Five Fad Diets Demystified

It’s hard to believe we’re only (already ?!) two months into 2019 and there are already articles about the best/trendiest/most popular diets of the year.  Of course, these kinds of lists come out every year, and every year people jump on (and off) them.

Do any of these diets actually “work?”  Well, I guess that depends on how you define success.  Arguably, no, not in the long-term anyway, or else we wouldn’t be perpetuating a multi-billion dollar global diet industry.  But there’s always going to be someone, from an instagram “celebrity” to your brother-in-law’s uncle who SWEARS by XYZ diet, and is so fervent in their zeal that you start thinking that maybe, just maybe, it’s finally the diet FOR YOU, and maybe you should check it out.

Out of the “oodles” (that’s the scientific term) of diets out there, certain ones seem to surface and gain more vocal adherents more often than others.  This week, my Instagram video series and Facebook posts are looking at keto, paleo, plant-based eating, tracking macros and Intuitive Eating approaches.  I’ll give you the low-down on the WHAT of these diets, the pros, the cons and my verdict.

Let’s dive in for diet de-mystification (also a technical term, right?).


The keto diet this seems to be an approach to eating on everyone’s radar these days. “Keto” is short for both “ketosis” and “ketogenesis” – they are related but not the same.  And is keto the same as LCHF (low-carb high-fat)?  Not necessarily.  Keto certainly is a low (extremely low) carb way of eating, and yes, it’s high in fat as well.  But not all LCHF diets are sufficiently low in carbohydrates and/or high enough in fat to cause the body to be “in ketosis.”  What’s that?  Read on!

Our bodies’ preferred source of energy is carbohydrates, but we’re so amazingly adaptable that we can also generate energy in the absence of carbohydrates. When we remove dietary carbohydrates, the body will use fats to create ketone bodies (this creation is ketogenesis, where “genesis” is “beginning” or “creation”). Then our bodies use those ketone bodies to create energy in our cells, to fuel all of our bodies’ processes (ketosis – the process of breaking down ketones for energy).  Eating in this way is called nutritional ketosis.

How do you know if you’re “in ketosis”?  Blood or urine test strips to detect the presence of ketone bodies are often regarded as the “gold standard” in assessing ketosis.  Keto lovers will often also say that they just “know” when they’re in ketosis or if they’ve been “kicked out” of ketosis (usually by making a high-carbohydrate food choice).  Another tell-tale sign can be the odour of breath or urine; the presence of acetone production is a byproduct of ketosis and this will cause a “nail polish remover” smell.

If there are still carbohydrates in our system, our body will preferentially use those first (it’s a more efficient energy system).  This is why I say that not all low-carb diets are sufficiently low enough in carbs to cause ketosis.  Also, dietary fat intake has to be high enough to supply the body with energy.

Without enough fuel coming in, the body will actually start to break down lean muscle tissue to preserve fat because lean muscle tissue is metabolically “expensive” – it burns more calories at rest than other bodily tissues.  If the body senses that it’s in a famine (due to dietary restriction), it’s going to jettison that lean muscle tissue so that it doesn’t need as many calories coming in.  So, you’re eating less, and then you actually need less, which requires you to reduce intake even further to see further losses, and you end up with less muscle mass still.  This reduced metabolism or metabolic rate is the so-called starvation effect.  If you try to go back to eating “normally” you’ll find that you actually gain weight because you have less muscle mass than when you started and you don’t need as much food.

Does this diet “work”? Some adherents find that because they prioritize fats and proteins, which are more satiating than carbohydrates, they have a sense of feeling full while ingesting fewer calories. This style of eating also naturally eliminates many processed snack foods because they are high in carbohydrates (chips, cookies, crackers, cake, etc.). This latter effect is not limited to the keto diet, of course.  Simply giving up processed snack foods with no other changes to the diet can also result in weight loss, and you can still enjoy a banana or pasta night.

Pros: removes many processed foods with “empty” calories. Can increase satiety. Provides medical benefits for certain subsets of the population.

Cons: can be overly restrictive and create disordered eating patterns. Often not sustainable in the long term. Harder to accommodate in some social settings, leading to isolation. Can create unreasonable fear of healthful foods like starchy vegetables or fruit and may cause micronutrient deficiencies.

