Plant-based eating patterns are gaining popularity due to increased awareness of their potential health and environmental benefits. But what exactly does "plant-based diet" mean? Is it the same as being vegetarian or vegan? Or does this diet just mean you make an effort to pack more veggies into your meals? Technically, all of the above interpretations are correct. Some people use the term ‘plant-based diet’ as a synonym for the vegan diet. Others may use the term in a broader way that includes all vegetarian diets, and I’ve also seen people use ‘plant-based’ to mean diets that are composed mostly, but not entirely, of plant foods.
This article explores the benefits and potential risks of plant-based diets, providing a structured overview to help you understand and implement this eating pattern effectively.
What is a Plant-Based Diet?
Plant-based or plant-forward eating patterns focus on foods primarily from plants. This includes not only fruits and vegetables, but also nuts, seeds, oils, whole grains, legumes, and beans. It doesn't mean that you are vegetarian or vegan and never eat meat or dairy. The idea of a plant-based diet is to make plant-based foods the central part of your meals.
A plant-based diet emphasizes foods like fruits, vegetables, and beans, and limits foods like meats, dairy, and eggs. From there, more restrictions could be put in place depending on how strict you want to be. It may completely eliminate foods from animals or just limit intake, depending on the individual’s interpretation. That means meat and seafood don’t necessarily need to be off-limits - you might just decide to cut down on how frequently you eat those items.
Evidence Supporting Plant-Based Diets
Much nutrition research has examined plant-based eating patterns such as the Mediterranean diet and a vegetarian diet. Plant-based diets offer all the necessary protein, fats, carbohydrates, vitamins, and minerals for optimal health, and are often higher in fiber and phytonutrients.
Read also: Foods and Fibroids
Key Components of a Plant-Based Diet
- Eat lots of vegetables: Fill half your plate with vegetables at lunch and dinner. Make sure you include plenty of colors in choosing your vegetables.
- Change the way you think about meat: Have smaller amounts.
- Choose good fats.
- Cook a vegetarian meal at least one night a week.
- Include whole grains for breakfast: Start with oatmeal, quinoa, buckwheat, or barley.
- Go for greens: Try a variety of green leafy vegetables such as kale, collards, Swiss chard, spinach, and other greens each day.
- Build a meal around a salad: Fill a bowl with salad greens such as romaine, spinach, Bibb, or red leafy greens.
- Eat fruit for dessert.
Over time, eating a plant-based diet will become second nature.
Benefits of Plant-Based Diets
A well-planned plant-based diet can be safe for everyone, including babies, children, and women who are pregnant or nursing, notes the Academy of Nutrition and Dietetics. As the following research suggests, a plant-based diet may help reduce the likelihood that you’ll need medication, and also lower your risk of obesity and high blood pressure.
There are several health benefits to following a plant-based diet. Here are some of them:
- Reduced risk of type 2 diabetes: In one review, researchers found that following a plant-based diet was associated with a lower risk of type 2 diabetes.
- Healthier weight and blood sugar level in people with diabetes: A plant-based diet may be beneficial for boosting metabolism, managing weight, and reducing inflammation, especially among people with obesity and those with type 1 and type 2 diabetes.
- Reduced risk of heart disease: Studies have linked following a diet rich in plant foods and lower in animal foods to a 16 percent lower risk of cardiovascular disease and 31 to 32 percent lower risk of death from cardiovascular disease.
- Reduced risk of cancer: One study showed that people who ate low quantities of meat and fish had a lower risk of colorectal, breast, and prostate cancer compared to study participants who ate larger amounts of meat and fish. Another study focused on breast cancer specifically and found that individuals who most closely followed a plant-based diet had 67 percent lower risk of breast cancer than those who followed it the least.
- Healthier brain: While research is mixed, one study involving more than 3,000 adults found that sticking with a plant-based diet was linked with better cognitive function, including long-term memory and executive function, though future research should explore the mechanisms behind why this happens.
- Longer life: Some research links a diet containing higher levels of plant protein with a lower rate of early death from all causes. One study of 135,000 individuals found a link between increased intake of fruits, vegetables, and legumes and a lower risk of all-cause early death, with participants reaping maximum health benefits at three to four servings per day - an amount that anyone following a plant-based diet is likely to meet.
Research shows that plant-based diets are cost-effective, low-risk interventions that may lower body mass index, blood pressure, HbA1C, and cholesterol levels. They may also reduce the number of medications needed to treat chronic diseases and lower ischemic heart disease mortality rates.
