A “ketogenic” diet severely restricts carbohydrate intake to under 50 grams of net carbs per day (“net” carbs being only the carbs that actually are metabolized into blood sugar, as opposed to total carbohydrate intake which includes fiber).
In other words, Cheerios are off the table.
Related: Are Cheerios Chemically Castrating the American Public?
In so doing, in the absence of blood glucose, the body is forced to switch to an alternative energy source in the form of ketones converted from fatty acids in the liver — hence the term “ketogenic” diet.”
Ketosis through carb deprivation — in most cases a normal and, in fact, potentially therapeutic metabolic state, is not to be confused with diabetic ketoacidosis — which is potentially life-threatening. So if you have any form of metabolic dysfunction, it would be wise to consult with an endocrinologist before embarking on any new ketogenic adventure.
Via Stat Pearls (emphasis added):
Ketone bodies are prominent fuel sources for all evolutionary domains of life. The body can use ketones as a source of energy in the absence of a carbohydrate source. Ketones make up 5% to 20% of the human body's total energy expenditure. The liver converts fatty acids into ketone bodies that travel to other organs via blood. This process is especially important when an individual's blood glucose has decreased, and they must maintain an energy source for organs such as the brain. Ketone metabolism consists of the oxidation and utilization of ketone bodies by mitochondria, especially in organs with high energy demand. This process produces NADH and FADH2 for the electron transport chain and delivers acetyl CoA for gluconeogenesis. Prolonged fasting or vigorous exercise may lead to an excess of ketones and cause ketosis. One of the most feared complications in the setting of ketosis is in diabetic patients. When diabetic patients do not receive enough insulin physiologically or from supplementation, they will inappropriately enter ketosis, leading to diabetic ketoacidosis (DKA).
Maintaining a ketogenic diet is markedly more difficult than just a low-carb diet (commonly defined as under 150 grams of net carbs daily) because crossing the 20–50-gram net carb threshold is incredibly easy to do without extreme diligence. It’s also the case that excessive protein intake can raise blood sugar and kick the body out of ketosis, so macronutrient monitoring is a must.
That said, it may be worth doing.
The potential long-term negative effects of permanent ketosis, particularly on the hormones, haven’t been fully litigated yet, and it may turn out to be a net negative for some people, but the benefits of the ketogenic diet are increasingly borne out by research — including, potentially, preventing neurodegenerative decline.
Via Science Alert (emphasis added):
We know that a host of factors play into Alzheimer's risk, including the makeup of our gut bacteria. So, it makes sense that our diets might have some influence.
A new study found a chemical elevated by 'ketogenic' diets – which are low in carbs and higher in proteins and fats – can delay the early stages of Alzheimer's-related memory loss in mice. That memory loss is comparable to the mild cognitive impairment seen in people before Alzheimer's takes hold.
Key to the new discovery by a team led by the University of California, Davis (UCD), is the molecule beta-hydroxybutyrate (BHB), which the ketogenic diet increases levels of. Here, the researchers found BHB was particularly abundant in biological pathways associated with memory and brain plasticity.
(For what it’s worth, BHB can also be purchased as a supplement, although it’s unclear if it delivers the same potential benefits as the researchers found for endogenous BHB production facilitated by ketosis.)
Here is the link to the study that involved a 7-month observation of the effects of a keto vs. standard diet on neural plasticity and memory in mice.
