Unless you’ve been under a rock recently, you’ve heard the buzz about the ketogenic diet (or keto).  Everybody is confirming miraculous weight loss results and increased brain power.  But what’s the deal with it and is it really all that we think it is?

What is the Ketogenic Diet?

The keto diet is a diet that severely restricts the intake of carbohydrates and instead relies heavily on the consumption of protein and fat for the bodies energy demands.  The process that follows this dietary change is called ketosis, and it’s the state in which your body is using fat stores and dietary fat as it’s primary source of fuel.

A typical ketogenic diet will have a macronutrient profile like this:

  • Carbohydrates – 5-10% of daily calories, though usually 20 grams or less
  • Proteins – 15-30% of daily calories
  • Fats – 60-75% of daily calories

The benefits

The claimed benefits of the ketogenic diet include:

  • Improved cognitive function / memory
  • Aids in weight loss, decreases appetite
  • Improved HDL
  • Reduces inflammation
  • Reduces risk of cancer
  • Increases insulin sensitivity and decreases blood glucose
  • It’s easier to stick to than other diets**

**This can be true for some because the increased protein consumption aids in satiety, or satisfaction and feeling full after meals, while for some it feels overly restrictive and can lead to rebound.

The negatives

Although there seems to be a lot of upside to keto, specifically in terms of treatment of common diseases, there are also a lot of adverse effects of the diet.  Adverse effects are different from side effects in that they are not simply unwanted but are rather dangerous and can be life-threatening.

Here’s a good list of the adverse effects of the ketogenic diet as documented by research (via Dr. Sarah Ballantyne, PhD):

  • Gastrointestinal disturbances (diarrhea, vomiting, nausea, constipation, GER)
  • Inflammation risk
  • Thinning hair/hair loss
  • Kidney stones
  • Muscle cramps or weakness
  • Hypoglycemia
  • Low platelet count
  • Impaired concentration/cognition
  • Impaired mood
  • Renal tubular acidosis
  • Nutrient deficiency
  • Disordered mineral metabolism
  • Poor growth in children
  • Skeletal fracture
  • Osteopenia/osteoporosis – due to increased acidity of the blood from ketones
  • Increased bruising
  • Sepsis, infection, bacteria overgrowth
  • Pneumonia
  • Acute pancreatitis
  • Long QT intervals
  • Cardiomyopathy
  • Shift towards atherogenic lipid profiles (including hypercholesterolemia and hypertriglyceridemia)
  • Heart arrhythmia
  • Myocardial infarction,
  • Menstrual irregularities and amenorrhea
  • Death

How does keto work for weight loss?

In the first few days of going keto, your body will continue to use your leftover glycogen stores and any incoming carbohydrates for energy, specifically for your brain.  But once those run out, the body will need to produce ketone bodies if it wants to supply any energy to the brain.

These ketone bodies come from fat cells and are used by the body as energy in the absence of carbohydrates.

This change in primary energy source results in the body being better able to use fats for energy, including dietary fats.

With respect to weight loss, the ketogenic diet is extremely effective because it essentially eliminates 50% of your diet (carbohydrate consumption for the average American).

In addition to eliminating calories, it increases your reliance on protein, which increases your daily caloric expenditure through the thermic effect of feeding (calories burned through digestion).

The reality is that the ketogenic diet works the exact same way that all other diets work: by creating a caloric deficit.  It just does it by removing an entire macronutrient group from your diet (read: carbohydrates).

Is it good for me?

The biggest question about the ketogenic diet is whether or not it’s healthy.  As a whole, our society is still very skeptical of dietary fat and with good cause.

The truth is, the ketogenic diet hasn’t been studied all that much, and the studies that claim to be long-term really only studied participants for less than a year.  So we have no clue about the long-term effects of the diet, specifically with relation to heart disease.

Some studies have found that the ketogenic diet is effective over the short-term, but over longer periods of time it holds no advantage to other diets with respect to weight loss (1).

In a study done on children, researchers found that after 6 months of a ketogenic diet, the subjects experienced significantly increased plasma levels of LDL’s and VLDL’s (bad cholesterol) while seeing a decrease in HDL (good cholesterol) (2).

However, one study found that participants experienced increased levels of LDL’s when on a modified Atkins Diet (3) while another found that HDL increased while LDL decreased (4).

Summary

  • The ketogenic has been proven to be very effective in weight management, specifically in the short term.  Over the long-run it doesn’t seem to have any superior effect when compared to other diets and it works in the same way other diets work.
  • The risks of the ketogenic diet are relatively unknown as it hasn’t been studied thoroughly, but might include complications in blood lipid profiles, the most prominent predictor of heart disease.
  • The ketogenic diet is very restrictive and can lead to rebound over the long run in terms of weight management.
  • It has medical potential for the purposes of treating diabetes, cancer, seizures, and most likely a slew of other medical conditions.

All in all, keto has a ton of promise in terms of the health benefits it might provide, but currently the research is too conflicting and poorly executed for us to be positive about the effects of such a diet.

Until then, it would be wise to transition to keto with the help of a medical professional if you feel that you would benefit from a diet like this one, especially if your blood work has produced results that are outside the normal range for any of the biomarkers.