January 1, 2017 @ 6:00 PM · Nutrition

By Karen Gilchrist

When one hears or sees the word diet, the context in today’s times often relates to weight loss. All too frequently, it may seem, a new plan appears, promoted by testimonials from doctors, celebrities and satisfied followers alike and “guaranteed to help you lose weight, and keep it off!” And indeed, a veritable smorgasbord of diets, from plant- and meat-based plans to highly restrictive and body-specific regimens, exists to address not only weight loss, but also weight gain, health conditions and just plain healthy living for longevity. 

According to Oxford Dictionaries, the first known use of the word diet occurred in the 13th century. The Middle English word derives from the Old French diete (noun) and dieter (verb), via Latin from the Greek diaita, “a way of life.” Medical News Network describes a diet
“…as a set course of eating and drinking in which the kind and amount of food one should eat is planned out in order to achieve weight loss or follow a certain lifestyle.” By choosing to adhere faithfully to a specific diet, one truly does select a way of life, and each diet choice may offer particular advantages and/or potential shortcomings regarding nutrition, food choice options and ease of preparation and commitment.

But which to choose? Vegetarian or vegan? Primal or paleo? Blood type or low-carb? Gluten-free or raw? Is there a one-size-fits-all diet? Of course not, based on a number of factors, including an individual’s personal health and preferences and cultural influences. But while hundreds or even thousands of diets exist, most fall within a few main categories. Following is a by-no-means-complete list of some of the more popular diets people follow today, for weight loss and/or lifestyle.


Plant-based Diets

In their article “Nutritional Update for Physicians: Plant-Based Diets,” authors Phillip J. Tuso, MD; Mohamed H. Ismail, MD; Benjamin P. Ha, MD and Carole Bartolotto, MA, RD, provide a comprehensive definition of a plant-based diet, which seeks “to maximize consumption of nutrient-dense plant foods while minimizing processed foods, oils and animal foods (including dairy products and eggs).” Such a diet is generally low in fat and encourages eating plenty of cooked or raw vegetables, as well as beans, fruits, lentils, peas, seeds, soybeans and smaller mounts of nuts. Included in this definition are the following diets:

• Vegan or total vegetarian, which excludes all meat (beef, pork, lamb, poultry and seafood), eggs and dairy products 

• Raw food vegan, which excludes all meat, eggs and dairy products as well as all foods cooked at temperatures over 118°F

• Lacto-vegetarian, which excludes all meat and eggs but allows dairy products 

• Ovo-vegetarian, which excludes all meat and dairy products but includes eggs

• Lacto-ovo vegetarian, which excludes all meat but includes eggs and dairy products

• Whole-foods, plant-based, low-fat, which encourages plant foods in their whole form, especially fruits, legumes, nuts (in smaller amounts), seeds and vegetables, but limits animal products and total fat

• Mediterranean, which is similar to a whole-foods, plant-based diet but allows consumption of small amounts of chicken, dairy, eggs and red meat once or twice monthly. Fat is not restricted, and fish and olive oil use are encouraged. 

Other popular plant-based diets, which are variations of vegan and vegetarian approaches, include 

• Pesco-tarian – excludes all meat but seafood 

• Flexitarian – follows a vegetarian diet most of the time but allows meat on occasion

• Ornish – categorizes five food groups from most to least healthful and includes exercise, stress management and emotional support options as part of the lifestyle

• Traditional Asian – emphasizes rice, vegetables, fresh fruit and fish and very little red meat 

• Anti-inflammatory – based on the Mediterranean diet and on a daily intake of 2,000 to 3,000 calories, with 40 to 50 percent of calories from carbs, 30 percent from fat and 20 to 30 percent from protein

• Engine2 – eliminates all vegetable oils from a vegan diet

• Eco-Atkins – recommends 31 percent of daily calories from plant proteins, 43 percent from plant fats and 26 percent from carbs, incorporating fish, lean white meat and occasional dairy products if desired

• Macrobiotic – emphasizes natural, organically and locally grown, whole foods and eschews anything artificial, processed or with chemical additives 


Low-carbohydrate Diets 

Growing in popularity in recent years, low-carbohydrate (or reduced-carbohydrate or low-glycemic) diets restrict consumption of foods high in carbohydrates. Laura Dolson, a health and food writer who has been investigating the emerging science related to low-carb eating for 10 years, notes that such diets can be defined by how much carbohydrate is in a diet, what percentage of calories derive from carbohydrate or how low “low” is. Since the U.S. Dietary Guidelines and similar sources for the general public recommend that carbohydrates make up 50-65% of the calories in a diet, anything less can be considered “low-carb,” and studies of low-carb diets show ranges from 45% to 5%. As with many plant-based diets, some low-carb plans, which reduce or eliminate sugars and refined grains, follow strict regimens while others allow flexibility, from simply reducing carbohydrate intake to finding an individual’s tolerance level for carbohydrates.

