Plant Based Foods & Applicable Diets
It’s appropriate to define exactly what the terminology “plant-based eating” refers to?
Simple question but actually, I cannot oblige with a straight forward answer. The term ‘plant based’ can refer to a variety of dietary approaches from vegan, to vegetarian or even ‘flexitarian’ approaches.
Essentially, we’re talking diets that put plants (fruits, vegetables, legumes, grains, seeds & nuts) front & centre.
This includes people who may embrace a:
Vegetarian Diet:
A vegetarian diet is one of the three healthy eating patterns highlighted in the 2020-2025 Dietary Guidelines for Americans. In fact, vegetarianism has been practiced for centuries in various civilizations around the world, with written references going as far back as the sixth century AD in Europe. At its core, a vegetarian diet omits meat, poultry & fish. However, there are several types of vegetarian diets that have additional allowances &/or restrictions. This article will focus on the different types of vegetarian diets, explore research around the benefits of a vegetarian diet & underscore the nutrients that vegetarians should ensure they get enough of.
Types of vegetarian diets:
There are several varieties of a vegetarian diet, including:
• The lacto-ovo-vegetarian diet: Eliminates meat, fish & poultry but allows eggs & dairy products.
• The lacto-vegetarian diet: Eliminates meat, fish, poultry & eggs but allows dairy products.
• The ovo-vegetarian diet: Eliminates meat, fish, poultry & dairy products but allows eggs.
• The pescatarian diet: Eliminates meat & poultry but allows fish; sometimes allows eggs & dairy products.
• The vegan diet: Eliminates meat, fish, poultry, eggs & dairy products, as well as other animal-derived products such as honey.
Some diets are not considered vegetarian but share overlapping principles. One example is the flexitarian diet, which is a flexible eating style that emphasizes the addition of plant or plant-based foods & beverages, incorporates dairy & eggs & encourages meat to be consumed less frequently &/or in smaller portions.
What Foods Make Up a Vegetarian Diet?
Despite there being different kinds of vegetarian diets, the following types of foods are emphasized within each of them:
• Fruits: apples, bananas, berries, oranges, melons, papaya, pears & peaches.
• Vegetables: asparagus, bell peppers, bok choy, broccoli, carrots, eggplant, leafy greens, okra, tomatoes & yams.
• Grains: amaranth, barley, buckwheat, oats, quinoa, rice & wheat.
• Legumes: chickpeas, lentils, beans & peas.
• Nuts: almonds, cashews, chestnuts, peanuts & walnuts.
• Seeds: chia, hemp seeds & flaxseeds.
• Healthy fats: avocados, olives & olive oil.
• Proteins: natto, nutritional yeast, tempeh, tofu, seitan, spirulina, eggs (in some varieties) & dairy products (in some varieties).
Vegetarian Diets & Health:
A vegetarian diet can have a positive impact on one’s health. Below are a few of the key benefits:
Dietary Sources of Vitamins & Minerals
Vegetarian diets are intended to be rich in various plant-based foods, which contain many vitamins & minerals that are healthful, including vitamins A, C, E, K & folate, & the minerals potassium, phosphorus, magnesium & manganese. These nutrients — some of which are not consumed in adequate amounts, are vital to the health of our eyes, immune system, muscles, heart, nerves, skin, gut, brain & more.
Heart Health Benefits
Vegetarian diets rich in fruits, vegetables & whole grains have been associated with heart health benefits. A systematic review & meta-analysis found that vegetarian diets lower blood concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, & non-high-density lipoprotein cholesterol. A meta-analysis found that a vegetarian diet was associated with lower blood pressure.
Decreased Cancer Risk
Some research has found that vegetarian diets are associated with a decreased risk of certain cancers,including colorectal & breast cancer.
Improved Blood Glucose Management
Several studies have examined diets high in plant-based foods & their impacts on diabetes-related risks. Compared to non-vegetarian diets, various types — including lacto, lacto-ovo & even semi-vegetarian — of vegetarian diets are associated with significantly lower levels of blood glucose & reduced insulin resistance, as well as a reduced risk of developing type 2 diabetes mellitus.
Pay Attention to These Nutrients:
There are a few nutrients that vegetarians should pay special attention to because they are primarily found in animal foods. These nutrients are mainly found in proteins like meat, poultry & fish & include omega-3 fatty acids as well as micronutrients like zinc, selenium, iron, iodine & vitamin B12. However, with careful attention & planning, it is possible to meet your nutrient needs on a vegetarian diet. Vegetarians should take care to incorporate a variety of nutritious choices, including fortified foods &/or dietary supplements when appropriate.
