In ancient times, humans adopted a diet light on meat and heavy on plant-based foods, for varying reasons. For instance, the Greek philosopher, Pythagoras — the man who coined the Pythagorean Theorem — heralded a diet free of flesh as a way to minimize the bloodshed of living creatures. But modern humans have trended away from the “ancient diets,” instead turning to the high-fat, low-fiber Western diet that has contributed to the increased incidence of chronic diseases such as obesity, type 2 diabetes (T2D) and cancer. This worsening metabolic disease trend has inspired movements founded on returning to our “plant-based roots.” In this article, we explore a plant-based diet for beginners, the myriad health benefits of plant-based diets and provide you with an easy-to-adopt guide to adopting one, together with tips on overcoming common challenges.
What is a plant-based diet?
“Plant-based diet” is a term first coined by Thomas Colin Campbell, a biochemist at Cornell University, as he surveyed rural Chinese rural populations over a period of 20 years. There, he noted the high prevalence of diets low in fat and high in dietary fiber and other plant material: essentially, the exact opposite of the modern Western diet. A plant-based diet can take many forms, and contrary to popular opinion, doesn’t mean you have to eliminate meat — just eat less of it. Remember, all vegetarian diets are plant-based, but not all plant-based diets are vegetarian. The most common plant-based diets are:
- Vegetarian: Vegetarians exclude the eating of any food derived from flesh. This includes poultry, meat and fish.
- Vegan: Vegans take the vegetarian diet one step further. Their diet excludes all dairy, eggs and any other ingredients derived from animals.
- Pescatarian: People adopting this diet do not eat poultry and meat, but will consume fish in their diet. The term combines the Italian word for fish (pesce) with the final syllables of the word vegetarian.
Of course, there are several other variations of plant-based diets, but the important thing to note about all of them — whether they exclude meat or not — is the emphasis on whole foods derived from plants.
What are the benefits of a plant-based diet
Thomas Campbell noted in his 2005 book, The China Study, that those who ate a plant-based diet appeared at lower risk for the development of several diseases. Hundreds of research studies have since confirmed his observations:
- Cardiovascular disease (CVD): A 2022 randomized crossover trial of 62 overweight adults determined that those who ate a plant-based diet (Mediterranean or vegan) had improved weight loss, reduced blood cholesterol levels and reduced blood pressure. A 2019 meta-analysis of nine trials comprising 664 participants further showed that people who ate a vegetarian diet had lower fasting glucose levels, reduced cholesterol concentrations and improved body weight and BMI scores. These improvements may explain in part the reduced risk of CVD and ischemic heart disease mortality among vegetarians relative to people adopting other diets. The robustness of the data has led to recommendations for adopting a plant-based diet to reduce the risk of atherosclerosis.
- Obesity and type 2 diabetes (T2D): A 2015 systematic review and meta-analysis of 15 trials demonstrated that people who adopted a vegetarian diet were more likely to experience greater weight loss, which is a key requirement for individuals with T2D. This weight loss was further increased among people with a higher starting weight. A 2022 study monitoring blood determined that people who ate a plant-based diet produced higher levels of plant-associated metabolites that correlated with reduced T2D risk.
- Bone Health: A plant-based diet provides a host of nutrients including magnesium, potassium, vitamin K, vitamin C and zinc. Each of these compounds plays an important role in maintaining bone health. For instance, vitamin C deficiency leads to scurvy, a condition that causes extreme bone pain. Furthermore, a 2019 meta-analysis of 13 studies showed that at least one serving of fruits and vegetables a day reduces the risk of bone fractures.
- Cancers: A 2016 meta-analysis of 29 studies determined that eating more nuts reduced the risk of cancer overall, as well as all-cause mortality. Regarding vegan or vegetarian diets, the benefits seem to be more nuanced. On the one hand, a 2015 study determined that following a vegetarian diet did not significantly reduce the risk of colorectal cancer compared with non-vegetarian diets. On the other hand, a 2014 study done on British participants showed that the risk of getting cancer as a whole was lower among fish eaters and vegetarians compared with meat eaters. These mixed results observed across cancer studies could have stemmed from differences in sample size and diet group categories implemented in the studies.
