The Similarities, Differences, Benefits, and Pitfalls of Vegetarian, Vegan, Paleo, Primal and other Diets

 In Diet

“Tell me what you eat, and I will tell you what you are.”

Jean Anthelme Brillat-Savarin

Eating is an intensely personal act. When we eat, we symbolically consume identity through our food choices. What we choose – or don’t choose – expresses our beliefs, cultural and social backgrounds, and experiences and communicates them to others. From raw food to fast food to comfort food, our food choices are influenced by a variety of factors, even the amount of time we have to prepare and eat a meal. Primarily distinguished by what to eat and what not to eat, the most popular diets not only reflect these intensely personal factors, but also promise to help you manage your weight, prevent disease, heal your body, and soothe your soul. Since all these diets claim to be “The Best”, here’s a review to help you to know which ones are worth trying.

Vegetarian and Vegan

Vegetarians focus on eating foods of plant origin. Several subgroups fall under the vegetarian umbrella, including vegan, lacto vegetarians, lacto-ovo vegetarians, and pescetarians. Vegans follow a strict form of vegetarianism. Motivated to avoid animal exploitation and cruelty for ethical, environmental, or health reasons, vegans exclude all forms of animal products. Lacto vegetarians, lacto-ovo vegetarians, and pescetarians follow less strict forms of vegetarianism. Lacto-vegetarians include dairy, lacto-ovo vegetarians include dairy and eggs, and pescetarians include fish and seafood.

While plant-based diets have been linked with weight loss and a reduced risk of heart disease, type 2 diabetes, and premature death, one potential pitfall to following a vegetarian or vegan diet is the risk of developing nutrient deficiencies from eliminating animal products, particularly vitamin B12, vitamin D, iodine, calcium, iron, zinc, and essential fatty acids. Relying on poor quality processed foods as substitutes for animal products also puts followers at risk of developing nutrient deficiencies. Vegetarians or vegans with certain conditions, such as women who are pregnant, trying to get pregnant, or lactating, especially need to ensure that they’re meeting their nutrient requirements. Recommended supplements include B12, creatine, carnosine, taurine, and algal oil.

Another potential pitfall to following a vegan or vegetarian diet is the health risks from relying on soy and soy-based products as sources of protein. To put it bluntly, soy is bad. For example, the phytoestrogens in soy disrupt endocrine function, potentially causing infertility and breast cancer in women and decreased sperm count in men. Vegetarians or vegans who eat soy should make sure it’s non-GMO and as natural and unprocessed as possible, as in natto, tempeh, and unprocessed tofu.

Finally, vegetarian and vegan diets are very restrictive, making them difficult to follow for the long-term.

Mediterranean-Style and Clean Eating

One point of dispute among the popular diets is whether or not humans should eat grains. Among the pro-grain diets, research suggests that the benefits of following a Mediterranean-style eating plan include improved weight loss, better control of blood glucose levels, and reduced risk for heart attack, stroke, and Alzheimer’s disease. A way of eating based on the traditional foods and drinks of the countries surrounding the Mediterranean Sea, the Mediterranean Diet focuses on vegetables, fruit, whole grains, legumes, and olive oil. It features fish and poultry over red meat and full-fat dairy, which contain more saturated fat. Red wine is consumed in moderation with meals. The Mediterranean Diet also encourages incorporating traditional lifestyle aspects of the Mediterranean Sea countries into practice, such as sharing meals with family and friends.

Also pro-grain, clean eating focuses on eating whole, natural foods, limiting fat, sugar, and salt, and eliminating processed foods. Other tenets are to include some protein, carbohydrate, and fat at every meal and to eat five or six small meals throughout the day. Research suggests that eating this way prevents both skipping meals and overeating, keeping blood sugar levels steady throughout the day. Clean eating encourages choosing to drink water, unsweetened tea, low-fat or skim milk, and pure fruit juice diluted with sparkling water over high-calorie drinks like lattes and soda. Like the Mediterranean Diet, clean eating also encourages incorporating lifestyle aspects into practice, such as getting regular physical activity.

The main potential pitfall to the pro-grain diets involves the inclusion of grain. Arguments are strong that eating grain and grain-based products exact health costs for both humans and animals. Another potential pitfall involves the exclusion of saturated fat from dairy and red meat.