In Summary:
Due to its association with numerous health benefits, the vegetarian diet is one of the three healthy dietary patterns highlighted in the 2020-2025 Dietary Guidelines for Americans. While there are a few types of vegetarian diets, all emphasize plant-based foods like fruits, vegetables, whole grains & legumes. Although there are a few nutrients that vegetarian diets can be low in, with thoughtful preparation it is possible to receive the nutrients you need while adhering to this diet.
What is the Vegan Diet?
• Vegan diets only include plant-based foods.
• Research has shown that vegan or vegetarian diets rich in plant-based foods are associated with lower LDL cholesterol, improved blood glucose & improved blood pressure.
• There are a few nutrients that individuals following a vegan diet should be mindful to get enough of, including vitamin B12, calcium, iron & certain omega-3 fatty acids.
The Basics:
Vegan & vegetarian diets appear to be among the top food trends, but there is evidence that some people have been eating a predominantly plant-based or vegetarian diet for centuries. However, it wasn’t until 1944 that the term “vegan” was coined. Essentially, individuals who follow a vegan diet have opted to remove all animal-based foods from their diet. Many choose vegan clothing, household items & personal care items as well. Most individuals who adopt a vegan diet are doing so for the perceived health benefits or to advocate for animal rights.
What Foods Make Up a Vegan Diet?
Vegan diets are made up of only plant-based foods. This type of diet includes fruits, vegetables, soy, legumes, nuts & nut butters, plant-based dairy alternatives, sprouted or fermented plant foods & whole grains. Vegan diets don’t include animal foods like eggs, dairy, meat, poultry or seafood. They also are devoid of animal by products such as honey (made by bees) & lesser-known animal-based ingredients like whey, casein, lactose, egg white albumen, gelatine, carmine, shellac, animal-derived vitamin D3 & fish-derived omega-3 fatty acids.
Nutrients of Concern:
While the vegan diet can be very nutrient-rich, there are a few nutrients to be particularly aware of when adopting this style of eating: most notably vitamin B12, calcium, certain omega-3 fatty acids & iron.
Vitamin B12 is important for metabolism, heart, nerve & muscle health & it’s mostly found in animal products. Those following a vegan diet should opt for foods fortified with B12. Moreover, individuals following a vegan diet should communicate with a health care provider about monitoring their levels of B12 & their potential need for a supplement, keeping in mind that a deficiency in B12 could take years to manifest on a blood test.
Calcium is essential for dental, nerve, bone & muscle health & it is best absorbed with vitamin D. This nutrient is found predominantly in dairy foods & in lesser amounts in leafy greens like kale & broccoli. It is also found in fortified foods, such as tofu, bread & plant-based dairy alternatives. A systematic review found that individuals following a vegan or vegetarian diet had lower bone mineral density & higher fracture rates. Because calcium & vitamin D are key to bone health, those on a vegan diet are advised to talk to their healthcare provider to determine whether a supplement may be necessary.
Iron is a vital component of metabolism & heart health. It is found mostly in animal foods. Although fortified whole grains, beans, lentils, spinach & other plant-based foods provide iron, it’s in the form of non-heme iron, which is not as bioavailable as the heme iron found in animal foods.
Omega-3 fatty acids are a type of polyunsaturated fat shown to support cardiovascular health. The three most common types we eat are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) & docosahexaenoic acid (DHA). ALA is found in plant sources like flaxseed, chia seeds & walnuts, but EPA & DHA are found mainly in animal foods with the exception of some marine plant sources. ALA is converted by our bodies into EPA & DHA, but only in small quantities. Vegan options for EPA & DHA are microalgae & seaweed food products or supplements.
Lacto-ovo vegetarian:
A lacto-ovo-vegetarian diet includes eggs & dairy but avoids other animal products. Some research associates vegetarian diets with health benefits, such as reducing inflammation & lowering blood pressure.
What is a lacto-ovo-vegetarian diet?
excludes meat, poultry, & fish but includes eggs & dairy products. People commonly refer to this dietary pattern simply as a vegetarian diet.
The word “lacto” refers to milk, & “ovo” refers to eggs. Similarly, someone could choose to follow a lacto-vegetarian diet, excluding eggs but consuming milk.
People may follow a lacto-ovo-vegetarian diet for ethical reasons, such as animal rights or to help the environment. Other people choose the diet for health or religious reasons, or simply as a personal preference.
As farmers do not slaughter animals to obtain eggs, milk, & honey, many vegetarians choose to eat these foods. However, some people who follow a vegan diet may argue that the dairy & egg industries do involve slaughter or other animal cruelty & that producing honey exploits bees.
