-causing compounds. Processed meats have also been shown to increase the risk of developing cancer. 

For those concerned about protein, plants do contain protein, as well as fiber and other essential vitamins and minerals, but without the toxic side effects. A plant-based diet can strengthen your immunity, as well as slow the aging process.

BETTER DIGESTION

Numbers-wise, there are more individual bacteria in your gut than there are cells in the rest of your body. For proper digestion, you have to keep those little guys happy and fed. A high-fiber diet is good for the colon, where the colonies of ‘good’ bacteria live. Eating fiber also reduces the chances of day-to-day unpleasantness of constipation. More importantly, it lowers your risk of developing colon cancer.

Raw fruits and vegetables also contain lots of digestive enzymes. Because a vegetarian diet tends to be higher in fresh, raw fruits and vegetables than the standard American diet, it can improve digestion, which has a direct effect on overall health.

MENOPAUSAL RELIEF

Plants contain substances known as phytoestrogens, which are the plant version of the hormone estrogen. These plant estrogens can ease the symptoms associated with menopause. Things like soybeans, apples, oranges, and broccoli are high in phytoestrogens.

GOOD FOR YOUR KIDNEYS

Animal proteins are known to contribute to the formation of kidney stones, but a vegetarian diet can help reduce your risk of developing this painful condition.

DOWNSIDES OF THE VEGETARIAN DIET

CAN BE LIMITING

While vegetarian menu choices are generally available at most restaurants these days, you can run into situations where your food choices are limited, particularly if you are invited to someone else’s home for a meal.

POTENTIAL VITAMIN DEFICIENCIES

Vitamin B-12, zinc and iron can be tough to get through vegetarian sources alone. Omega-3s which come from fatty fish are another potential deficiency. Be sure to supplement as needed so that you don’t have any gaps in your nutrition.

PESTICIDE DANGER

While in theory eating a lot of fruits and vegetables is good for you, today’s commercial farming practices involve using a lot of pesticides. To keep your chemical exposure to a minimum, consider buying organic fruits and vegetables. If this is too expensive, make it a point to know ‘The Dirty Dozen’ or the 12 worse offenders for pesticide use and avoid them or buy organic.

POTENTIALLY HIGH IN SUGAR 

A vegetarian diet is a very general sort of label. It has no specific macros, calories or points to hit. Ice cream, donuts and candy are all technically ‘vegetarian,’ and vegetarian convenience food abounds.

It is all too easy to eat a diet that is high in sugar and carbohydrates and low in nutrition if you do not choose carefully.

Be sure your food choices include plenty of fresh vegetables, fruits, whole grains and legumes.

SOCIAL CHALLENGES

Whenever you limit your food choices, you run the risk of having to make difficult decisions. It can be hard to say no when the gang is going out for a burger. You may need to find new activities to do with your friends that don’t revolve around food.

VEGETARIAN DIET DETAILS

Many people already eat plenty of ‘vegetarian’ food without thinking about it: bean burritos, eggplant parmesan, cheese pizza, falafel, and vegetable stir fry to name just a few. What it means to be a vegetarian depends on your personal definition. Some people just avoid red meat and call themselves vegetarians, while others don’t eat any meat or animal by-products at all. Following are the most common types of vegetarian diets:

Pescatarian: A pescatarian diet includes vegetables, fruits, grains, legumes, and seafood such as fish, clams, scallops, and shrimp. Pescatarians might also eggs and dairy products. This diet offers more variety, and has the added benefit of animal protein that is low in cholesterol but contains omega-3 fatty acids.

Ovo-lacto: An ovo-lacto vegetarian will eat the usual vegetables, fruits, grains, legumes, and nuts, as well as eggs and dairy products. By eating some animal products, it is easier to get some of your vitamins, like vitamin B-12.

Ovo: An ovo vegetarian will eat the basics of vegetables, fruits, etc., along with eggs, but not dairy products. This may be due to lactose intolerance. Eggs contain healthy protein, fats and omega-3s.