- COVID-19: While lifestyle choices that maximize respiratory health are vital, adopting a healthy plant-based diet may also decrease the risk of severe COVID-19 and mortality from this disease.
Plant-based diet for beginners: Getting started
With all the benefits of adopting a plant-based diet for your health, what’s the best way to get started on a plant-based diet for beginners? The first step is recognizing that you will need to eat foods belonging to each of four main food groups.
- Fruits: Fruits are seed-bearing structures found in flowering plants. Fruits can be grouped by their seed dispersal method, their shape, and even their outer layer, or pericarp. All fruits are rich in many essential nutrients, including antioxidants such as vitamin C and ions such as zinc and magnesium. Note: It is more nutritious to eat a wide variety of of fruits to benefit from the different compounds in each, rather than focusing on high consumption of any one fruit.
- Vegetables: Vegetables comprise any plant part consumed for food that is not a fruit or a seed. Like fruits, the vegetable group comprises a huge list of diverse plants. A 2018 biodiversity survey determined that there were at least 1097 known vegetables in the world. With their substantial diversity, vegetables provide a myriad of nutrients, including potassium, dietary fiber, folate, vitamin A, and vitamin C. Like fruits, different kinds of vegetables provide unique health benefits due to the variety of distinct compounds found in different plants. For instance, cruciferous vegetables contain a potent antioxidant called sulforaphane that can aid the fight against cancer and even COVID-19.
- Whole Grains: Grains typically comprise three components: the germ, endosperm and bran. The bran and germ layers act as the outer layer and seed core of the grain, respectively. The bran and germ layers provide the bulk of nutrients that whole wheat possesses. The bran layer is rich in nutrients and phytochemicals that provide antioxidant and anticancer properties, while the seed core is rich in healthy fats, vitamin E, vitamin B and other antioxidants. Also of importance, the germ layer provides the bulk of fiber in whole grains, a key feature in a plant-based diet. Whole wheat foods are excellent choices for obtaining the grains you need in a plant-based diet.
- Legumes: Legumes are a subset of vegetables whose plants produce pods with seeds inside. These vegetables include beans, peas and lentils. Legumes provide a wide range of nutrients. Legumes are rich in fiber, protein, carbohydrates, vitamin B, iron, copper, magnesium, manganese, zinc and phosphorus. If eating less meat is part of your goal, then legumes provide a good alternative protein source.
Fun ways to move towards a plant-based diet for beginners
With so much diversity of foods to choose from, a plant-based diet for beginners will help you take your first steps towards a diverse diet and a healthier life. On that note, here are some fun ideas to implement so you can start your journey towards a plant-based diet:
- Meatless Mondays: Unless you’re adopting a vegan or vegetarian diet, you don’t have to ditch your meats to introduce the plant-based diet in your life. Pick a day of the week when your meals will only be derived from plants. Use legumes as your protein source and consider using nuts or oat milks as your source of dairy.
- Find creative menu ideas: There are many great online resources when it comes to finding recipes for a plant-based diet. Consider making a healthy pizza, being sure to leave out the meats, or a plant-based smoothie. Or, consider these additional recipes.
- Be careful with processed foods: Not all plant-based foods are equally healthy. Note that processed plant-based foods do exist, and these foods can increase the risk of acquiring chronic diseases. Be sure to check the nutrition labels for additives such as the ones listed here. A general rule of thumb is to shop the perimeter of your grocery store, where most fresh fruits and vegetables are found; on the perimeter, the aisles are often full of processed foods.
Are there nutrients you might be missing with a plant-based diet?
The biggest drawback in adopting a plant-based diet lies in the absence of certain important nutrients that one can only get from animal sources. There are ways to mitigate these deficiencies, but they can still be a challenge if you adopt a strict plant-based diet.