Health benefits:
A vegetarian diet that includes whole foods, fruits, & vegetables can help reduce a person’s risk of some chronic diseases. The following looks at what the evidence says about potential health benefits.
Foods to avoid:
People who eat a lacto-ovo-vegetarian diet avoid the following foods &
Ingredients:
meat & poultry
fish & seafood
insects or insect products, such as cochineal
gelatin & animal rennet
stock or fat from animals
Foods to eat:
A healthy lacto-ovo-vegetarian diet includes the following foods:
a wide variety of fruits & vegetables
eggs
dairy products, such as milk, cheese, & yogurt
tofu
beans & lentils
whole grains
healthy fats, such as olive oil, hemp oil, or avocado oil
nuts & seeds
Below are examples of what someone following a lacto-ovo-vegetarian diet could eat over a 5-day period.
Day 1
Breakfast: oatmeal with a sprinkling of chopped nuts & a drizzle of honey
Lunch: mixed salad with avocado, hummus, & oatcakes
Dinner: bean & vegetable chili with brown rice & steamed kale
Snacks: a piece of fruit or a boiled egg
Day 2
Breakfast: a boiled egg with a slice of whole grain toast spread with yeast extract
Lunch: feta cheese salad with greens, tomatoes, red pepper, & walnuts
Dinner: tofu stir fry with broccoli, cabbage, & carrots on buckwheat (soba) noodles
Snacks: peanut butter on oatcakes or a handful of nuts
Day 3
Breakfast: a smoothie containing whey protein, berries, spinach, & apple
Lunch: roasted vegetables & broad bean dip in a wholemeal wrap
Dinner: chickpea & butternut squash curry
Snacks: hummus & carrot or celery sticks or a piece of fruit
Day 4
Breakfast: sugar-free granola with Greek yogurt & berries
Lunch: pita bread filled with falafel, hummus, & salad greens
Dinner: vegetable & bean casserole with buckwheat dumplings & broccoli
Snacks: a piece of feta cheese or mashed avocado on a rice cake
Day 5
Breakfast: omelet with spinach & tomato
Lunch: cooked quinoa with steamed broccoli & toasted cashew nuts
Dinner: bean chili with sweet potato wedges & low fat sour cream
Snacks: sugar-free trail mix or a chocolate protein ball
Summary:
A lacto-ovo-vegetarian diet, which people usually refer to as a vegetarian diet, can be a healthy way to eat.
There are plenty of options for protein, including eggs & dairy products. Someone eating a varied diet usually does not need to worry about getting enough amino acids.
Research has associated vegetarian diets with health benefits, including lower blood pressure & a lower risk of diabetes & cardiovascular disease.
Certain groups of people eating a vegetarian diet should work with a registered dietitian to ensure that they get enough nutrients. Generally, people should eat mainly whole foods & avoid processed foods to stay healthy.
What is a Pescatarian Diet?
The pescatarian diet is neither fully nor semi vegetarian. A vegetarian avoids eating all animal meats:
• Red meat – meat from livestock animals such as cows, pigs, & lambs.
• Poultry (also called white meat) – meat from birds such as chickens, turkeys, & ducks.
• Seafood – meat from aquatic life such as all fish, crustaceans (e.g., lobster & crab) & molluscs (e.g., scallops & mussels).
A pescatarian, on the other h&, is someone who eats a vegetarian diet with the addition of fish & other seafood but no other types of meat. In fact, this is the only prerequisite for pescatarians, & in this way the diet is quite simple to grasp.
As a pescatarian, exactly how much fish you eat is completely down to you – there is no limitation. Many pescatarians also eat non-meat animal products – i.e. eggs & dairy products – while others choose not to.
What do pescatarians eat?
Pescatarians can consume all products containing types of fish & other seafood, including:
Salmon. | Prawns |
Tuna. | Cod. |
Scallops | Crab. |
Lobster | Squid. |
For a balanced diet, they should also eat a range of vegetarian foods, including:
Fruit & vegetables. | Whole grains & cereals (such as rice, bulgur wheat, & oats). |
Legumes (such as all types of beans & peas). | Nuts & seeds (such as flaxseeds & chia seeds |
Eggs & dairy, if lacto-ovo-vegetarian (such as eggs, cheese, & milk |
|
Why do people become pescatarian?
There are many possible reasons for becoming a pescatarian. Here are some of the most common:
• Ethical motivations – some people are against killing animals for food. While fish are also living creatures, transitioning from an omnivore (meat & plant-based) diet to a pescatarian diet is more manageable for some meat lovers & still limits animal consumption. What’s more, the conditions in which many l& animals (livestock) are raised for slaughter are often seen as poor & inhumane.