Lacto: A lacto-vegetarian diet includes all the basics plus milk, but not eggs. Dairy products are an easy way to add calcium and vitamin D to the diet.

Vegan: Only plant-based foods are eaten. No eggs, dairy, honey, or other animal by-products.

Raw foods: All foods are eaten raw and may not be processed in any way or treated with pesticides. This means eating primarily vegetables, fruit, nuts and seeds, but it may also include raw eggs and dairy, and, sometimes, raw meat and fish.

BEST FOODS TO EAT ON THE VEGETARIAN DIET

Vegetables — Vegetables have so much to offer: vitamins, trace minerals, fiber, antioxidants, phytonutrients and other beneficial compounds, all of which are necessary for optimum health. Fresh, canned or frozen, anything goes. Eat a rainbow every day.

Fruit — Fruit is sugar the way nature intended, and it also provides micronutrients and fiber for balanced nutrition.

Legumes — Legumes are beans, such as soybeans, red beans, black beans, pinto beans, lentils, green beans and peas.

Grains — While there are no rules about grains with a vegetarian diet, wheat, corn, oats, rice, quinoa and the like are best when they are whole and unprocessed.

Fats — Again, the rules are not hard and fast here other than to avoid animal fats, but make your fats the healthy kind, such as olive oil and avocados. Depending on whether you eat animal products, butter and ghee may or may not be acceptable. Nuts and nut butters are a-okay for all forms of vegetarianism.

Herbs & spices — This is how you bring a meal to life. Don’t be shy about trying new recipes, particularly ethnic cuisine that can add a whole new dimension to your old standbys.

The Ultimate Diet To The Vegetarian Diet Foods

FOODS TO AVOID ON THE VEGETARIAN DIET

Meat — This is about the only rule that is hard and fast. Animal protein is out (except if you’re a pescatarian, in which case fish is okay).

Animal by-products — Maybe. If you’re a vegan, no dairy, eggs or other animal products.

Junk food — This counts really for everyone, but if your goal is good health, junk food should be avoided. Fill up on all those tasty veggies and fruit instead.

KEYS TO SUCCESS ON THE VEGETARIAN DIET

CHOOSE WISELY

Eat by color, not by convenience. If you find yourself stopping at the vending machine on a regular basis, carry a simple vegetarian snack of nuts or fruit to squash that bad habit.

TRY SOMETHING NEW

Don’t get stuck in a rut eating the same old spinach-broccoli-apple-banana routine. Dragonfruit, cucamelon and broccoli romanesco sound like an adventure waiting to happen. There are farmer’s markets popping up all over the place. Try something new today.

DON’T OVERDO THE SOY

Soy is a popular substitute for meat, but unfortunately a lot of it has been genetically modified. A veggie burger or dog is a nice treat, but it should not be the foundation of a vegetarian diet. Make your base vegetables, fruits, and whole grains.

DON’T BE A JUNK FOODIE

French fries and pizza are technically vegetarian. Unless you’re starving and there is literally nothing else to eat, don’t make excuses for bad eating habits.

EAT SEASONALLY

Fruits and veggies that are in season taste better because they’re fresh. They’re usually cheaper too.

LEARN TO COOK

There’s more to life than frozen pizza. Everyone should know how to cook a few basics, and vegetables and fruits are super-simple to prepare.

HYDRATE

Water is necessary for good health. Get used to carrying a water bottle with you.

BE COMPASSIONATE

Especially with yourself. A slip-up is not a total failure. You can get back on the meatless wagon at the next meal.

REMEMBER WHY YOU’RE DOING THIS

Whether your reasons are for health, the environment or spiritual, keeping the bigger goal in mind will help when temptation finds you.