Case Study Example
A 63-year-old man with a history of hypertension presented to his primary care physician with complaints of fatigue, nausea, and muscle cramps. The result of a random blood glucose test was 524 mg/dL, and HbA1C was 11.1%. Type 2 diabetes was diagnosed. His total cholesterol was 283 mg/dL, blood pressure was 132/66 mmHg, and body mass index (BMI) was 25 kg/m2. He was taking lisinopril, 40 mg daily; hydrochlorothiazide, 50 mg daily; amlodipine, 5 mg daily; and atorvastatin, 20 mg daily. He was prescribed metformin, 1000 mg twice daily; glipizide, 5 mg daily; and 10 units of neutral protamine Hagedom insulin at bedtime. His physician also prescribed a low-sodium, plant-based diet that excluded all animal products and refined sugars and limited bread, rice, potatoes, and tortillas to a single daily serving. He was advised to consume unlimited non-starchy vegetables, legumes, and beans, in addition to up to 2 ounces of nuts and seeds daily.
Read also: Diet Plan for Picky Eaters
The patient was seen monthly in his primary care clinic. Over a 16-week period, significant improvement in biometric outcome measures was observed. He was completely weaned off of amlodipine, hydrochlorothiazide, glipizide, and neutral protamine Hagedorn insulin. Follow-up blood pressure remained below 125/60 mmHg, HbA1C improved to 6.3%, and total cholesterol improved to 138 mg/dL.
This case is a dramatic example of the effect a plant-based diet can have on biometric outcomes like blood pressure, diabetes, and lipid profile. The reduction in HbA1C from 11.1% to 6.3% in 3 months is much better than would be expected with monotherapy with metformin or daily exercise. The improvement in blood pressure observed over a 4-month period with few medications is also rarely encountered in clinical practice and is likely related to a low-sodium diet and the avoidance of red meat.
Potential Risks and Considerations
While there are many health benefits to a plant-based diet, there are some challenges as well.
- Not all ‘plant-foods’ are created equal: Simply sticking with plant-based foods likely isn’t going to cut it. There are plenty of unhealthy foods that qualify as plant-based, such as potato chips and french fries. Unhealthy processed plant-based foods will increase your risk of weight gain and health conditions such as heart disease.
- Bowel movements: When you first switch to a plant-based diet, you may notice an uptick in bowel movements, diarrhea, or constipation. That’s because many plant-based foods are a good source of fiber, and fiber normalizes bowel movements. Consider gradually incorporating plant-based foods in your diet to give your body time to adjust, and be sure to drink plenty of fluids while you’re making the switch to eating more plants and afterward.
- Lack of B12 and choline: While many plant-based foods are loaded with nutrients, there are some that are harder to come by if you completely eliminate animal food products from your diet. You may need to keep an eye on your levels of vitamin B12 and choline. Vitamin B12 is found primarily in animal sources, and the two best sources of choline are egg yolks and liver. If a person is avoiding animal products, they may not be taking in enough of these nutrients. Nutritional yeast is a great source of B12 that’s easy to add to many plant-based meals. Legumes, soy, and peanuts are a great source of plant-based choline.
- Protein Deficiency: Generally, patients on a plant-based diet are not at risk for protein deficiency. Proteins are made up of amino acids, some of which, called essential amino acids, cannot be synthesized by the body and must be obtained from food. Essential amino acids are found in meat, dairy products, and eggs, as well as many plant-based foods, such as quinoa. Essential amino acids can also be obtained by eating certain combinations of plant-based foods. Examples include brown rice with beans, and hummus with whole wheat pita.
- Iron Intake: Plant-based diets contain iron, but the iron in plants has a lower bioavailability than the iron in meat. Plant-based foods that are rich in iron include kidney beans, black beans, soybeans, spinach, raisins, cashews, oatmeal, cabbage, and tomato juice. Iron stores may be lower in individuals who follow a plant-based diet and consume little or no animal products.
- Vitamin B12 Deficiency: Vitamin B12 is needed for blood formation and cell division. Vitamin B12 deficiency is a very serious problem and can lead to macrocytic anemia and irreversible nerve damage. Vitamin B12 is produced by bacteria, not plants or animals.
- Calcium Intake: Calcium intake can be adequate in a well-balanced, carefully planned, plant-based diet. People who do not eat plants that contain high amounts of calcium may be at risk for impaired bone mineralization and fractures. However, studies have shown that fracture risk was similar for vegetarians and nonvegetarians. The key to bone health is adequate calcium intake, which appears to be irrespective of dietary preferences. Some significant sources of calcium include tofu, mustard and turnip greens, bok choy, and kale.
- Vitamin D Deficiency: Vitamin D deficiency is common in the general population.
- Essential Fatty Acids Deficiency: The fatty acids that vegans are most likely to be deficient in are the omega-3 fats (n-3 fats). Consumptions of the plant version of omega-3 fats, alpha-linolenic acid, are also low in vegans. Adequate intake of n-3 fats is associated with a reduced incidence of heart disease and stroke. Foods that are good sources of n-3 fats should be emphasized.