Paleo and Primal

Like clean eating, paleo focuses on eating whole, natural foods, but with an evolutionary foundation. According to paleo, most modern diseases can be linked to the consumption of grains, dairy, and processed foods. To be healthy, we should eat the way humans were genetically designed to eat before the advent of agriculture. The foods presumed to have been eaten by our paleolithic ancestors include meat, fruit, vegetables, nuts, seeds, and fermented foods. Paleo excludes coffee, dairy, grains, soy, legumes, tubers, and nightshades (potatoes, peppers, eggplant, and tomatoes). Studies have shown that paleo can be effective at reducing risk factors for heart disease, such as cholesterol, blood sugar, blood triglycerides and blood pressure. Paleo can also be effective for weight loss, as followers automatically eat much fewer carbs, more protein, and 300–900 fewer calories per day.

Like vegetarians, several subgroups fall under the paleo umbrella. While all versions of paleo reject grain products, sugar, and processed foods, a flexible form known as primal allows for some of the excluded foods, especially dairy. The best way to find out if you can eat any of these foods is to eliminate a food for a while and then add it back to see how you feel.

Offering structure, resources, and support, several branded programs have been established by respected paleo and primal movers and shakers. One such program, the Primal Blueprint, was created by Mark Sisson in the mid-2000s. For those who like and can tolerate them, the Primal Blueprint allows for full-fat dairy (preferably raw, fermented, and from pastured-raised animals), as well as coffee, tubers, nightshades, legumes, and oats. Designed as a lifestyle, the Primal Blueprint also focuses on many other factors of health, including quality of sleep, movement, and social connections. Key concepts of the Primal Blueprint include the 80/20 Rule and intermittent fasting.

Whole 30

Another branded program, Whole30, was created in 2009 by Dallas Hartwig and Melissa Hartwig. Addressing weight, energy, and stress levels, the 30-day diet emphasizes whole foods. Similar to paleo, foods allowed include meat, nuts, seeds, seafood, eggs, vegetables, and fruits. Foods not allowed include sugar, alcohol, grains, legumes, soy, dairy, and natural sweeteners like honey and maple syrup.


With the belief that food is medicine, Dr. Mark Hyman combined paleo and vegan to create pegan in late 2014. To get nutrients not available from plants, pegans supplement a base vegan diet with animal products like meat, eggs, shellfish, and organ meats. In 2015, Dr. Kellyann Petrucci introduced the Bone Broth Diet as a weight-loss and anti-aging program. The core of the 21-day program is paleo, plus fasting by drinking three to six cups of bone broth for two nonconsecutive days a week. Bone broth is a whole-food way of including important minerals in the diet, leaching calcium and magnesium, as well as protein from collagen and gelatin, from the bones.

The Bulletproof Diet

Unlike paleo and primal, the Bulletproof Diet came about through anti-aging, cognitive performance, and fertility research, not by focusing on ancestral health. Perhaps best known for Bulletproof Coffee, the Bulletproof Diet is based on high amounts of healthy fats and organic vegetables and moderate amounts of high-quality protein. The Bulletproof Diet focuses on reducing cravings and minimizing aging by focusing on food quality and how food works in your body on a biochemical level. The Bulletproof Diet also focuses on minimizing your body’s exposure to harmful chemicals and mold. Other tenets include one day per week of protein fasting and advice to gently cook your foods to conserve nutrients.


Atkins and Keto

By switching from carbohydrates to fat as your main source of energy, your body will more readily burn stored fat. Studies have shown that very low-carb diets, like the Atkins and ketogenic diets, are effective for weight loss. They are especially successful in reducing belly fat, the most dangerous fat that lodges itself in the abdominal cavity. Studies have also shown that low-carb diets reduce many risk factors for disease, including blood triglycerides, cholesterol, blood sugar, insulin, and blood pressure. However, because fiber is found only in plant, such as fruit, vegetables, and grains, low-carb diets tend to be low in fiber. Low fiber intake is associated with increased risk of colon cancer, heart disease, diabetes, and constipation.


The Atkins diet is split into four phases, starting with eating under 20 grams of carbs per day for two weeks. Subsequent phases involve slowly reintroducing healthy carbs back into your diet as you approach your goal weight. Because Atkins is not definitive about what to eat, one of potential pitfalls is that followers ignore food quality. Another potential pitfall is that Atkins can cause health problems such as acidosis.


A keto diet is designed specifically to result in ketosis, a state in which the body breaks down fat for energy instead of using glucose. Since it lowers blood-sugar levels and the negative impact of high insulin levels, a ketogenic diet is often used as an intervention for type 2 diabetes. One of potential pitfalls is that the diet requires at least a minimal level of monitoring to ensure ideal nutrient ratios.