COMMON MYTHS ABOUT THE VEGETARIAN DIET

PLANTS DON’T PROVIDE ENOUGH PROTEIN

Meat is not the only way to obtain protein. A 1/2 cup of beans has approximately the same amount of protein as an ounce of meat. Other than things like sugar and alcohol, most foods contain some protein. To get all your amino acids, eat a variety of high-protein foods, including nuts, seeds, beans, lentils and dairy products.

The Ultimate Guide To The Vegetarian Diet Protein

YOU WON’T HAVE AS MUCH ENERGY

400;”>Athletes like Venus Williams, Robert Parish and James Southwood seem to do just fine on a vegetarian diet. Even Tom Brady eats a diet that is close to vegetarian. If pro athletes can perform on plants alone, you should be able to too, just be sure to get enough protein and vitamin B-12.

YOU’LL DEFINITELY LOSE WEIGHT

No diet can guarantee that you’ll lose weight. Pizza, fries, chips and donuts are all technically vegetarian. You can even overdo it on healthy foods, like honey, maple syrup and nuts. Calories still matter, and so does the foods you eat. Removing meat from your diet can be a healthy step, but only if you replace it with whole, natural foods.

YOU’LL BE HUNGRY ALL THE TIME

If you feel hungry all the time on a vegetarian diet or any diet, you’re doing something wrong. The things that fill you up are fiber, fat and protein. Fiber stabilizes blood sugar which helps to reduce cravings while literally filling you up, while fat and protein are slow to digest. Nuts contain all 3 of these things and make a great vegetarian snack.

IT’S TOO EXPENSIVE

Fresh produce does cost more than pre-packaged junk food, but meat can be pricey too. Overall, vegetarian foods like rice, beans, and bread cost less than meat. Frozen veggies are fine too, and may be less expensive than fresh.

IT’S NOT SAFE FOR PREGNANCY

Experimenting with food isn’t necessarily the best idea when you get pregnant, but if you’re already a healthy vegetarian when you discover you’re pregnant, you should be fine. Since the growing fetus needs to eat too, be sure to get plenty of healthy nutrients from things like nuts, beans, and dried fruit.

COMMON MISTAKES ON THE VEGETARIAN DIET

ASSUMING ‘VEGETARIAN’ IS AUTOMATICALLY HEALTHIER

Just because something is labeled ‘vegetarian’ or ‘vegan’ does not mean it’s healthier than the food it’s meant to replace. Things like soy burgers can be highly processed, high in calories, or both. Don’t be fooled by appealing labels. Be sure the majority of what you eat is whole, natural foods.

OVERDOING THE CARBS

It’s easy to eat a bagel rather than prepare a real meal. But processed grains contain few nutrients and fiber, and the consumption of large amounts of refined carbs has been linked to an increased risk of diabetes, obesity and other chronic diseases. Take some time to plan your meals and be sure to include plenty of whole grains, such as wild rice, quinoa and buckwheat, along with fresh vegetables and fruits.

MISSING OUT ON B-12 

Vitamin B-12 is necessary for many important bodily functions. It protects your heart, your brain, your nerves and is used to make red blood cells and DNA. A B-12 deficiency can cause memory problems, numbness and fatigue. The primary source of B-12 is from animals, which includes eggs and dairy products. While some foods are fortified with B-12, if you do not eat eggs or dairy, watch your B-12 intake carefully and consider taking a supplement.

IGNORING IRON

Iron is another important nutrient most easily found in meat, and it is the kind that is easily absorbed by the body. Iron from plant sources is not as easy to absorb. Iron deficiency causes anemia, which can make you tired, dizzy, and short of breath. Iron-rich plant foods include nuts, seeds, oats, beans, leafy greens and fortified cereals. Vitamin C helps the body to absorb the iron found in plants, so be sure to eat plenty of vegetables or a piece of fruit with meals to increase your absorption of iron.

