Ketogenic Diet – Weight loss or Waste of Time?

Writing by Ally Choo, Grace Tan, Abby Hsiao (UBC Dietetic Students)

What is the Ketogenic Diet?

The ketogenic diet first hit the scene back in the 1920’s when it was used as a possible treatment for epileptic individuals. Nowadays, you’ll probably hear it circulating mainstream media as a cure-all, weight loss remedy. So how exactly does it work? The goal is to force your body into a state of ketosis. Ketosis occurs when you deprive your body of glucose, therefore forcing your liver to convert fat stores and some amino acids into ketones to fuel the body. If the big guy upstairs (the brain) runs out of glucose, ketones are the next best thing. In order to achieve ketosis, your diet must obtain 80% of its calories from fat, while consuming 15% of its calories from protein, and 5% from carbohydrates (about 30 – 50 g of carbohydrates a day). To put this into perspective, 50 g of carbohydrates is only about 1 cup of cooked brown rice. Before you start running from every carb in sight, let’s see if this diet has any evidence to back up those weight loss claims. Let’s take a look at the evidence.

The Pros:

Here’s the good news: the evidence is supportive of the ketogenic diet for weight loss in the short term (up to six months). The average amount of weight lost in that time frame is 2 to 4 kg – this is particularly true for individuals with a BMI over 25. Since the diet involves cutting out foods high in carbs, it implies omitting sugary foods such as soda, candy, and other energy-dense options from the diet. The diet also consists of mostly fat, which triggers the release of CCK, a hormone that contributes to satiety. As a result, it keeps you full for longer while your body utilizes that fat for energy rather than storing it.

And the Cons..

Sounds promising, right? Well here’s the main problem: there aren’t many studies out there that focus on the long-term implications of low carb (<5% of total calories) and high fat (80% of total calories) diets. It is not an easy diet to follow – it requires a lot of effort to plan, which could make it hard to sustain. This could mean that you can regain the weight back once you stop the diet. You might also be wondering if it is possible for a diet that omits an entire food group to be nutritionally adequate. Due to the extreme carbohydrate restriction, key nutrients such as B-vitamins, and calcium may be limited since major sources of these nutrients are grains and milk products respectively, both of which provide notable amounts of carbs. This diet could also be potentially low in fibre and certain essential micronutrients such as sodium and potassium. Also, If you’re looking for a diet to fuel your workouts, going low-carb may not be the solution since fat doesn’t generate energy fast enough for moderate-high intensity exercises.

Bottom Line

The evidence we have now shows that the ketogenic diet has promising effects on weight loss. We know that more long-term research is needed but aside from the evidence, it’s ultimately up to you to decide if this is the best way to go about managing your weight. This diet can be nutritionally adequate if it is done properly, so it could work for those who are more organized with their meal planning. For example, B vitamins are rich in grain products, but they are also found in all food groups. As for calcium, low-carb foods such as cheese, fish, and leafy greens are great options. On the other hand, the strictness and rigidity can make it a poor fit for others.

So if you are considering it, we’ll leave it to you to decide but we will say this, the best diet should be one that contributes to your happiness and overall well-being, lets you enjoy food, and is something that you can stick to for the long haul! As always, we’re here to help and answer any of your questions.


3 thoughts on “Ketogenic Diet – Weight loss or Waste of Time?

  1. alexandrawhite12 says:

    I have been doing the Keto diet for a bit now, not entirely strictly seeing as I dont believe in life without vegetables. The Keto diet you refer to is more like the medical keto than the nutritional keto. I keep my macros at <20% of total calories coming from carbs. This has resulted in essentially eating healthier but maintaining ketosis. Lots of fresh veggies, good natural sources of fat and protein and some light to moderate exercise. I don't know that anyone really does the medical keto thing anymore. I would be interested in hearing your take on a more nutritionally minded Keto diet.


    • whitneyhussain says:

      Hi Alexandra,

      Great question. The ketogenic diet actually requires this strict reduction in carbohydrates to maintain ketosis – if you’re eating more than the recommended amount in the article, your body actually isn’t in ketosis (keeping in mind the diet recommends being in a state of ketosis rather than a state of ketoacidosis). The diet you’re maintaining seems to be a balanced diet rich in nutrient dense foods which is great, but you’re likely not in ketosis based on the guidelines. Most individuals wanting to maintain the ketogenic diet referred to in the article are keeping their carbohydrate consumption very low (lower than <20% total calories from carbs) to reap the "benefits" of the diet.

      It's possible to maintain nutrition adequacy with the ketogenic diet (if done correctly) but it's also difficult for some of us dietitians to fully recommend it since there isn't research out there (yet!) to assess the long term impact of the diet.



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