The Wahls Protocol, the Autoimmune Protocol (AIP), and the Low FODMAP Diet

The Wahls Protocol

Some diets, including the Wahls Protocol, the Autoimmune Protocol (AIP), and the Low FODMAP diet, were purposely designed to address specific health issues. An integrative approach to healing chronic auto-immune conditions, the Wahls Protocol was created by Dr. Terry Wahls to address her progressive multiple sclerosis. Previously a vegetarian, Dr. Wahls was able to reverse many of her symptoms and improve her functioning by transitioning to paleo and incorporating exercise, toxin removal, and stress reduction into her life.


The Autoimmune Protocol (AIP) is a specialized version of the Paleo diet, with an even greater focus on nutrient density and even stricter guidelines for which foods should be eliminated. Foods can be viewed as having two kinds of constituents within them: those that promote health (like nutrients) and those that undermine health (like inflammatory compounds). The AIP diet works to calm inflammation in the gut and also calm inflammation in the body.


A group of short-chain carbohydrates, named FODMAPs (Fermentable Oligo-saccharides, Disaccharides, Monosaccharides, and Polyols) are problematic for those with irritable bowel syndrome (IBS). Found in a variety of fruits and vegetables and also in milk and wheat, these short-chain carbohydrates are poorly absorbed in the small intestine and rapidly fermented by bacteria in the gut. The production of gas by these bacteria is a major contributor to symptoms associated with IBS. The Low FODMAP diet was developed to control these symptoms.

How to Decide – What to ask yourself and take into consideration:

  • Time and organization – If you’re wondering whether you should change how you eat, it’s a good idea to think about your lifestyle. Are you ready, willing, and able to commit to doing what it takes to be successful?
  • Special circumstances – Is there a condition you have (or are trying to prevent) that what and how you eat will affect, like Lyme disease, fibromyalgia, multiple sclerosis, diabetes, cancer, fertility issues, Alzheimer’s, arthritis, celiac disease? Are you taking medications?
  • Your age – Results of a 2014 study examining links between protein intake and mortality suggest that low protein intake during middle age followed by moderate to high protein consumption in older adults may optimize health span and longevity.
  • Coffee – If you can’t live without it, you’ll want to know which diets restrict it and which diets allow it. The same goes for alcohol and attachments to certain foods.
  • Goals – What is motivating you to change how you eat? To lose weight? To improve your health? Know your “why”.
  • Values and beliefs
  • Cooking skills and willingness to cook or learn to cook
  • Your level of activity. Are you an elite athlete that requires more calories than the average person?

Tips for Success

  • Join my online 21 Day Transformation Challenge
  • Unless you’re an all-or-nothing kind of person, moving forward with changes in what you eat can be a gradual process. Start by upgrading the quality of your food and getting rid of sugar, grains, processed foods, and processed oils.
  • Rotating the same meals or menus, like an omelet or smoothie for breakfast, a salad for lunch, and a stir fry for dinner can help you avoid the tendency to obsess about food.
  • Using organizational tricks, like weekly shopping trips and meal prep, can help you stay on course. Having a Plan B, too, like keeping snacks on hand, can help, too.
  • Seek out and surround yourself with like-minded people. Change can be lonely, plus studies have shown that social relationships affect a range of health-related outcomes, including mental health and physical health.
  • Don’t fret about perfection (unless you have a special circumstance or goal)
  • Keep informed – fluid/dynamic field
  • Portion control – it’s easy to overeat high fat foods like nuts
  • Expand your horizons. Cultivate the habit of trying new foods or new recipes. Join a CSA (Community Supported Agriculture) and grow a garden.
  • Be mindful – make mindful, conscious, and conscientious decisions about how you nourish and tend to your body
  • Swap – Choose almond butter and dark chocolate instead of peanut butter cups
  • Keep an open mind
  • Listen to your body.
  • Eliminate foods that you think don’t agree with you and note changes in your skin, mood, brain and body etc
  • Keep it simple


In the Perfect Human diet – Barry Sears mentioned that nutrition is like religion and politics, based on belief systems. It’s time that we treat nutrition with facts. Instead of looking at the difference between these diets, let’s acknowledge that they all generally work and that is because they all fundamentally similar. That is if you want to be healthy for long-term eat good fats and plenty of various vegetables. It doesn’t have to be complicated!


As with any change in your life, you should consult a trusted and competent health professional before embarking on any new lifestyle changes. This is critical if you are on any prescription drugs or supplements.

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