What Is the Keto Diet?Posted: August 6, 2019 in Healthy Eating by Craig Primack MD FACP
Advocates of the keto diet claim that it offers a variety of health benefits, including improved metabolism, more energy, rapid weight loss, superior concentration, better bone density, anti-inflammatory properties, lower stress levels, and even an improved ability to build lean muscle mass. Others are skeptical of anything that makes so many claims. Perhaps unsurprisingly, the truth lies in between these two extremes.
At its core, the keto diet is the consumption of a lot of fats (at least 70 percent of total caloric intake), while minimizing carbohydrates (less than five percent of caloric intake). Protein makes up the rest of the diet (roughly 25 percent of caloric intake). If you stick to a keto diet for an extended period of time, you will probably lose weight by altering your body’s biology.
The Science of Keto
Generally speaking, the human body derives energy from a process called glycolysis that burns glucose (a simple carbohydrate). Fats are stored for later, emergency use: an evolutionary survival mechanism that dates back to before food was as plentiful as it is now. This is the body’s preferred method of creating energy, but there are other options if glucose is not available in sufficient quantities.
The alternative most relevant to the keto diet is called ketosis. Under a state of ketosis, the body directly burns fat to produce energy, with no glucose involved. If your goal is to get rid of fat, forcing your body to burn it instead of glucose is a scientifically sound way to go about it.
The Problem with Keto
Unfortunately, it isn’t as easy as switching to a high-fat diet and losing weight. The human body does not give up glycolysis until it absolutely has to, which generally requires following a strict keto diet for three entire months before ketosis kicks in and you start seeing results. Worse, many people experience adverse side effects, such as headaches and lethargy, while waiting for ketosis to kick in.
There are numerous dietary supplements that claim to be able to speed up this process, most of which have a formula including beta-hydroxybutyrate (BHB). BHB acts as a substrate that perks up the enzymes responsible for converting fat into energy. However, the research is currently lacking as to whether such supplements are safe for prolonged use or effective for weight loss.
Once you achieve ketosis, you’re still not out of woods. The body still has an evolutionary preference for glycolysis, meaning that one carb-heavy meal can switch you back to glycolysis and force you to “earn” ketosis all over again. Most diets have some sort of leeway, allowing you to make up for excess calories by exercising more or eating fewer calories for a couple of days. Keto does not offer this flexibility, making it a very rigid dietary regimen that most people find hard to stick with.
While keto has the potential to help you lose weight, it can be tough to stick with long enough to see the results you are looking for. If you want to try it anyway, it is always best to consult with a medical professional before beginning any diet program.