Verdict: like any approach to eating, it can be a great long-term sustainable strategy for some people and not for others.  I would argue that the “some people” for whom it works is a very, very small percentage of the general population and that there are better, more sustainable and balanced ways to achieve fat loss.


This approach to eating is based on our best guess as to what Paleolithic man (or woman) ate.  (By the way, this of course is a complete crapshoot – yes, that’s the scientific term – because none of us was around then and we don’t have any written records to know for sure what was on the menu.  We can of course, make some educated guesses by studying the stomach contents of mummified remains from this era, or looking at clues about general lifestyle patterns).  The argument is that although our lifestyles have evolved since then, our bodies haven’t really kept pace and are still optimally served by eating the same foods available to us as then.

Since the Paleolithic Era preceded the advent of modern agriculture and the domestication of animals, these means no grains and no dairy. There are also no processed/refined sweeteners, and legumes are out as well. Alcohol is debatable; it gets a pass in some paleo circles if it comes from potatoes and not grains.

What’s left? Meat (including fish and fowl), nuts and seeds and fruit and vegetables.  Or sure, there are lots of “paleo-friendly” re-creations of our favourite foods (paleo coffee cake, anyone?) using these ingredients as a base, but super strict Paleo protocols would take these off the table, too.

Does it “work”? For some people, this style of eating naturally causes their energy balance to reduce calories in.  They may also discover previously unknown food sensitivities especially if they periodically test a “reintroduction protocol” to carefully monitor the effects of eating a non-Paleo food.

A poor reaction to a certain food is not necessarily a smoking gun, though.  We can’t take full credit for our digestion on our own.  Our “gut flora” is populated with billions of handy bacteria and enzymes that can help us digest foods that would otherwise be impossible or uncomfortable to digest.  It makes sense that if we remove a certain food or food group for a period of time, our gut would re-colonize and the bacteria and enzymes that previously helped us digest the food would no longer be present, or in much lower amounts because they weren’t needed while the food was banished.  Eating small quantities of the food over time could restore these helpers and the symptoms would peter out.

For others, it doesn’t “work” – they continue to eat to appetite or even overeat because of a mindset that since it’s “Paleo-approved” it must be okay in unlimited amounts.  Paleo or not, nuts and seeds add up fast in terms of calories!  Finally, the mental restriction of banished food groups makes it a poor long term strategy if it causes followers to fear or demonize certain foods.

Pros: removes many hyper-palatable, processed foods and emphasizes natural, whole food choices, which can naturally correct micro-nutrient deficiencies and may also cause people to feel fuller despite ingesting fewer calories because of the increased protein and fiber content of their diet.  In line with my comments on the keto diet, simply giving up processed snack foods with no other changes to the diet can also result in weight loss, and you can still enjoy a bowl of oatmeal or a spoonful of peanut butter (maybe even together!).

Cons: has so many restrictions that it can lead to disordered eating patterns and/or is not sustainable in the long term.

Verdict: like any approach to eating, it can be a great long-term sustainable strategy for some people and not for others.  Making a move to include more whole, minimally-processed foods is almost always a great choice.  The best dietary strategies emphasize what you are ADDING, not what you are taking away.

Plant-based eating

This approach to eating also seems to be getting a lot of press lately. It is definitely part of a vegan lifestyle, but not all plant-based eaters are vegans. Vegans will eschew ALL animal products and their byproducts and derivatives, right down to beeswax in lip balms, gelatin in candies or fabrics like wool or leather because they are animal-based. This usually comes down to ethical or moral arguments or philosophies.

Plant-based eating may be part of an overall vegan lifestyle or it may be stand-alone as a way to reduce but not completely eliminate consumption of animal-based products. It might be a way of addressing dietary intolerances or simply preferences – some people don’t like the taste or texture of meat.

Does this diet “work”? Again, some plant-based eaters find that this approach to eating naturally manages their energy balance because they are eating more vegetables and fruit and the high water and fiber content keeps them feeling full. On the other hand, others feel less full because they have reduced or eliminated consumption of animal protein sources that are more satiating. And there are many vegetarian or vegan foods that are still highly processed, high in calories and minimally nutritious (potato chips or vegan cookies, as an example).