- Concerns over the estrogenic nature of soy products: Because of concerns over the estrogenic nature of soy products, women with a history of breast cancer should discuss soy foods with their oncologists.
- Patients with kidney disease: Patients with kidney disease may need a plant-based diet with special restrictions, for example fruits and vegetables that are high in potassium and phosphorus.
- Patients with thyroid disease: Finally, patients with thyroid disease will need to be careful when consuming plants that are mild goitrogens, like soy, raw cruciferous vegetables, sweet potatoes, and corn.
Cost of a Plant-Based Diet
You may have heard people complaining that plant-based products are more expensive than their omnivorous diet counterparts. Generally speaking, this is true. Oat milk or almond milk tend to be pricier than cow’s milk, and you may pay a slight premium for vegan cheese over dairy cheeses as well. On the other hand, plant-based protein sources tend to cost significantly less than meat or fish protein.
One study actually looked into the overall cost of a plant-based diet and asked this question: Do people following a plant-based diet pay more for food? The researchers concluded that overall, people following a plant-based diet actually pay less for food. Researchers do note that this study relied on the honesty of participants, rather than actually recording the specific costs of food, and they outline the need for further studies with less subjective research methods.
Read also: Vegan Diet for Diabetes Management
Foods to Include and Avoid
Earlier we discussed how “plant-based diet” can mean a diet that is primarily plant-based, but some people do sneak in some animal foods as well, provided that the diet is mostly plant-based. For the purposes of these lists, we will take a plant-foods-only approach.
Top 10 Foods to Eat
- Leafy green vegetables (including spinach, Swiss chard, collard greens)
- Cruciferous vegetables (including broccoli, kale, cabbage, cauliflower)
- Root vegetables (including carrots and sweet potatoes)
- Fruits (such as avocados, strawberries, blueberries, watermelon, apples, grapes, bananas, grapefruit, and oranges)
- Whole grains (such as quinoa, farro, brown rice, whole-wheat bread, and whole-wheat pasta)
- Nuts (walnuts, almonds, macadamia nuts, and cashews all count)
- Seeds (such as flaxseed, chia seeds, and hemp seeds)
- Legumes (beans, lentils, chickpeas)
- Soy (tofu, soy milk, tempeh)
- Plant-based probiotics (like kimchi or kraut)
Top 10 Foods to Avoid
- Dairy (including milk and cheese)
- Meat and poultry (like chicken, beef, and pork)
- Processed animal meats, such as sausages and hot dogs
- Fish
- Other processed foods (like potato chips, chocolate bars)
- Eggs
- Refined grains (such as “white” foods, like white pasta, rice, and bread)
- Sweets (like cookies, brownies, and cake)
- Sweetened beverages, such as soda, and fruit juice
- Fried foods
Getting Started: Tips for Beginners
Feeling overwhelmed because plant-based eating is a complete 180 from your current diet? Don’t overthink it. Here are five tips on making the transition. Bonus: Research has shown that plant-based diets are, by comparison, more affordable than those that include meat.
- Think Outside the Produce Aisle: Stock up on grains, canned beans, and canned or frozen fruits and veggies so you don’t have to shop every few days.
- Swap Meat for High-Protein Legumes: Tofu, tempeh, black beans, chickpeas, pinto beans, and dried peas are some of your many options.
- When Eating Out, Ask the Waiter for Suggestions: Sometimes a server will help you piece together a meal with sides and appetizers if there isn’t a plant-based main course on the menu.
- Choose Budget-Friendly Options: Keep grocery costs down by buying in-season produce and sticking to simple plant-based foods such as grains, beans, and frozen and canned foods.
- Keep Nutrition Basics in Mind: Limit the sugar, fat, and refined grains you cook with at home. These ingredients can quickly make a home-cooked plant-based meal unhealthy.
The GreySheet Diet
Up until 1986, Overeaters Anonymous - a 12-step program geared toward people struggling with eating disorders such as binge eating and food addiction - distributed food plans to its members on grey-colored paper, creating what came to be known as the GreySheet diet. Overeaters Anonymous no longer endorses the GreySheet diet. But other organizations, including GreySheeters Anonymous, continue to encourage new members to follow the program through sponsors - members who have stuck to the diet for at least 90 days. The GreySheet diet may not be a healthy choice for everyone. So, talk with your doctor before you try it.
