Top 10 Myths About the Ketogenic Diet

I'm often surprised by the uninformed and/or misinformed comments I hear and read about low-carb or ketogenic diets.  I want to address some of the things I hear most often.

1. It's a "fad diet"
A fad is, by definition, something new that won't last long.  The fact is, most if not all of mankind subsisted on this kind of diet up until the invention of agriculture.  This is where one of the popular low-carb diets, the so-called Paleo Diet, gets its name.  The basic principles were popularized by Dr. Atkins in his popular book on the subject in 1972.  38 years later, this "fad" is still only growing in popularity.


2. Ketosis is dangerous and harmful!
Ketosis, a benign and (I argue here) thoroughly beneficial metabolic state, is often confused with ketoacidosis, which is indeed dangerous.  It's most commonly suffered by alcoholics and type 1 diabetics, and is caused by the body's failure to properly regulate the production of ketones.


3. You won't get the nutrients you need
I've written an entire post on this subject. The short version is that you get far more of most vitamins and minerals on a proper ketogenic diet than on a typical diet. The main exception is vitamin C, which is only required in more than trace amounts if you're on a high-carb diet.


4. All that fat will give you heart disease
I've already written about this too, and I'll be doing it again. The subject is a bit complex, so I'll invite you to read the article I linked to, which itself links to a great deal of scholarly literature on the subject. Again, the short version is that the theory linking dietary fat intake to dangerous cholesterol levels and heart disease is not supported by the evidence. Here I'll just cite a single study on the matter.


5. It only works (for weight loss) because you eat fewer calories
Because high-fat diets satisfy hunger far better than low-fat diets, it's true that some ketogenic dieters consume fewer calories than they did before the diet. The entire theory behind low-carb dieting, however, is a rejection of the "energy balance" hypothesis. I deal with it fairly thoroughly here, and I'll be talking a lot about it in the future.


6. You'll feel terrible
For the first few days, this may be true as your body transitions to a completely new metabolic state. After that, if you feel fatigued or otherwise uncomfortable, you're doing it wrong. For example, some people make the mistake of trying to go low carb and low fat at the same time. That's essentially starvation. You should feel noticeably more energetic than before. Most people, myself included, say they feel better than ever before on a ketogenic diet.


7. You'll wreck your kidneys
People with very advanced kidney disease have trouble handling large amounts of dietary protein. I can only guess that this is the source of the misconception, not backed by any research anywhere, that a high-protein diet causes kidney disease. There may be an increased risk of kidney stones due to increased levels of uric acid in the blood, but that's easily avoided by drinking plenty of fluids, and if you want to be extra careful, taking potassium citrate supplements.


8. Maybe it's good for some quick weight loss, but it's dangerous in the long term
At this point, there's so much FUD surrounding the diet that few researchers are willing to do long term studies to evaluate the validity of predictions like these, but it has been done. The diet is not only effective in the long term, but I quote:



This study shows the beneficial effects of ketogenic diet following its long term administration in obese subjects with a high level of total cholesterol. Moreover, this study demonstrates that low carbohydrate diet is safe to use for a longer period of time in obese subjects with a high total cholesterol level and those with normocholesterolemia.




9. It gives you bad breath
When you're in ketosis, it's certainly detectable in your breath. What you're smelling is ketones, fruity-smelling molecules converted from fat for use as fuel by the cells. If you're the one in ketosis, it's actually quite satisfying to know that you're actually exhaling calories! And if you're the significant other, or potential date, it's not an unpleasant aroma - certainly nothing like halitosis.


10. I'll never be able to stick with it
There are some tricks to it, but if you do it right, it's easier than you think. If you eat a lot of fast food, you'll have a hard time. If you go out to eat a lot, there will be the temptation of convenience. The same is true if you keep a lot of starchy or sugary food around the house. But if you don't have or expose yourself to the wrong foods, you'll hardly notice you're even on a diet, because you're eating delicious food and your cravings will subside after the first week or two, if not sooner.