Keto was the most-Googled diet of 2018. But what is it?
The aim of a ketogenic diet is to limit carb intake to under ~50 grams a days. For reference, a low carb diet suggests 50-150g per day. When carb intake goes lower than 50g, most people start producing high levels of “ketone bodies” – breakdown products of fat, and are used to fuel cells that normally depend on glucose.
While it sounds good, keto’s impact on health isn’t so simple.
Your brain and nervous system usually run on glucose. Fueling it mostly with ketones may provide benefit, but may also be harmful. The main condition this has been studied for is epilepsy, but more research on other conditions is underway. Keto’s impact beyond that is more complicated. While claiming to aid weight loss better than any other diet, the evidence is mixed but tends to show fairly similar results.
It’s trendy, but is it really good for you?
There are a few reasons why keto might not be totally safe:
First, high levels of ketones can be dangerous as they can lead to ketoacidosis (dangerously high ketone levels typically caused by diabetes). However, it doesn’t seem to occur without an uncontrolled medical condition.
Second is going too long without getting “enough” carbohydrates. This is generally safe, as you can make all you need to survive by a process called gluconeogenesis. Having said that, there isn’t any trial evidence though on what the long term effects (e.g. 5-10 or more years) of carbohydrate deprivation are, and whether ketogenic diets have any negative impact on unstudied health conditions, certain genotypes, etc.
Finally, there are claims of harm from diets high in animal products, which most keto diets are. This claim is nearly impossible to evaluate given the huge number of studies involved with varying conclusions. What we know is that evidence is mixed, and slightly differs depending on the animal product in question.
To put it bluntly, keto diets can have benefits, but also may be detrimental to different people. It is not a diet that we recommend everyone adapts, more so, we actually recommend a more sustainable approach for the long term. Carbs are not your enemy, thus should not be eliminated aggressively.