Do you know what to eat?

A review of popular diets

We are all our own unique chemistry experiment. Your microbiome unique and your genes have some small differences too. Environment, stress factors – those can play a role too. There is no one diet that is right for everyone. There is not even one diet that is right for you forever. Your body changes and so does its requirements.

Research continually unveils mysteries of the interaction of food and the body. Or at least it thinks so. Your body is designed with a blueprint made many hundreds of years ago.

If you seek a caring professional who is a registered naturopathic doctor in Guelph with a functional medicine approach, you’ve come to the right place. Dr. Laura M. Brown, ND knows how to stimulate your body’s natural mechanisms to repair damage and rebuild health.

Why all the differences in diets?

You need the basics to keep your body fit and functioning. Healthy fats build cell membranes, insulate your nerve fibres and construct hormones for good message conduction. Proteins are the building block of DNA, RNA, muscle, bone, organs and neurotransmitters. Bet you’d like to have some of those. Carbohydrates provide energy to think, move and build your body. Who doesn’t want that? Finally, you need lots of vegetables to provide the polyphenols, minerals, antioxidants, fibre, flavonoids, phytosterols, (and many more plant compounds) that help you eliminate toxins and waste. Did you know vegetables have over 5,000 compounds known, plus many more that are likely yet to be discovered? 

South Beach 

There is the South Beach diet of the 70’s that promised weight loss with low carbs. Currently it proports to be the easier to follow Keto diet. It provides healthy fats (50-55% of daily calories), quality carbs (50g net carbs per day) and lean protein (25% to 30% of daily calories)[1].


High-fat diets are known to increase inflammation, intestinal permeability and shifts in location of bacterial colonies[2]. It may however, depend on the type of fats.  Keto diet provides less than 50g of carbohydrate a day, forcing the body to switch from a carbohydrate fuel burner to a fat fuel burner. Traditionally ketogenic diets were helpful for those suffering from seizures and metabolic concerns. Short term (3-6 months) adherence to a keto diet may help reset your insulin sensitivity and mobilize the body’s ability to burn fat (lose weight). Long term keto may impair thyroid function and add stress to a body not in need of insulin sensitivity repair and weight control. In addition to seizures, it’s better for those with insulin dysregulation and who are overweight[3]. Once the insulin is reset and the weight is lost, it’s likely time to switch your diet. 


Then Atkin’s diet of the 80’s that promised weight loss with a low carb, low sugar approach.  It is somewhere between the South Beach and the Keto. 


The Ornish diet which has a focus on quality foods overall and more plant-based foods in their natural form. Which is pretty close to the whole 30 diet, eating whole foods (no processed or packaged) for 30 days. Difference is the whole 30 completely eliminated dairy, sugar or sweeteners of any kind, no alcohol, baked goods, junk foods, grains, legumes, carrageenan, MSG or sulfites.   

Vegan, Vegetarian, Pesco-vegetarian

Some people find they digest plant-based foods better. Vegan (no animal products whatsoever) and vegetarian (will eat dairy and eggs but no other animal products) have also been around for ages. The pesco-vegetarian eats the same as the vegetarian plus fish. The pesco’s have to be careful to rotate their fish sources to avoid heavy metal contamination from waterways. 


It doesn’t end there. The Mediterranean diet invented by Americans in the 1960’s mimicked the foods consumed by coastal regions of Italy and Greece.  Its focus is a high consumption of olive oillegumesunrefined cerealsfruits and vegetables.  There is moderate to high consumption of fish, small amounts of non-fish meat products. Mediterranean eaters include a moderate consumption of dairy products (mostly as cheese and yogurt) and a little wine to wash all that down.  It is thought the higher consumption of olive oil and lack of processed and packaged foods is the major contributor to the improved health of those who follow it. 


The DASH diet (Dietary Approaches to Stop Hypertension) is another diet with a strong focus on fruit, vegetables, whole grains, nuts, low fat and non-fat dairy, lean meats, fish and poultry and heart healthy fats.  In 2018, the DASH diet actually merged with the Mediterranean diet. Essentially the Mediterranean diet is everything in the DASH diet drizzled with a lot of olive oil.  


Macrobiotic diet is based on Traditional Chinese Medicine and the principles of yin and yang (balance of heat, sweet, salty, savoury and coolness) in foods. The focus is on locally grown, seasonably available sources.  It combines a variety of whole cereals and grains with beans and vegetables, with small amounts of white fleshed fish, nuts, seeds and fruits. 