• Atkins Diet, a four-phase approach that counts carbohydrate intake regardless of source, greatly restricting consumption in the first phase and seeking the optimal tolerance by gradually adding nutrient-dense carbs and avoiding refined grains and sugars

• South Beach Diet, a flexible three-phase plan based on principles of the Mediterranean diet that restricts saturated fats and most types of carbohydrates at first, progressively adding carbohydrates and a little more saturated fat in the third phase

• Zone Diet, an approach based on three meals and two snacks per day, with every meal composed of 30% protein, 30% fat and 40% carbs, which are mostly fruits and veggies, avoiding those high in sugar  

• Sugar Busters, a non-restrictive lifestyle diet that avoids refined sugars and processed grain products and promotes consumption of high-fiber vegetables, whole grains, fruits and lean and trimmed meats


Specialized Diets

For some people, such as those who suffer from severe allergies or sensitivities to or diseases exacerbated by particular foods or components of food, like gluten, diets specific to health conditions or body types become necessary lifestyles, yet others may reap benefits from following them as well.

• Gluten-free Diet – Gluten is a common name for proteins in specific grains. The two main protein groups in gluten, gliadins and glutenins, break down during digestion. But when people with celiac disease or gluten sensitivity eat gluten, their body’s immune response attacks the small intestine, leading to damage on the villi, small fingerlike projections lining the small intestine. Damaged villi prevent proper absorption of nutrients, potentially leading to delayed growth, nutrient deficiencies, anemia or osteoporosis or even resulting in diabetes, other autoimmune diseases and intestinal cancers (celiac.org, glutenfree.com). Those who cannot tolerate gluten must avoid wheat, rye, barley, triticale, durum, einkorn, Kamut® khorasan wheat, semolina, spelt/spelta, faro and emmer, as well as other common products likely to contain them, such as beer, bread, cakes and pies, candies, cereals, cookies and crackers, croutons, French fries, gravies, imitation meat or seafood, matzo, pastas, processed luncheon meats, salad dressings, sauces (including soy sauce), seasoned rice mixes, seasoned snack foods (potato and tortilla chips), self-basting poultry, soups and soup bases, vegetables in sauce, cosmetics, vitamins and some pharmaceutical medications (glutenfree.com).

• Blood Type Diet – Based on the premise that the foods an individual eats react chemically with one’s blood type, and that certain blood types are more susceptible to specific kinds of health issues, a diet and exercise plan based on that blood type will facilitate more efficient digestion for greater weight loss, higher energy levels and better disease prevention. This fairly restrictive diet suggests a high-protein diet heavy on lean meat, poultry, fish and vegetables and light on grains, beans and dairy for Type O blood; a meat-free diet based on fruits, vegetables, beans and legumes, and whole grains for Type A blood; a diet avoiding chicken, corn, wheat, buckwheat, lentils, tomatoes, peanuts and sesame seeds and focused on green vegetables, eggs, certain meats and low-fat dairy for Type B blood and a diet including tofu, seafood, dairy and green vegetables and excluding caffeine, alcohol and smoked or cured meats for Type AB blood.

• Ketogenic Diet – A ketogenic diet is a very low-carbohydrate diet that sends the body into ketosis so it burns fats, broken down in the liver into fatty acids and ketones, rather than carbohydrates for use as energy. The general recommended diet makeup is 60% fat (monounsaturated and saturated fats like coconut oil, butter, olive oil, avocados, cheese), 35% protein and 5% carbohydrates. Already well-established as a treatment for epilepsy, the ketogenic diet may help other conditions as listed in a June 2013 paper by A. Paoli et al in the European Journal of Clinical Nutrition, including weight reduction; type 2 diabetes; cardiovascular risk factors; neurological diseases other than epilepsy such as Parkinson's disease, Alzheimer's disease, narcolepsy, brain trauma and amyotrophic lateral sclerosis; polycystic ovarian syndrome; acne and some types of cancer.