• Environmental concerns – Raising livestock also comes with an environmental cost – the practice is responsible for 15% of all man-made carbon emissions2, making a sizeable contribution to the global warming crisis. In comparison, people who eat fish are thought to cause around 46% fewer greenhouse gas emissions than those who eat at least one serving of other meat a day.
• Health benefits – limiting your meat intake is associated with a lower risk of several health issues, including obesity, type 2 diabetes, & heart disease.
Is the pescatarian diet healthy?
“A pescatarian diet typically includes lots of lean protein in the form of white fish, & plenty of omega-3 fatty acids from oily fish such as salmon, mackerel, fresh tuna, & sardines.”
• Omega-3 fatty acids – ‘healthy fats’ that help keep your heart, blood vessels, lungs, & immune system healthy.
• Protein – a nutrient needed for many important functions, including the growth & repair of cells, muscle health, bone health, hormone regulation, & digestive health.
• Many types of fish are a good source of omega-3 fatty acids & lean protein.
“Coupled with whole-grain cereals, nuts, fruit, vegetables & small amounts of dairy, this forms the basis of the Mediterranean diet which is widely recognized as one of the healthiest lifestyle diets.”
What is a Flexitarian Diet?
The Basics:
Most people do not consume the recommended amounts of dairy, fruits, legumes (e.g., chickpeas, lentils & beans, including soy), seafood, vegetables or whole grains.1,2,3 While a complete diet overhaul may seem daunting, one style of eating—the “flexitarian diet”—attempts to make it easier to shift dietary choices by focusing more on what can be added to the diet rather than what should be taken away.
• The flexitarian diet can be generally defined as a semi-vegetarian, plant-forward diet.
• More specifically, the flexitarian diet is a flexible eating style that emphasizes the addition of plant or plant-based foods & beverages, incorporates dairy & eggs & encourages meat to be consumed less frequently &/or in smaller portions.
• There are no set calorie or macronutrient goals in a flexitarian diet.
• The principles of the flexitarian diet align with recommendations in the 2020–2025 Dietary Guidelines for Americans.
• Emerging evidence suggests that the flexitarian diet may help reduce the risk of cardiovascular disease, diabetes & certain types of cancer, as well as assist with weight management.
The flexitarian diet is a play on two words: flexible & vegetarian. While no single definition has been adopted, the flexitarian diet can be generally defined as a semi-vegetarian, plant-forward diet that incorporates dairy & eggs & allows room for meat from time to time. The emphasis on plant foods is thought to contribute to the health benefits associated with a vegetarian diet without requiring compliance to the dietary rules of 100%-vegetarian or vegan diets.
There are no set calorie or macronutrient goals in a flexitarian diet. Instead, the goal is to increase the consumption of plant or plant-based foods over time, keeping in mind that meat is not off-limits but rather that it is eaten less frequently &/or in smaller portions.
Calories in the flexitarian diet mostly come from nutrient-rich foods such as fruits, legumes, whole grains & vegetables. When it comes to protein, plant-based foods (e.g., soy foods, legumes, nuts & seeds) are the primary source. Protein also comes from eggs & dairy, with lesser amounts coming from meat, especially red & processed meats. Due to the emphasis on nutrient-dense foods, the flexitarian diet encourages limiting one’s intake of saturated fat, added sugars & sodium.
The Flexitarian Diet & Your Health:
A flexitarian diet can have a positive impact on health,4,5 while being less strict than a 100%-vegetarian or vegan diet. The plant-forward philosophy of a flexitarian diet aligns with the 2020–2025 Dietary Guidelines for Americans which recommend choosing more nutrient-dense foods (fruits, vegetables, legumes, whole grains, low-fat dairy, lean proteins & healthy fats) & beverages & relatively less red & processed meats, sugar-sweetened foods & beverages, & refined grains.3
The protective effects of the foods emphasized in the flexitarian diet are thought to be due to multiple beneficial nutrients contained in these foods, including mono- & polyunsaturated fatty acids, omega-3 fatty acids, antioxidant vitamins, minerals, phytochemicals, fibre & protein.
There is a growing body of evidence examining the health effects associated with adopting a flexitarian diet, including implications for heart disease, diabetes, cancer & weight management.
Tips for Trying a Flexitarian Diet:
• At each meal, build a plate with fruits, vegetables, whole grains, legumes & healthy fats.