Pros: can increase consumption of vegetables and fruit, and can have positive environmental impacts as commercial meat production is resource-intensive.

Cons: must be carefully considered to get adequate protein and key nutrients (iron and B12 often need to be supplemented).

Verdict: like any approach to eating, it can be a great long-term sustainable strategy for some people and not for others.  I believe that human beings are biologically omnivorous (eating both plants and meat).  Yes, we can choose to rise above our biology (take monogamy, for example), but let’s keep in mind that a moral or ethical choice about our own approach to eating doesn’t make it the “best” for others.

Tracking macros

“Macros” is short for macro-nutrients, the building blocks of food that are present in the largest amounts (“macro” meaning “large”) and supply energy to the body: carbohydrates, proteins and fat. By setting targets for each of these macro-nutrients, you naturally also indirectly set targets for calories.  You can learn more about tracking macros in this handy-dandy post I wrote, here.

Adherents believe that there are ideal proportions of certain macro-nutrients in either absolute or relative terms, and hitting those proportions can help with muscle gain (eating enough protein) and/or fat loss (eating enough but not too much carbs and fat).

Does this diet “work”? Since it puts a limit on energy intake, if it’s combined with increased energy output it can lead to fat/weight loss.

Pros: since all foods are considered in terms of their macro-nutrient breakdown, it can remove the idea of “good” or “bad” foods. It can also facilitate higher protein intake and it can encourage better quality food choices when dieters attempt to get the most food volume for their allotted macros (bang for your buck).

Cons: requires detailed tracking, weighing and measuring of food which can be overwhelming for some or less to obsessive or unsustainable behaviours in others (i.e. never eating out, never eating food prepared by others for fear of not knowing exact macro-nutrient breakdown).

Verdict: like any approach to eating, it can be a great long-term sustainable strategy for some people and not for others (yes, I am full on straight copy and pasting the verdict from one diet to the next).  Full disclosure: tracking macros has been my own personal favourite approach to eating in my health and fitness journey so far.  It has been especially helpful for me to overcome tendencies to “orthorexia” (an obsession with clean eating, i.e. rigid rules about only eating certain foods that are “clean” or “good”) and to give me a better sense of the amount of calories and nutrients supplied by various portion sizes of various foods, which in turn better helps me manage my energy balance, especially when I find that the demands and pace of my life keep me from fully tuning into my intuition (see next).

Intuitive Eating

Popularized under a book by the same name, this approach is about learning to really listen to and follow your body’s cues in terms of food and portion choices. It means learning how to know when you are truly physically hungry (and not bored, sad, happy, lonely, anxious, etc) and what nutrients/foods your body truly needs in that moment to address that physical hunger. It also means knowing how and when to stop eating.

While it sounds simple in theory, in practice there are a lot of elements of our modern lifestyles (processed, packaged food, artificial flavours, indoor lighting, extended hours, etc) that make it hard to recognize and follow these cues for hunger, fullness and food choice.

Again, full disclosure – this is an area where I admit I have not made it a priority yet in my journey to fully nail down these internal cues.  This is a conscious choice I have made for myself, and also one I can help clients make or not make for themselves.  I think it’s misguided and short-sighted to simply tell clients to “follow their body” without giving any advice or practical strategies to help them do that.  Generally, “following our body” in terms of eating has gotten us to the place where we have excess body fat to lose in the first place!

Does this diet “work”? With time and practice, adherents are often able to settle into a balanced approach to eating that serves them and their health well. However this can take education and patience as well as conscious practical strategies. Many find that without focus, it leads to unintentional weight gain.

Pros: it can lead to a better understanding of, and relationship with food and your body.

Cons: requires patience and education about and access to quality food choices.

Verdict: like any approach to eating, it can be a great long-term sustainable strategy for some people and not for others.

So, the question remains, what IS the best diet?  In all of the foregoing, I pointed out that there is NO one “best diet” for everyone.  The sooner you stop listening to people pushing (and spending money on) THEIR diet (especially when they’ve never met you, have never spoken to you, and know NOTHING about your background, training, lifestyle, food preferences or dieting history), and the sooner you start investing time (and maybe money) with qualified resources to help you find your OWN “best” diet, the better.

Have a fit day!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s