Debunking Diets: 4 Popular Diets Explained

It seems like everywhere you turn there is a new diet trend being touted to the masses. Social media and television do a good job of promoting diets and food trends, often without credibility or review by a nutrition professional. With so much nutrition information floating around from non-experts choosing a way to eat can be a confusing and misleading journey. This post outlines the basics of four current diet trends, why they are so popular, and how they rank, to help you navigate your way to better eating.

The Paleo Diet

The Paleo Diet is advertised as a way of eating based on “pre-historic humans.” Foods included in the diet are ones that would have been eaten during the Paleolithic era, obtained by hunters and gatherers. A paleo diet encourages meats, eggs, fish, vegetables, fruits, nuts, and seeds – omitting all grains, dairy, and processed foods. Grass-fed animal products and fatty fish, like salmon and mackerel, are encouraged, while legumes, such as peanuts and peas, are not permitted in the Paleo diet.

This diet advertises itself as a way to restore food consumption to pre-industrial times before food was created in a lab or loaded with additives. The paleo diet restricts all whole grains and legumes, which can provide good sources of fiber, vitamins, and minerals. Although I like the Paleo Diet’s emphasis on proteins and fresh produce, it can be very restrictive and may not be ideal for some individuals, including growing children, those with limited resources, and those with high calcium needs.

The Paleo Diet. Kris Gunnars. Healthline. Retrieved September 8th, 2019.

The Ketogenic Diet

The Keto-craze has been sweeping America with promises of “rapid weight loss.” Eating “keto” means consuming a very low-carb, high-fat diet in order to create the metabolic state of ketosis. When ketosis is triggered, your body can more efficiently burn fat as fuel, rather than glucose. The “classic” ketogenic diet is a specialized high-fat, low-carbohydrate diet that helps to control seizures in some people with epilepsy. Doctors may recommend the ketogenic diet for children whose seizures have not responded to several different seizure medications. The typical ketogenic diet provides 3-4g of fat for every 1g of carbohydrate or protein. For use in children with seizure disorders, the diet is carefully monitored by a physician and dietitian[1].

“Rapid weight loss” may sound great, but the keto diet is very restrictive. All grains, starches, processed foods, and most fruits are prohibited. Foods with complex carbohydrates like peas, beans, sweet potatoes, carrots, and any fruit except a small portion of berries are also not allowed on the keto diet. Meat, fish, eggs, butter/cream, cheese, nuts, seeds, oils, and low-carbohydrate veggies are encouraged. Withdrawals from carbohydrates (your body’s preferred source of fuel) may cause “keto flu,” which can include dizziness, drowsiness, muscle aches, nausea, and irritability.

With the removal of whole grains, fruits, and some vegetables, you lose many essential vitamins and fiber sources. Since carbohydrates are replaced with fat and protein, higher than ideal levels of dietary saturated fats can quickly surmount. Eating lower-carb *may* be a good idea for weight loss, however, not at the expense of eating excess saturated fat and inadequate fiber. Healthy fats (olive oil, avocado, nuts, and seeds) are a vital part of your diet, along with plenty of fruits and vegetables to ensure you are getting adequate fiber. Finding a sustainable balance between lean protein (fish, chicken), nutrient-dense vegetables, fruits, and fiber-rich carbohydrates will better ensure weight-loss success in the long term.

The Low-FODMAP Diet

If you struggle with a very sensitive GI system, or Irritable Bowel Syndrome (IBS), then the Low-FODMAP Diet may be worth looking into. FODMAP stands for fermentable oligio-, di-, mono-saccharides and polyols. These FODMAP foods are a group of specific carbohydrates that can trigger digestive distress, including cramping, bloating, and gas. FODMAP’s are found in many healthy foods, such as legumes, fruits and vegetables, in varying amounts. A Low-FODMAP Diet temporarily restricts foods that contain high levels of the FODMAP carbohydrates, in order to reduce stomach symptoms and inflammation. These foods are only removed temporarily, and then slowly reintroduced back into the diet after a period of elimination.

For people with IBS, stomach pain is very common and often severe enough to interfere with daily life. However, if you do not experience stomach symptoms with High FODMAP foods, then there is absolutely no reason to restrict them! It is important to note that the FODMAP diet is intended to help people with IBS identify specific foods that may be irritating them. The diet is best used under the guidance of a Registered Dietitian which can help reintroduce foods in the proper timing and amount.

A Non-Comprehensive List of High-FODMAP Foods:

Chart of foods to avoid
What is a Low-FODMAP Diet and Who Should Try It. Amy Myers. Retrieved September 8th, 2019.

The Mediterranean Diet

Unlike other popular diets, the Mediterranean diet doesn’t emphasize the removal of entire food groups (thank goodness). Rather, the Mediterranean diet encourages consuming a wide variety of fruits, vegetables, lean protein sources, and heart-healthy unsaturated fats like nuts, seeds, and vegetable oils. The diet encourages consuming fish at least twice a week while limiting red meat to no more than a few times a month. Replacing butter with healthy unsaturated fats such as olive oil and canola oil is also suggested. The Mediterranean diet emphasizes lifestyle choices such as enjoying meals with family and friends, getting plenty of exercises, and drinking red wine in moderation (optional of course)!

According to the Harvard School of Public Health, the Mediterranean diet is “possibly the best diet ever!”[2] Research suggests that the benefits of following a Mediterranean-style eating pattern can include improved weight loss, better control of blood sugar levels, and even a reduced risk of depression. Eating Mediterranean has also been associated with reduced levels of inflammation, reduced incidence of cancer and cardiovascular disease. The Mediterranean diet is one of my favorites due to its well-rounded nature and its emphasis on heart-healthy fats, as well as encouraging a variety of plant fibers. Check out my previous blog post, 5 Fast Facts on the Mediterranean Diet for more details!

A Diet with No Restrictions: The Mediterranean Diet. Penn Medicine. Health and Wellness. Retrieved September 8th, 2019.

Congratulations! You are now well versed on a few of the 4 most popular diets in today’s culture. My advice: Opt for a Mediterranean-like, whole foods-based lifestyle. Choose high fiber and nutrient-dense foods, like veggies, fruits, and lean proteins. Go for unrefined whole grain products like quinoa or brown rice. Try to stick to products with ingredients that you recognize. Don’t restrict, especially if you feel hungry; this only leads to over-eating later in the day. If you do over-indulge every once in a while, don’t sweat it (stress and guilt can impair digestion). Be present, chew slowly, and enjoy meals with family and friends. This way your nutrition practice becomes a sustainable lifestyle choice, rather than a crash diet. Balanced nutrition and lifestyle choices lead to powerful health effects over time.

Co-created with Molly Pelletier, Yoga Instructor & Nutrition Student at Boston University.


[1] Ketogenic Diet. Epilepsy Foundation. Dietary Therapies. Retrieved November 13, 2019.

[2] Nutrition News: Widely studied Mediterranean diet linked to good health. Harvard School of Public Health. (2011)   Retrieved March 10th 2019.

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