3. Ketogenic Eating May Have Negative Consequences.
There are a lot of little side effects considered to be “negative” on ketogenic diets. There are some small positives as well (such as increased mental clarity). I’m not going to hash out all the little things here. I want to hit on two of the top negative consequences.
Ketosis requires very low carbohydrate consumption. In my article, The Practical Truth About Carbohydrates, I noted that one of the potential downsides of this is a reduction in your metabolic rate.
The mechanism for this is chronic calorie restriction, which can easily happen on ketogenic protocols due to the satiating nature of fat and protein. In other words, it’s common for people on ketogenic diets to accidentally under-eat because ketosis does such a great job of turning off hunger.
This paradigm is especially destructive when sleep, stress, nutrient density, and inflammatory exercise are not considered. Doing ketosis properly requires having ALL of your ducks in a row.
Another consequence of ketosis is a potentially negative change in gut flora. The mechanism for this is a lack of fermentable substrate—the stuff your gut bugs feed on—as well as a change in the pH of the gut. You can read more about this, if you’re interested, at The Human Food Project.
The study of the gut biome is a relatively new science and is highly complicated. I’m not taking any hard-line stances on this right now, but you should note that if the science continues to trend in the direction it’s moving, it spells potential disaster for long-term, very low carbohydrate or ketogenic protocols (and those following ketogenic diets for medical reasons will need to look at strategic supplementation of fermentable fibers).