Pros and Cons of Popular Diets

We checked in with our Registered Dietitian, Carol Bell, to get her take on the top 4 most popular diet trends. She shares the pros and the cons and some real-world dietary advice to reach your healthy weight. 

It is a pretty weird hobby, but I read diet books for fun. A few are worth reading cover to cover, but many aren’t. 

We want to answer the questions:

• What is the best diet to follow?
• How do I know if this approach is right for me? 
• What are the pros and cons of this plan?  

A good eating plan can do a lot for your body:

• alleviate pain
• improve digestion
• improve brain function
• support immunity
• boost your heart health
• help you lose weight

However, there are many approaches to choose.  This guide is an overview of some popular dietary plans. Ultimately, the one that is right for you is one that feels good when you follow it. You begin healing and feeling more energetic.

Keep in mind that a healing diet may be different from a maintenance diet. Eating habits have to evolve as your health changes so remember to stay flexible and LISTEN to how your body is responding to the things you are eating from week to week and season to season. You may follow a plan for a while, but then begin to feel your body’s needs change and need to tweak some details.  

Thoughts on the most popular dietary plans:

Overview:  The Mediterranean diet is a broad plan that includes a variety of foods from all food groups. It places the most emphasis on fresh fruits and vegetables, whole grains, beans, nuts, olives and olive oil and small amounts of meat, fish and dairy products.  Recipes have origins from Italy, Sicily, Greece, Turkey, southern France or the Middle East.

Sample meals: Breakfast: fresh fruit, rustic breads, and yogurt; Lunch: tomato-cucumber salad, white bean and vegetable soup, spinach pie; Dinner: Baked fish with herbs, potatoes and green beans simmered in tomato sauce

Pros: Easy to follow; inexpensive; widely available foods and easy to eat out in restaurants

Cons:  Generous use of olive oils increases calories of meals; Not designed for substantial weight loss; Places a lot of emphasis on nightshade vegetables (tomatoes, peppers, potatoes, eggplant) which may contribute to pain for some people.

Best for:  Healthy overall diet; taking a first step in making healthy changes; diabetes improvement; lowering risk for heart disease, cancer and neurodegenerative disease.

Overview: The DASH diet (Dietary Approaches to Stop Hypertension) is a step up from the Mediterranean diet and has a few more specific guidelines and great support from research. It places emphasis on 5-9 cups of fruits and vegetables every day, whole intact grains, beans, peas, nuts, seeds and lower intake of meats, fish, eggs and dairy.

Sample Meals:  Breakfast: Whole grain cereal with fresh fruit and milk; Lunch: Chicken-apple-celery salad over leafy greens with whole grain bread, melon; Dinner: Grilled salmon with redskin potatoes and sautéed spinach and carrots.

Pros: Evidence based benefits; easy to follow; inexpensive, widely available foods and easy to eat out in restaurants

Cons: Requires some home cooking; not designed for substantial weight loss

Best for: Healthy overall diet; taking a first step in making healthy changes; Improving diabetes or gestational diabetes; lowering blood pressure

Overview:  Vegetarian/ Vegan Diet/ Nutritarian diet is a plant-based plan that excludes either most or all animal products. The emphasis is on eliminating processed foods and eating a variety of fruit, vegetables, beans, peas, whole grains, nuts and seeds. 

Sample Meals: Breakfast: Cooked oatmeal with almonds, flax seeds and fresh fruit; Lunch: Black bean burrito on a whole grain tortilla with tomatoes, avocado, shredded carrot & microgreens;  Dinner: Lentil and kale soup, cooked quinoa on top of a large romaine salad with cucumber, carrot, cabbage, almonds, raisins and lemon vinaigrette.

Pros:  Simple meal preparation; Inexpensive as beans and grains are cheap compared to meat and fish; Solid, evidence-based research on benefits for weight loss, diabetes, cardiovascular disease and cancer prevention. Lower mortality rate and overall long-term health in the general population among vegetarians. Lowers cholesterol levels and lipids.

Cons: May require more home cooking to eat well; Vegan “junk food” is widely available (ex: soy hot dogs) and not beneficial to eat;  harder to eat a proper vegetarian meal in restaurants – they often serve just pasta with vegetables.  Vegan diets require nutrient supplementation of B12, iron, and others. 