Paleolithic diet is one like our ancestors ate millions of years ago. Paleo eaters include meats, especially organ meats, fish and shellfish, eggs, fruits and vegetables, nuts and seeds, herbs and spices, and starches like potatoes and sweet potatoes, along with healthy fats. Although not likely in our ancestral diet, some paleo followers include full-fat dairy products and some legumes. Paleo-autoimmune diet restricts the consumption of one or all of the following: nuts, eggs, grains, beans, legumes, dairy, eggs, nuts, seeds, nightshades (tomatoes, potatoes, eggplant and peppers), as well as food chemicals and additives.

Specific carbohydrate

The specific carbohydrate diet is designed for those with Crohn’s, ulcerative colitis, diverticulitis, celiac disease, cystic fibrosis, and chronic diarrhea. The essence of it is to provide very specific carbohydrates with the goal to heal the gastrointestinal tract. It is an alternative to the high fibre, low fat, low residue, anti-yeast, gluten free diets often offered as an aid to inflammatory bowel conditions. Removal of certain carbohydrates, especially lactose and sucrose and any other compound of sugar or carbohydrate. Only glucose is readily absorbed. It is believed that bacterial overgrowth in the small intestine prevents enzymes from breaking down carbohydrates. Thus, the food is left undigested and undergoes fermentation.  The undigested foods, abrasive microbial toxins acids lend to a harsh environment that triggers release of excess mucus to soothe the lining and lubricate the flow.  Let’s expand more with a note on FODMAPS. They may be a major cause of the diarrhea part of IBS.


FODMAPs are fermentable oligo-, di-, mono-saccharides and polyols. Not only is that a mouthful, the list of FODMAP foods is extensive and can make eating a real challenge.  That’s where a food sensitivity test will help to narrow things down for you. Otherwise, you may choose to try the FODMAP free diet, as a process of elimination for three months, then like with the food sensitivity avoid and re-introduce one by one after three months. 

Just like those with a lactase enzyme deficiency cannot effectively process milk products with lactose in it, those with large intake of fructose or other FODMAP foods may overwhelm their digestive capacity of the small intestine. In those with sensitivities, the FODMAP passes through the small intestine undigested and then when it reaches the large intestine, it ferments. 68% of the world is lactase deficient. This reaches as high as 100% in the Han Chinese population.  It is quite common to be sensitive to milk-based foods. There is more than just lactose, sugar and gluten sensitivity, when it comes to FODMAPS. “As many as 70%-80% of patients with IBS may benefit, to a certain degree, from the low-FODMAP diet,” says Eamonn M. Quigley, MD, director of the Lynda K. and David M. Underwood Center for Digestive Disorders at Houston Methodist hospital[4].

FODMAPS include five categories of sugars: fructose, fructans, lactose, polyols, and galactans. Levels of FODMAP will vary food to food. This means you may be sensitive to one and not the other, or you may be okay with a small collective amount, but must be careful not to overwhelm your system. If the microbiome imbalance is corrected, you may be able to go back to eating these foods again. This can take up to two years of abstinence – which is much longer than the initial three months of the first phase of the gut reset protocol. Just as you and me can be stubborn at times, so can those microbes in the gut!

Fructose is high in sugary foods like soft drinks and “high fructose corn syrup” is what is often found on the label.  It is also naturally occurring in white sugar, honey, many fruits and vegetables. Fruits that are dried and fresh ones like apples, mangos, pear and watermelon. Vegetables like sugar snap peas, artichokes and asparagus. 

Polyols you might recognize in “sugar free” labeled items. Watch for them in gum, mouthwash and toothpaste.  They include all the non-absorbed sugars ending in -ol. Sorbitol, mannitol, xylitol, maltitol. They are also found in apples, apricots, lychee, nashi pears, nectarines, peaches, pears, plums, cauliflower, mushrooms, snow peas and isomalt. 

When fructose is linked together in chains, it makes fructans. Fructans are high in wheat. They are also found in agave, artichokes, asparagus, leeks, garlic, onions (including spring onions), and rye. Now some of these are essential to feed the gut. You’ll note prebiotics include artichokes, asparagus, leeks garlic and onions and wheat. If you have an imbalance in your microbiome, and thus lack the appropriate enzymes to break down FODMAP foods in the small intestine, you can end up with fermentation of the fructans in the large intestine. This results in gas, pain and bloat constipation and diarrhea. The bloat can be really bad.  Some people I’ve seen bloat so much they look like they are pregnant! 

