5 popular diets, explained

5 Popular Diets, Explained

Oct 03, 2018

Stat: In a nationally representative sample of Canadian adults "64.3% had made an effort to change their eating habits over the past two months".

For most of us, getting our diets right is an ongoing challenge. With so many different methods and philosophies around, deciphering which regimen is best suited for you can be a challenge. Whether it be to gain strength, lose weight or just feel better overall, the reasons behind tailoring your food choices are as countless as the options. To help you decide, we’ve dug into some of this year’s most popular diets and how they can help you achieve your goals.

Carb Cycling

What is it?
This diet consists of alternating between high and low carb days. This means cycling between meals that are primarily made up of mainly carbohydrates, and ones that are made up of everything but. Intervals range from daily to monthly, and no calorie counting is required.

What does it do?
Carb cycling is designed to help you shed pounds while retaining lean muscle tissue. Glycogen, the glucose your body creates with carbohydrates, is what your body typically uses for energy, but since low carb diets deplete these stores, your body is forced to resort to fat for fuel. On carb peaks, cycling helps your body restore these levels.

Things you should keep in mind
This diet requires a lot of planning, so meals should be meticulously plotted to ensure optimal results. Additionally, since extreme dieting can be difficult to sustain, one of the side effects is weight gain and fluctuation, which may work directly against your goals. In addition, while this is a common diet for athletes, restricting carbs, even with adequate protein, can result in decreased muscle . It is best to work with a personal trainer and a nutritionist to configure the right carb cycling plan for you. Finally, this diet also presents some capacity for deficiency in omega-3s on high carb/low fat days and fibre and B vitamins on days you are consuming more high fat/low carb foods.

The Ketogenic (or Keto) Diet

What is it? 
The ketogenic diet is a low-carb, high-fat regimen that requires you to eat “no more than 50g of carbohydrates per day or 10% of daily energy from carbohydrates” . The intention here is to get most of your daily calories from protein and fat, submitting your body into ‘ketosis’.

What is ketosis?
Ketosis a normal metabolic process that kicks in when your body isn’t getting enough carbs. This process drives your system to turn fat to fuel, forming what are called “ketones”. These are water-soluble molecules that your body produces when it isn’t receiving the insulin it needs to turn sugar into energy.

What's happening on the inside?
After roughly four days of having less than 50g of carbs per day, the body shifts into ketosis, burning fat for energy in lieu of sugar. For this reason, fats are a big part of this diet. This means you’ll need to stock up on foods high in healthy fats like avocados, cheese or eggs, and have license to indulge in some of your illicit favourites (see: bacon). Just make sure to keep yourself within the organic, nitrate-free options.

What you should be looking out for
Given its limitations, this diet could leave you with potential deficiencies in essential nutrients like fibre, vitamins, and minerals. This places you in particular danger for lack of vitamin A, E and magnesium . Additionally, since you are probably used to eating more (and with more variety), falling into ketosis may lead you to experience nausea, headaches, fatigue and “fasting breath” . If your goal is weight loss, try slowly decreasing carbohydrates and increasing fats over 2 weeks to avoid these side effects.

Intermittent Fasting

What is it?
Intermittent fasting is an alternative spin on traditional fasting, asking you to alternate your regular meal times. This means cycling between fasting and eating, so no changes are made to the types or amounts of foods eaten, but solely on the time spent between meals. Meals are typically eaten between noon and 8PM, or between 7AM and 3PM. Fun fact: since it falls straight into alignment with your circadian rhythm, research shows that eating meals between 7AM-3PM actually helps to improves insulin sensitivity and lower blood pressure.

What's happening on the inside?
As we mentioned, once your glucose stores have been used up, your body turns to fat for energy. When you fast intermittently, your body’s insulin levels drop and your growth hormone’s blood levels can increase as much as 5-fold. This makes things like fat burning and muscle gain much more common. What’s more? Intermittent fasting has been shown to relieve both oxidative stress and inflammation.