OMITTING OMEGA-3S

Omega-3 fatty acids are another essential nutrient. They reduce inflammation, offer protection against degenerative neurological diseases like dementia and lower triglyceride levels in the blood. While plants contain one type of omega-3s known as ALA, this is not the most useful to our body and it must be converted to DHA and EPA. Unfortunately, the conversion rate is low, 5% or less. Nuts, seeds, and Brussels sprouts are high in ALA, but you could also consider supplementing with a vegetarian form of omega-3s.

CONSUMING TOO FEW CALORIES

Vegetarians tend to eat fewer calories than meat eaters. While most of us could stand to eat a little less, the body still needs a certain amount of calories to function properly each day. Severe calorie restriction can have unwanted side effects, including fatigue, slower metabolism and nutritional deficiencies.

SKIPPING OUT ON CALCIUM

Most people know that calcium is essential for strong bones and teeth, but it is also needed for healthy muscles and nerves. Calcium deficiency can cause osteoporosis, a condition that causes weak, fragile bones that break easily. While dairy products are the best known source of calcium, leafy greens such as collard greens, kale and spinach contain calcium, as do almonds, oranges and figs. Some foods are also fortified with calcium.

NOT HYDRATING

Everyone needs to drink water, but for those who eat a high-fiber diet it is especially important. Water helps move fiber through the digestive tract, and prevent things like constipation, bloating and gas. Drink plenty of water throughout the day.

NOT GETTING ENOUGH PROTEIN

The body uses protein for many things: to build muscles and other tissues, to produce hormones, to create enzymes, and much more. Eating enough protein also makes you feel full, and experience fewer cravings. Protein is essential part of every diet. A diet that includes animal products makes it easy to get enough protein, but a vegetarian diet can sometimes present challenges. Be sure to eat things like nuts, seeds, beans, lentils, tofu and tempeh at every meal to meet your daily requirements.

COMMON QUESTIONS ABOUT THE VEGETARIAN DIET

WHAT’S SO GREAT ABOUT A VEGETARIAN DIET?

A vegetarian diet is lower in calories than most meat-based diets, and it tends to be higher in fiber, vitamins, and minerals. A vegetarian diet is also lower in saturated fat and plant foods contain almost no cholesterol. Eating lower on the food chain can mean fewer toxins in your system, and it is also better for the planet as it reduces energy consumption. It is cheaper and requires fewer natural resources to produce plants than it does to raise animals.

ARE VEGETARIANS REALLY HEALTHIER?

Short answer: yes. Longer answer: vegetarians have a lower incidence of cancer, heart attacks, stroke, macular degeneration, are less likely to develop type 2 diabetes, and weigh less than meat eaters. 

DOESN’T A VEGETARIAN DIET CAUSE NUTRIENT DEFICIENCIES?

Strict vegans run the highest risk of deficiencies of vitamin B-12, iron and zinc. But it is possible to supplement all of these from sources that are acceptable to vegetarians. 

IS A VEGETARIAN DIET SAFE FOR KIDS?

A diet that includes eggs, dairy products and fish can meet all of nutritional needs of a growing child. Veganism is a little tougher, and requires more planning to ensure the child gets enough calcium, vitamin D, iron, and B vitamins. It would be a good idea to consult with a nutritionist to ensure all their nutritional bases are covered.

ISN’T IT BORING TO ONLY EAT VEGETABLES?

Vegetarianism is a little bit of a misnomer because a vegetarian eats a lot more than ‘just vegetables.’ Vegetarian foods offer a wide variety of flavors. You can combine grains, nuts, vegetables, fruits and legumes in endless combinations.

The Ultimate Guide To The Vegetarian Diet Vegetables

VEGETARIAN VS VEGAN

While vegetarians will eat some animal products such as dairy or eggs, vegans avoid all foods that come from animals, including things like honey, but also gelatin, whey, casein and some forms of vitamin D-3. 

Vegetarians and vegans often oppose eating meat for ethical reasons, but vegetarians may eat eggs and dairy products so long as the animals have been treated humanely. Vegans usually oppose any use of animals, do not wear leather, and are against the use of animals for testing in science and other areas.