A food sensitivity test can help you understand what FODMAPs you could or shouldn’t eat. If wheat is one, which it is for many, perhaps apples won’t be. 

Non-celiac wheat sensitivity may be a sensitivity to FODMAPs. It also means that your diet drinks and chewing gum might upset your stomach too. It also might be what’s behind the ability to eat wheat in Europe and not in North America. 

What’s the difference between wheat (gluten, gliadin) sensitivity and FODMAP sensitivity?  FODMAPS cause GI complaints. Gluten and gliadin proteins, in the other hand, may or may not cause gastrointestinal complaints, while they do cause a lack of well-being in every part of the body. If you are to eat European wheat, which is lower in FODMAPS than North American wheat, you still get immune response, just not the GI complaints.

Galactans are also a FODMAP food. Chickpeas (garbanzo beans), legumes, lentils, pistachio nuts and cashews top this list. 

Breath tests can help determine the cause and symptoms of carbohydrate (FODMAP) malabsorption. SIBO (Small Intestinal Bacterial Overgrowth) can contribute to the issue.  

Avoidance of FODMAPs may help, but not fully stop the diarrhea in IBS. You may need to treat the overgrowth with a gut reset protocol and be sure to include three months of Saccharomyces boulardii (a type of probiotic). 

Eat right for your blood type

Eat right for your blood type. Have you heard of this one? Based on whether you are A, B, AB or O blood types, there are foods that may or may not sit well with you. Some people have had success following these diets. I first thought the broader world of research science hasn’t really found any distinct proof in how they might work. Then I looked into it a little. The theory is that the gene that codes for what blood type you get, affects nearby genes that code for other factors. In clinic I find it interesting that most people with O blood type do better on a diet that includes meat and vegetarians are often the ones with A or B blood types. That’s just my observation, however. Laura Power, PhD, published in the Townsend letter for doctors in June 1991. She found in her research the sensitivity people had to lectins and that some relationships tie to a person’s blood type. (Lectins are actually used in the lab to diagnose those with type A1 blood).  Lectins, when consumed in excess by those with a sensitive gastro lining, can cause intestinal damage, disrupt digestion and lead to nutritional deficiencies (malabsorption). Lectins are high in grains and (especially undercooked) beans like kidney and lima.  Curious as I am, I read Peter D’Adamo’s book Eat right for your blood type. (

Apparently, blood type diets have plenty of science to back up the concept of using your blood type to direct your food choices. According to the theory, O blood types do better with Paleo style diets, Type A’s are better with a macrobiotic, vegetarian or vegan. They typically do well with soy, where others do not. Type B’s are more Mediterranean or pesco vegetarian. B’s do well with dairy. Type B and AB have many odd issues with foods like chicken and corn. (hint, it’s the lectins).  Eat right for your blood type, is based on the evolution of our ancestors, where they lived and what they ate. If you like this idea, get a hold of it and learn more. You can try to eat according to your blood type. A food sensitivity test will also be helpful to guide your choices and heal your gut. 


Evidently, you name it, there is a diet for it. I’ve only mentioned a few of the more popular ones you might have heard about. I don’t know about you, but by the time I was done investigating so many different diets, most foods in some diet or another, had been eliminated. Goes to show there is no one right diet for everyone.  Then I asked myself… is there a diet with no food? Apparently yes, there is.  It is called fasting. The fasting diet. No shopping, cooking or meal prep required. You just don’t eat anything. First part sounds enticing. That saves a ton of time. But wait. Don’t we kind of need food? Ah. Back to the purpose of why we eat. It’s for nutrition and energy and building blocks of life-living and life-giving requirements. 

[1] Nelms, M., Sucher, K., Lacey, K. (2016). Nutrition Therapy & Pathophysiology; 3rd edition Centage Learning

[2] Abdul Rahim, M., Chilloux, J., Martinez-Gili, L., Neves, A. L., Myridakis, A., Gooderham, N., & Dumas, M. E. (2019). Diet-induced metabolic changes of the human gut microbiome: importance of short-chain fatty acids, methylamines and indoles. Acta diabetologica56(5), 493–500.

[3] Cabrera-Mulero, A., Tinahones, A., Bandera, B., Moreno-Indias, I., Macías-González, M., & Tinahones, F. J. (2019). Keto microbiota: A powerful contributor to host disease recovery. Reviews in endocrine & metabolic disorders20(4), 415–425.

[4] Piljac Zegarac, J. The Low-FODMAP Diet for IBS: What You Need to Know,   Accessed Aug 23, 2019