What you should know
Some people may have low blood sugar, leading to low energy and dizziness while fasting. Water-soluble vitamins, like vitamin C and B, are not stored by the body so drink plenty of water and include a vitamin C and B-complex supplement during your fasting period.

Military Diet

What is it?
Also known as the 3 day diet, the “military diet” is a strict, low-calorie regimen that requires you to consume less than 1,000 calories per day. Adhering to a strict, pre-determined meal plan is pivotal to the success of this diet.

Sample meal plan:

  • Breakfast : 5 saltine crackers, 1 slice of cheddar cheese & 1 small apple
  • Lunch: 1 hard-boiled egg & 1 slice of toast
  • Dinner: 1 cup of tuna, 1/2 banana & 1 cup of vanilla ice cream

What's happening on the inside?
This diet is intended to send your body into a caloric deficit, which is described as the shortage of calories consumed relative to the calories necessary to maintain your current body weight. With the average, low-activity Canadian requiring anywhere between 2,100 and 2,700* calories a day, consuming less than 1,000 is a surefire way to send your stores into arrears. Since a deficit is created when you burn more than you consume, this diet may accomplish that.

What you should know
1,000 calories are far below Health Canada’s recommended amount of calories for the average adult, and can be very difficult to sustain. Maintaining a diet of this nature for an extended period of time may promote malnutrition and unhealthy eating habits, negatively affecting your health overall. Moreover, this diet presents a lack of diversity, limiting your intake of vital nutritional groups like fibre-packed whole grains, energy-boosting B-vitamins and countless other need-on-a-daily-basis nutrients.

Paleolithic (or Caveman) Diet

What is it ?
The paleo diet mimics those of hunter-gatherers of times past, requiring you to eat only what you can catch. This includes things like meat, fish, fruits and vegetables, and healthy fats. No processed foods are consumed, and agricultural foods such as grains, dairy, and legumes like beans are to be avoided.

What does this mean for your body?
Sticking to paleo means you’ll avoid additives, refined sugars, and a lot of the foods that are making us sick these days. You’ll also be receiving the anti-inflammatory benefits that come from ingesting more from plants and nuts.

What to watch out for
With a strong emphasis on meat and fish, this diet isn’t one that can be adopted by vegetarians or vegans. It also presents possible deficiencies in B-vitamins, calcium, as well as vitamin D and omega-3 if you aren’t eating any fish or nuts.

Our verdict:
While many of these diets may serve as good short-term alternatives to the conventional way of eating, the old adage rings totally true: diets aren’t fads, they’re lifestyles. The most proven way to feel your best is by creating and maintaining a healthy lifestyle that suits your pace. Before starting any new diet, it is best to speak to a health care practitioner, particularly if you have a health condition, to ensure it is right for you.


  • Schermel A, et al. (2014) Canadians' Perceptions of Food, Diet, and Health - A National Survey. PLoS ONE 9(1): e86000.
  • Amidor T. (2018). Ask the expert: Carb Cycling for Weight Loss. Today's Dietitian. Vol 20 (7).10.
  • Bueno NB et al. (2013). Very-low carbohydrate ketogenic diet v. low-fat diet for long term weight loss: a meta-analysis of randomized controlled trials. Br J Nutr. Oct;110(7):1178-87.
  • Christodoulides SS et al. (2012). The effect of the classical and medium chain triglyceride ketogenic diet on vitamin and mineral levels. J Hum Nutr Diet. Feb;25(1):16-26.
  • Mayo Clinic. (2017). Low-carb diet: Can it help you lose weight?
  • Military Diet Plan 3 Day Military Diet Menu Plan.
  • Mani, K., Javaheri, A., & Diwan, A. (2018). Lysosomes Mediate Benefits of Intermittent Fasting in Cardiometabolic Disease: The Janitor Is the Undercover Boss. Comprehensive Physiology, 1639-1667. doi:10.1002/cphy.c180005
  • Health Canada (2011, November 08). Estimated Energy Requirements.
  • Rosenbloom, C. (2009, June 30). Calories, protein, carbohydrates and fat: How much do I need?

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