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The Benefits and Drawbacks of the Keto Diet
What is the Keto Diet?
A keto diet (ketogenic) is a very high-fat diet, moderate to low protein and very low in carbohydrate, which causes a shift in primary metabolic fuel source from carbohydrates to fats. It also alters fat metabolism so the body produces compounds known as ketone bodies in the liver.
These compounds include acetone, aceto-acetate & beta-hydroxy-buterate. These ketones can be used as energy in tissue like skeletal muscle and more importantly, brain. If you’re looking for a more flexible approach then start with the macro calculator to begin losing fat.
Under normal conditions, the brain exclusively uses glucose for energy, but in a ketogenic state, the brain will shift to using ketones as a fuel source in order to spare blood glucose for essential tasks such as red blood cell metabolism (red blood cells can only use glucose as fuel since they lack mitochondria).
Keep in mind that even with zero carbohydrate intake, the liver can produce about 120g of glucose per day in a process called gluconeogenesis (GNG) for essential tasks from substrates like amino acids and other gluconeogenic metabolites.
Where did the Keto Diet Start?
The keto diet gained most of its attention for its role in the nutritional management of epilepsy and Alzheimers. More recently, science has shown positive clinical outcomes for a number of types of cancers through its ability to minimize tumor growth. In the case of all three of these diseases, ketones are therapeutic through providing an alternative substrate to glucose.
Ketogenic diets have also recently moved into the fitness & bodybuilding industry as a dietary method to improve body composition and reduce body fat.
Why are Carbohydrates Viewed as the Bad Guys?
Carbohydrates are often viewed as bad for body composition due to the fact that they increase insulin secretion. Insulin is a hormone that is released when blood glucose rises and shuttles glucose into various tissues including muscle and fat.
Due to this, insulin is considered a storage hormone and thus many people have made recommendations to avoid carbohydrates at all costs.
Carbohydrates and Insulin: Primary Cause of Body Fat Gain?
Since carbohydrates do increase insulin and insulin is a storage hormone many people have made large leaps of logic to point the finger at carbohydrates as the primary cause of fat gain and obesity as opposed to overall caloric intake. They also point out that in a keto diet, carbohydrates are not being used as fuel hardly at all whereas fats become the primary fuel.
Their logic is, eat more fat, burn more fat. While that is true to a certain extent, it’s not quite that simple.
When calories and protein are equal, a keto diet does NOT seem to offer any additional fat loss benefit compared to an equal calorie, equal protein non-keto diet according to a study published in 2006 in the American Journal of Clinical Nutrition from Arizona State University.
These individuals miss the fact that by limiting carbohydrate to very low levels in the diet, you are typically going to restrict calories as well.
In fact, many people have become so passionate about low-carb lifestyles that they become keto-zealots rather than caring about the science of what actually makes a fat loss diet successful.
This debate is a major factor why the keto diet is such a hot topic right now, but are they really inherently superior for fat loss?
Why the Keto Diet isn’t Superior for Fat Loss
There are several studies that keto-zealots often point to in order to support claims of a keto diet being superior for loss. For example, a recent meta-analysis published in 2013, compared very low-calorie ketogenic diets (VLCKD) to low-fat diets with a minimum of 12 months of follow-up.
They found that individuals who were assigned to the VLCKD were able to achieve greater weight loss than participants in the low-fat groups.
What this study doesn’t consider is that the research studies selected for inclusion in this analysis did not equate for protein and in some cases even overall calorie intake.
So it’s likely greater weight loss was achieved in VLCKD by default since we know a keto diet can be more satiating and often people consume lower calories than in low-fat high carbohydrate diets. These studies also did not control for protein intake which is often higher for a keto diet vs. a low fat, high carbohydrate diet.
So what does the science say? When calories and protein are equal, a keto diet does NOT seem to offer any additional fat loss benefit compared to an equal calorie, equal protein non-keto diet according to a study published in 2006 in the American Journal of Clinical Nutrition from Arizona State University.
In this highly controlled study, both groups lost an almost identical amount of weight and body fat. This says that for fat loss, you can do whatever your preference is.
What About the Health Benefits of a Keto Diet?
There is data to support a benefit of a keto diet in a number of medical conditions such as epilepsy, Alzheimer’s, cancer, and type 2 diabetes.
In these conditions, providing an alternative fuel source instead of carbohydrate seems to have a therapeutic effect. In the case of type 2 diabetes, using ketones as fuel instead of glucose can help lower blood glucose levels.
It is important to point out however, that type 2 diabetes also improves during any form of caloric restriction and it is likely that a keto diet is not unique in that aspect, rather it is causing a caloric deficit by severely restricting carbohydrate intake. We have helped numerous clients lose fat while on a moderate carb intake in a caloric deficit.
Keto diets are also found to possibly be helpful for a number of types of cancers, specifically glucose obligate cancer types. Meaning they can only grow with glucose present as the tumors use it as exclusive fuel.
Thus by limiting carbohydrate intake and forcing our bodies to use fats and ketone bodies instead of carbohydrate, can have a therapeutic effect by essentially ‘starving’ these tumors.
Please keep in mind this is not a ‘cure’ for cancer and some cancers are not glucose obligate users. If you have cancer you should ALWAYS follow your oncologist’s recommendations for your specific disease.
Some studies have reported less hunger when following a keto diet and this is believed to be linked to fats being more satiating resulting from slower digestion and extended feelings of fullness.
Currently, the most popular form of keto is a modified keto diet…
A number of studies reported decreased triglycerides, diastolic blood pressure and greater increases in HDL in the keto diet groups compared to a low-fat diet.