Best for: Limited food budget, weight management, cardiovascular disease, diabetes, liver disease, cancer prevention. 

Overview: The Paleo Diet is based on whole, unprocessed foods and includes meat, fish, eggs, vegetables, fruit, nuts and seeds.  It excludes dairy products for the allergenicity, and grains and legumes on the basis that they were not likely part of an ancestral diet 10,000 years ago and may include some components that are not ideal for digestion.  It is not necessarily a low carbohydrate diet but could be designed that way. It may limit calcium intake unless there is enough emphasis on green vegetables and nuts and seeds. The Autoimmune Protocol is a version of the paleo diet that serves as an elimination diet for a trial period to detect inflammation triggers.

Sample Meals: Breakfast: Broccoli and egg frittata, apple; Lunch: Pastured beef burger on a portobello mushroom “bun” with sweet potato wedges and a romaine and red cabbage salad; Dinner: Baked rainbow trout, roasted carrots and parsnips, steamed cauliflower and green beans.

Pros: Socially acceptable “diet”; Makes for a good elimination diet to determine common food triggers like gluten or dairy. May be a good transition for many people coming from a standard American diet; Promising research in using the Autoimmune Protocol diet for autoimmune conditions. 

Cons: Pastured, grass fed meats and wild caught fish are very expensive;  Can be  low in fiber; Conventionally raised and processed meats may contain harmful pesticides, undesirable fats and additives.  May elevate cholesterol levels. 

Best for: Digestive concerns; food sensitivities to gluten, grains, legumes, dairy; some autoimmune conditions (Autoimmune Protocol diet).

Overview: The Ketogenic Diet or “Keto diet” is a popular weight loss diet. It was originally created to control symptoms of epilepsy in those reacting to medications. It emphasizes that most dietary calories (80% or more) come from fat while using some protein (15%) and very little carbohydrate (5%). (To contrast this– a more moderate approach of the Mediterranean diet is about 25% fat, 20% protein and 55% carbohydrate.) The keto theory is that substances called ketone bodies are made in the liver from fat to fuel energy levels rather than using glucose made in the liver or derived from foods. It is designed to help users lose weight.  It excludes all grains, beans, most fruits, and many types of colorful vegetables while promoting generous consumption of meats, fish, eggs, avocado, oils and fats, nuts and seeds.

Sample Meals: Breakfast: Bacon and eggs, spinach and yellow squash; Lunch: Chicken breast on romaine lettuce with avocado, almonds, bell peppers, radish, olive oil and lemon vinaigrette; Steak strips wrapped up in a steamed collard green with cauliflower and a cashew-lime dipping sauce.

Pros: High satiety, feel full and content after meals; Socially acceptable diet; minimizes sugar cravings after a few days to a week; begins showing weight loss within a week of starting 

Cons: Micronutrient deficiencies may result; low fiber diet may create higher long-term risk for bowel diseases or cancer. Some weight loss may be water loss initially – may lead to dehydration; alters composition of the gut microbiome to favor less desirable types of bacteria—long term consequences of this change is unknown. Could alter blood lipids – higher triglycerides and cholesterol – or lead to fatty liver in some people; hard to adhere to long term, burnout rate is high after a few months. 

Best for: Uncontrolled epilepsy; short term weight loss

The ultimate question, of course is, “Will this way of eating help me live a longer, healthier life?” 

 After many years of watching diet trends come and go, we often see the more extreme forms of eating as less beneficial than balancing the intake of a variety of foods.  A therapeutic diet that is helpful for one person may not always be right for other people, so it is harder to generalize on specifics like intake of meat, eggs, dairy or grains.  What all great eating plans have in common are a few things:

1. Reduce or eliminate processed foods, refined sugar, caffeine and alcohol.
2. Emphasize that the majority of the diet is based on vegetables and fruit as the “base of the pyramid”.  
3. Protein intake would come more often from beans, peas, intact grains, nuts and seeds (daily) and less often than meats, fish, eggs and dairy (few times a week).
4. Fats in the diet come from whole foods like nuts, seeds, avocado, fish, and olives rather than from refined cooking oils and solid fats. 
5. Generous use of teas, herbal teas, green herbs, and aromatic spices. s