How the GreySheet Diet Claims to Work
While GreySheeters Anonymous endorses the dietary plan, the group does not believe that you should tackle it on your own. Instead, it recommends that you work with a sponsor. In fact, you cannot get a copy of the meal plan without finding a sponsor first. The basic plan emphasizes eating foods that are high in protein and low in carbohydrates. The diet requires eliminating all sugar and sugary desserts (such as cake or candy), alcoholic drinks, and grain products such as bread, cereal, and noodles. The diet does not allow for snacks between breakfast and lunch, or between lunch and dinner. The only things permitted between meals include diet soda, tea, and black coffee. The plan does recommend vitamin supplements, especially ones containing calcium, vitamin E, and the B vitamins.
Effectiveness of the GreySheet Diet
It’s hard to say how effective the GreySheet diet is. The majority of positive reviews come from anecdotal evidence, or people who say they found success following the dietary plan. There is scant scientific research to support its effectiveness. The diet involves eating three meals a day with no snacks. That may work for some. But lifestyle changes for binge eating disorder - one of the conditions GreySheeters Anonymous suggests it helps with - often include eating every two to three hours and avoiding diets.
What Can You Eat on the GreySheet Diet?
A typical day on the original GreySheet diet involves weighing and measuring the amount of food you eat at each meal. The original plan notes that calorie intake per day is less than 2,000 calories. Here’s an example of a daily plan:
- Breakfast: A serving of protein and a serving of fruit. This might be two boiled eggs or 1 cup of plain, unsweetened yogurt, and 1 cup of strawberries.
- Lunch: One serving of protein and one serving of a vegetable, along with a small salad consisting of salad greens with no dressing or three raw vegetables. Four ounces (oz) of grilled chicken, 1 cup of cooked broccoli, and romaine lettuce would be suitable.
- Dinner: Another protein and vegetable, along with a full salad, such as 2 cups of lettuce or vegetables with 2 tablespoons (tbsp) of dressing. Four oz of beef or fish, 2 oz of cheese, or 8 oz of milk also counts as one protein serving.
The GreySheet diet plan stresses lean proteins over carbohydrates. The Dietary Guidelines for Americans recommends avoiding or eating fewer processed meats, such as deli meats, hot dogs, and sausages. Better proteins to include in any dietary plan include:
- Poultry, such as chicken or turkey
- Nuts and seeds
- Legumes and beans
- Seafood, like salmon or shrimp
- Eggs
- Lean cuts of meat
Foods to Avoid on the GreySheet Diet
The GreySheet diet does not allow for any food between meals. However, you can drink black coffee, tea, or water. You should avoid sugary drinks, desserts, and other high-carb foods. The recommendations regarding limiting sugars mostly align with the Dietary Guidelines for Americans, which stresses avoiding or limiting foods like:
- Sugary drinks and desserts
- Foods that are high in saturated fat
- High-sodium foods
- Alcoholic beverages
Potential Benefits of the GreySheet Diet Plan
There is a lack of research into the GreySheet diet. But the plan’s intent is not specifically weight loss. Instead, it focuses on food addiction and similar eating disorders. In theory, if you follow the GreySheet diet’s guidelines, you will likely lose weight, especially if your regular diet includes a large amount of refined carbohydrates, added sugar, processed or fast foods, and alcohol. You may find that the program’s precise rules and portion sizes make it easier to follow than other diets that require counting calories, fat grams, or points. The diet’s emphasis on fresh produce and lean protein can increase your intake of fiber and certain essential vitamins and minerals, while decreasing your consumption of saturated fat, trans fats, and sodium. Another potential benefit is that to access the dietary plan, you’ll need to work with a sponsor. These people act as coaches to help you reach your goals, keep you motivated, and help provide some support.
Risks and Considerations of the GreySheet Diet
The GreySheet diet is not for everyone, and it may not work as a weight loss diet. It was designed to help with eating disorders like food addiction. Some reasons it may not work well for you include:
- Weighing and Measuring: Not everyone responds well to regimented control over food intake. This diet requires measuring your portions at every meal, with no snacks between meals.
- Lacks Clinical Evidence: Like many dietary plans, the GreySheet diet has very limited to no studies or evidence to back up its effectiveness.
- Limited Support for Other Lifestyle Changes: While the diet addresses food intake, it does not encourage other lifestyle changes (like regular exercise) that can have a significant impact on long-term, sustainable weight loss. If you follow the GreySheet diet and then return to your previous eating habits, you may regain any of the weight you lost.
Is the GreySheet Diet Right for You?
You should talk with a doctor or a registered dietitian before you try the GreySheet diet or any other fad diet. There is limited evidence suggesting this diet’s safety or success for the average person. What’s more, talk therapy (such as cognitive-behavioral therapy) is typically recommended for people struggling with eating disorders, so that they can address the underlying causes and triggers. Antidepressants and other medications may also be used as part of a treatment plan. If you feel like you may be living with an eating disorder, talk with a doctor. They can help identify and treat food-related conditions or help connect you with therapists who specialize in these disorders.