Nutritionally, both vegetarian and vegan diets tend to be higher in nutrients and fiber, and low in saturated fat and cholesterol than a standard diet that contains meat. However, a poor vegetarian or vegan diet could be deficient in calcium, zinc, iron and vitamin D, and other nutrients, and both tend to be low in vitamin B-12.

VEGETARIAN VS RAW FOODS

When following a diet of raw foods, at least three-quarters of the food you eat is supposed to be items that have not been treated with pesticides, refined, or processed in any way, whereas a vegetarian diet has no such restrictions. Raw foods are not supposed to been heated above 118 degrees Fahrenheit, but vegetarians are allowed to cook their food. Following a raw food diet consists of primarily eating vegetables, fruit, nuts and seeds, but it might also have raw dairy products and eggs, so long as they are organic, unpasteurized and unprocessed. Organic, raw meat and fish are also acceptable on a raw foods diet, if uncommon. Proponents of raw foods say that they detoxify your system, and that uncooked food gives your body more of the nutrients, enzymes and vitamins it needs. Taking supplements with a raw foods diet is not encouraged, but supplementing is compatible with vegetarianism. Eating whole, natural foods is definitely a step up from fast food and processed junk, but cooking, while it may destroy some vitamins, has not been proven to be bad for you, and cooking also makes certain nutrients more available. 

VEGETARIAN VS PALEO

While a vegetarian and Paleo diet shares the commonality of eating lots of vegetables and fruits, there are plenty of differences. Paleo eaters do not consume grains, and they are expected to eat meat. For Paleo, all fruits and vegetables must be fresh and found in nature, and preferably locally-sourced. The huge, hybrid fruits that are flown thousands of miles to get to your market are discouraged. Paleo also discourages eating sugars, even natural ones like honey and maple syrup except in very limited amounts. All in all, Paleo is much stricter than vegetarian.

BEST VEGETARIAN DIET SUPPLEMENTS

Vitamin B-12 — This vitamin is essential because your body needs it but cannot produce it. It supports your nervous system, and builds red blood cells and DNA.

Zinc — This mineral is also not produced by the body but it is involved in many important functions including making DNA, enzymes, growth, wound healing, immunity and synthesizing protein.

Iron — All the cells in the body contain some iron, but most of it is found in red blood cells. Its biggest job is to transport oxygen. Vegetarian diets do not always contain enough iron.

Omega-3s — These essential fatty acids do so much for the body: fight depression, anxiety, mental disorders and age-related mental decline; reduce inflammation; promote brain health; and reduce the risk of cancer, cardiovascular disease, metabolic syndrome and autoimmune diseases.

Calcium — Calcium build strong bones and teeth, but it is also needed for a healthy heart, and proper muscle and nerve function.

Vitamin D — While vitamin D can be produced by the body through the skin when it is exposed to the sun, most people do not get enough through sun exposure. Vitamin D is necessary for strong bones, but it also plays a role in immunity and protects against cancer. It is also needed to help absorb other vitamins and minerals, meaning a vitamin D deficiency can cause other nutritional deficiencies. 

VEGETARIAN DIET RECIPES & RESOURCES

The Dirty Dozen

Vegetarian Recipes

The Vegetarian Resource Group

More Vegetarian Resources

VEGETARIAN DIET STUDIES

Vegetarian Diets Linked to Lower Mortality

Vegetarian Diet: How to Get the Best Nutrition

The Oxford Vegetarian Study: an overview

PROPONENTS OF THE VEGETARIAN DIET

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Leslie Waterson

Leslie has been passionately involved in the health and fitness industries for over a decade. She is constantly reviewing the latest scientific research and studies in order to take a research-backed approach to lifestyle optimization. Her main areas of interest include nutrition and supplementation. Leslie shares her findings on Fitness Clone to help other health enthusiasts choose the products and routines that will help them achieve their goals.