• When choosing protein sources, opt for plant-based foods (e.g., soy foods, legumes, nuts & seeds), dairy & eggs most of the time.
• Take advantage of the flexibility of this plan—meat can be incorporated from time to time, but be mindful of its portion sizes.
• Include more whole, nutrient-dense foods, which may naturally reduce the consumption of foods or beverages that are high in calories, saturated fat, added sugars & salt.
In Summary:
At its core, the flexitarian diet allows for flexibility, which may be appealing to some who are looking for a path to improved health that has fewer rigid rules. The main purpose of this diet is to slowly increase one’s plant intake over time without omitting animal foods. With its emphasis on plant & plant-based foods, the flexitarian diet is comprised of beneficial vitamin-, mineral-, & fibre-containing foods & has been associated with a reduced risk of type 2 diabetes, cardiovascular disease & cancer.
We are embracing plant based diets more so than ever before. Three primary reasons may be the influencing factor behind this dietary shift.
1. Health concerns as our population ages
2. Environmental & Climate change issues
3. Animal welfare concerns
As discussed above, raising livestock comes at a high environmental cost in regard to carbon emissions & the global warming crisis, secondly, plant based substitutes that mirror both the appearance & taste of meat offering genuine health benefits are now readily available in supermarkets.
Some key nutrients to consider on plant-based diets: Protein:
Protein is a macronutrient made up of various amino acids. Nine of these are referred to as ‘essential’ amino acids, because we cannot make them & need to source them from our diet. Amino acids are the building blocks not only of muscle, but also of hormones, immune cells & even neurotransmitters. Consuming a good variety of plant proteins is important to ensure you’re getting all essential amino acids. Some high-quality plant-based proteins include:
• Vegetarian meat substitutes like quorn (a fermented mycoprotein) or seitan (made from wheat gluten)
• Nuts & seeds, nut butters or cashew ‘cheese’
• Plant based (e.g. hemp or pea) protein powder
• It may surprise you to learn that grains like quinoa & teff provide valuable protein too
• soybean products like soy milk, tofu & tempeh
• legumes (beans, chickpeas, lentils)
Iron:
Iron is important for oxygen transport & immune function. A deficient diet can result in anaemia, with symptoms like fatigue, listlessness, poor immune function, muscle aches & headaches. As you can imagine, an iron deficient vegan is not going to be much fun to hang out with!
Iron is found in two main forms – haem iron (found in meat, seafood, chicken, organ meats) & non-haem iron (found in plant foods, eggs & dairy). Vegetarian or vegan diets only provide non-haem iron, which is more difficult for us to absorb than haem iron. To boost your iron intake from food:
- Include legumes, tofu, tempeh, nuts & seeds regularly
- Look for iron-fortified foods (e.g. breads, cereals, plant milks)
- Eat plenty of green leafy vegetables (e.g. spinach, kale, rocket, broccoli)
- Include a range of wholegrains (e.g. quinoa, amaranth, brown rice, rolled oats)
& some tips to enhance your iron absorption
- Vitamin C increases absorption of iron, so include vitamin C- rich foods with meals (e.g. citrus, strawberries, kiwi fruit, tomatoes, capsicum)
- Avoid drinking tea & coffee with meals (tannins can inhibit iron absorption)
Avoid taking calcium supplements with meals (these can reduce iron absorption)
Calcium:
Studies indicate that vegans tend to have lower bone density & higher fraction risk than non-vegans, so getting enough of this essential bone-building mineral is a key consideration for those choosing a healthy plant-based diet.
The highest calcium-containing foods in our diet are dairy products (milk, yoghurt & cheese), so lacto-ovo vegetarians consuming 2-4 serves of dairy foods daily will be well covered. When switching to plant-based alternatives, ensure your milk is fortified with calcium (at least 100mg per 100mL).
It’s also important to understand that many plant-based yoghurts & cheeses are based on highly saturated oils (e.g. coconut, palm), & don’t provide the calcium & protein we would get from traditional dairy products.
Other reasonable plant-based calcium sources include:
• Tofu set with included calcium (which will be listed under ingredients as e516)
• Tahini, chia seeds, kale, chickpeas, figs, baked beans & dried figs
Iodine:
Although a lesser talked-about micronutrient, iodine is an essential part of our diet. The most significant sources in the Australian diet include seafood, iodised table salt & fortified breads. Too little iodine can cause an enlarged thyroid gland (goitre), hypothyroidism & can also affect fertility, pregnancy & children’s development.
• Rather than sea salt, use iodised table salt in cooking
• Include sea vegetables like seaweed (e.g. nori) regularly if you don’t eat seafood