- Vitamin B12: Also known as cobalamin, this vitamin is essential for our bodies to produce healthy red blood cells, maintain a strong central nervous system and synthesize DNA for your cells. Vegans are more likely than vegetarians and omnivores to be deficient in vitamin B12 while having higher folate concentrations, as observed in a 2010 cross-sectional study. Finding plant-based foods fortified with vitamin B12 or obtaining a vitamin B12 supplement are the best ways to obtain this essential vitamin if you go completely meat-free.
- Vitamin D: A deficiency in this vitamin is a notable problem for those who adopt a plant-based diet. Vegans and vegetarians are more susceptible to vitamin D deficiency, highlighting the challenge of obtaining enough vitamin D from a plant-based diet. Those who adopt a plant-based diet would do best obtaining vitamin D either from fortified grains and plant-based milk sources, basking in more sunshine, or obtaining vitamin D supplements. But never take an excessive amount — greater than the recommended daily amount, or RDA — of any vitamin or supplement. See our report, Vitamins and Minerals: Can You Take Too Many?
- Omega-3s: These polyunsaturated fatty acids play critical roles in gut health and proper brain function and they help reduce the risks for multiple metabolic diseases. The challenge in obtaining enough Omega-3s for people adopting a plant-based diet lies in the fact that Omega-3s are derived from fish-based sources. There are some plant-based foods rich in Omega-3s, such as algae, edamame and Brussels sprouts. Omega-3 supplements can be taken if eating those vegetables is not sufficient; make sure that the Omega-3 supplement contains both eicosapentaenoic acid and docosahexaenoic acid.
What if you have a contraindication?
In addition to the challenge of obtaining sufficient quantities of certain vitamins, some people may have contraindications that make eating a plant-based diet more difficult. Even in these situations, there are still ways to get around the problem:
- Type 2 diabetes: Because of their high carbohydrate content, fruits in large quantities can be contraindicated for individuals with T2D. Nevertheless, there are specific kinds of fruits that provide important nutrients without overloading on the carbs. Some of the best fruits include berries, grapes, oranges, plums, peaches and pears due to their associated lower risk of T2D.
- Celiac disease: If your immune system damages your own small intestine after eating foods containing gluten, you may have celiac disease. Plant-based foods containing wheat, rye, and barley contain gluten — and patients with celiac disease must avoid these foods. Nevertheless, such individuals can still eat other kinds of grains. Rice, corn, flax, millet, oats and buckwheat are excellent grain alternatives free of gluten. There are also recipes for preparing gluten-free bread. See our report, Is Gluten Bad For You?
- Pregnancy: A plant-based diet can be a challenge for pregnant women because they need additional nutrients both for their own health and for the sake of the growing fetus. Ensuring an adequate supply of proteins, iron, folic acid, calcium and other nutrients is essential during pregnancy. Having a hearty supply of beans, broccoli and leafy greens can help meet some of the additional nutritional requirements. If necessary, there are many ways to use supplementation to obtain the nutrients pregnant women need if they can’t obtain enough from those dietary sources.
Modern Western society has moved away from a plant-based diet to one that is high-fat (read: high-calorie) and low in nutritional content. Plant-based diets for beginners provide a wide range of benefits that contribute to health and longevity. In particular, adopting a plant-based diet can help reduce the risk of acquiring chronic diseases such as CVD, T2D and cancer. With so many plant-based foods to choose from, there are many creative, delicious ways to get started on your journey toward a plant-based diet for beginners. While nutrient deficiencies can be an issue when adopting a strict plant-based diet, an adequate nutrient supply can be obtained through supplementation or by focusing on eating fortified plant-based foods. You don’t have to stop adopting a plant-based diet if you have a contraindication, either, unless your physician advises otherwise. And remember, eating a plant-based diet for beginners doesn’t mean you have to give up meat completely; just try to eat far less of it!