Paleolithic or “Caveman” Diets

When one thinks of the “caveman” diet, images of loin-cloth-draped carnivorous groups of people hunkering down to consume the meat of a successful hunt may arise. Surely no one eats such a diet in modern times! Yet one can look to the experiences of Dr. Vilhjalmur Stefansson, a Canadian ethnologist who spent more than a decade with the Inuit in the early 1900s and who, for nine years, lived almost exclusively on fish and meat with no ill effect on his health, a diet he repeated as part of a study by Walter S. McClellan and Eugene F. Du Bois and detailed in their paper “Clinical Calorimetry: XLV. Prolonged Meat Diets with a Study of Kidney Function and Ketosis,” published in the Journal of Biological Chemistry in 1930.

Paleolithic diets are based on the premise that one eat as man ate prior to the cultivation of crops, a diet which would have included meat, berries, nuts, seeds, any regional vegetables and leafy greens found while hunting and foraging. Today’s low-carb, grain-free paleo or primal lifestyle diets, ever-growing in popularity, include more than meat alone and incorporate physical exercise as an important component. Robb Wolf, author of The Paleo Solution: The Original Human Diet, lists fruits, vegetables, lean meats (preferably grass-fed or pastured), seafood (wild), nuts and seeds and healthy fats as okay to eat. Foods to avoid are dairy, grains, processed foods and sugars, legumes (beans, peas and peanuts), starches and alcohol. The Primal Blueprint by Mark Sisson follows a similar diet plan, while allowing occasional consumption of dairy, alcohol, dark chocolate, supplements, herbs & spices, beans, legumes, potatoes and rice according to the 80/20 rule: if you stick to the primal diet 80% of the time, it’s okay to eat those occasional foods when “…circumstances don’t allow 100% Primal” (think traveling or a celebration).

So, does an optimal diet exist? Yes, the one that works for each individual within the contexts of health, culture and lifestyle choices. One may choose to become a vegan for personal, ethical or religious reasons, but a vegetarian diet high in refined sugar or “bad” oils is not healthy. Someone with multiple job and family responsibilities may not have the time to commit to a diet lifestyle that requires significant preparation or sourcing of specific foods. 

Notably missing from all of the diets outlined above are refined sugars and processed foods, focusing instead, depending upon the plan, on fruits, vegetables, lean meats, whole grains and healthy oils. So, yes, you are what you eat, and choosing a healthy, nutritious approach to eating that works for the individual may aid in achieving optimal health, naturally.

Karen Gilchrist is a writer, yoga instructor and longtime resident of Southern Pines. A complete list of sources used in this article can be found at www.sandhillsnaturally.com. 




Nutritional Update for Physicians: Plant-Based Diets


“Best Plant-based Diets,”


“What are the eight most popular diets today?” www.medicalnewstoday.com/articles/5847.php


Laura Dolson, “What Is a Low-carb Diet?”


Laura Dolson, Atkins Diet: Overview, http://lowcarbdiets.about.com/od/atkinsdiet/p/atkinsintro.htm


Laura Dolson, South Beach Diet: Overview http://lowcarbdiets.about.com/od/southbeachdiet/p/sbdintro.htm

The Zone Diet, www.webmd.com/diet/zone-what-it-is

Sugar Busters!, www.sugarbusters.com/filessb/concept.html






“The Beginner’s Guide to the Paleo Diet,” www.nerdfitness.com/blog/2010/10/04/the-beginners-guide-to-the-paleo-diet/

“Two Brave Men Who Ate Nothing But Meat for an Entire Year,” http://inhumanexperiment.blogspot.com/2009/09/two-brave-men-who-ate-nothing-but-meat.html

Walter S. McClellan and Eugene F. Du Bois, “Clinical Calorimetry: XLV. Prolonged Meat Diets with a Study of Kidney Function and Ketosis,” J. Biol. Chem. 1930, 87:651-668, www.jbc.org/content/87/3/651.full.pdf+html

 “What Is the Paleo Diet,” http://robbwolf.com/what-is-the-paleo-diet/

“What can I eat on the primal diet? There seems to be disagreement,” http://theprimalchallenge.wordpress.com/2011/09/16/what-can-i-eat-on-the-primal-diet-there-seems-to-be-disagreement/

“Dear Mark: 80/20 Revisited,” www.marksdailyapple.com/dear-mark-8020-revisited/#axzz37rdyevDr