However, we need to consider that most of these studies failed to equate for both calories and protein, and it is likely that if similar weight loss was achieved, these health outcomes would look similar regardless of the diet used. This is supported by the Johnston study from Arizona state which saw similar outcomes when calories and protein were equated.
Common Mistakes of Ketogenic Diets
The major mistake I see for people on a keto diet is they do not adhere to the correct ratios of macronutrients necessary to ensure ketone production. For example, adherence to low carbohydrate is usually met by most. However, the ratio of protein to fat is often too high.
On a traditional keto diet, carbohydrate intake is usually about 5-10% of total caloric intake, protein is 10-15%, and fats are around 80%.
Currently, the most popular form of keto is a modified keto diet which puts carbohydrate intake around 5-10% of total caloric intake, protein at no more than 20-25% of total energy intake and fats should make up the majority of total calories at approximately 70% of calories.
Often we see clients that aren’t following either of these splits while attempting to be on a keto diet. This, of course, hinders their results.
Why is Having Too Much Protein a Problem?
In a carbohydrate-restricted state, the body calls upon its secondary energy sources, namely fats and proteins in order to function. In a carbohydrate-restricted state, protein is converted to glucose through the process known as gluconeogenesis in the liver as described previously.
This is why it is important to ensure your protein is not providing greater than 20-25% of your total caloric intake while following a keto diet, as too much protein results in glucose production and remains the primary energy source, as opposed to fats or ketone bodies.
When it comes to overall body composition and fat loss, the keto diet isn’t better than carbohydrate containing dietary interventions when both calories and protein are equated.
The idea of being able to eat plenty of high-fat foods at every meal may sound highly appealing to some but doesn’t come without nutritional consequences. Eliminating carbohydrates means like any diet plan that restricts whole food groups, makes it far more difficult to meet daily micronutrient requirements, in particular B- vitamins.
If you prefer high-fat foods in preference to carbohydrate containing food products, particularly during a phase of calorie deficit, and you find it easier to adhere to this way. Then, by all means, attempt a keto diet.
It’s important to make sure you consume a wide variety of fresh vegetables, as these are essential for their rich source of fiber, vitamins and minerals, antioxidants and other important micronutrients.
In any case, I strongly recommend taking a multivitamin as well as an iron supplement, specifically for women, or males on low caloric intakes, since it is difficult to consume a sufficient iron, and reasonable to ask without essentially all protein sources being provided by lean red meat.
Any nutrition diet plan that sees you in a caloric deficit is going to result in fat loss. If you prefer high-fat foods in preference to carbohydrate-containing food products, particularly during a phase of calorie deficit, and you find it easier to adhere to this way. Then, by all means, attempt a keto diet.
Yet, be sure that you can make it a lifestyle. There is little benefit to following a diet plan that is not maintainable long term. Many people lose weight on a keto diet, only to pile the pounds back on after carbohydrates are reintroduced.
If you feel as though you want to include carbohydrates within your diet, then have us build you a Macro Blueprint. As outlined above, the most important factor while on a diet plan is restricting calories. This can be achieved with a proper split including carbs.
Need Help with Preparing a Keto Diet?
Foods High in Fat
- Regular Cream Cheese
- Full Fat Tasty Cheese
- Camembert / Brie
- Cooking Cream
- Thickened Cream
Meat & Protein Sources
- Bacon (full fat)
- Chorizo sausage
- Meat products with visible fats
- Pork Belly
- Egg Yolks
- Whole Eggs
Oils and Fats
- All varieties
- i.e. Coconut oil, canola, olive, peanut oil, sesame oil.
- Coconut cream
- Coconut milk
- Coconut flakes
- Desiccated coconut
Fruit & Nuts
- Avocado spread
- Brazil nuts
- Dark Chocolate Unsweetened
- Cacao (unsweetened chocolate)
- Natural Peanut Butter
- Cashew/Macadamia Spreads
The following vegetables can be eaten relatively freely due to their low carbohydrate content, high fiber, and nutritional value.
- Cruciferous Vegetables such as Broccoli, Cauliflower, Cabbage, and Brussels Sprout
- Leafy Greens such as Spinach, Chard, Lettuce
- Lemons and Limes
The Following Fruit & Vegetables can be Eaten in Moderation
(i.e. makeup about 50-100g per day as these are slightly higher in carbohydrate than the above but are important to include due to their equally valuable fiber content and high nutritional value.)
- Capsicum/bell peppers
Foods to Avoid When Following a Keto Diet
- Wheat and products of (i.e. bread, breakfast cereals, grains, crackers, biscuits)
- Potato and products of (i.e. potato chips, hot chips)
- Corn and products of (i.e. corn chips, corn cakes, corn tortillas, corn dips)
- Rice and products of (i.e. rice pudding, rice crackers, rice cakes)
- All baked products such as muffins, bread, slices, biscuits, pancakes, croissants etc.
- Fast Food such as Pizza, French Fries, and Ice Cream
- Regular flavored yogurt (natural yogurt is suitable but pay attention to portion size)
- Milk products (milk alternatives such as unsweetened soy, coconut milk, and almond milk are suitable)
- Fruit, in general, should be consumed with care, pay attention to portion size if you wish to adhere to your daily carbohydrate targets. For example, banana & mango, both high carbohydrate could very easily take you over in just one serve.
- Sugar, Honey, Maple Syrup, Corn Syrup (natural & artificial sweeteners such as stevia, aspartame, and sucralose are suitable for sugar substitute)
Ultimately, we understand that there’s no magical diet and that some prefer to eat more fat while dieting. We have dealt with over 15k clients, many of which have medical restrictions and require different parameters while in a caloric restricted state. No matter what your limitations, preferences or needs are while on a diet plan. We can build you a Macro Blueprint that will help you lose unwanted fat.