The breakdown of fatty acids under ketosis produces acetone, acetoacetate, and beta-hydroxybutyrate molecules, also known as ketones — which serve as an alternative fuel source for the body under the scarcity of glycogen induced by the ketogenic diet.
People experiment with all sorts of crazy diets, but the ketogenic diet might have the most evidence supporting (and criticizing) its claims next to the Mediterranean diet. Staving off carbs while keeping your body fueled with fats has attracted widespread attention for being a great way to lose weight — but not everyone is about the high-fat, low-carb train.
As one of the most popular diets in the United States, the keto diet promises a number of health benefits besides rapid weight loss, including:
This “shock to the system” may help shed the pounds, but several experts have called it no more than a “fad diet,” with some evidence even suggesting that the keto diet may increase the risk of heart disease and stroke.
The hidden meaning: A “diet” requires a very personalized approach that considers your preferences as well as biological requirements. Above all, it requires knowledge about the benefits and potential downfalls — something we don’t really consider beyond buying a new phone.
Your body primarily burns carbs for energy, falling onto fats when the starches are just not enough. Take away the carbohydrates, and two metabolic processes — gluconeogenesis and ketogenesis — come into play.
Ketogenesis is what drives fat loss during the keto diet. Falling glucose levels cause the body to break down fats for energy — producing ketone bodies that become our primary source of energy. This state is called “nutritional ketosis,” or simply ketosis.
Initially used to treat epilepsy in children, the ketogenic diet required 90 percent of the calories to come from fat, with 4 grams of fat for every 1 gram of protein and carb.
The standard keto diet model is more flexible, allowing nearly 70 percent of calories to come from fat, 20 percent from protein, and restricting carb intake to less than 10 percent.
Unlike the popular belief that a diet isn’t for fast weight loss, most keto diet proponents claim exactly that. The “speed keto” diet even combines intermittent fasting and keto to achieve greater benefits, even if it comes with more of a learning curve.
Even if not the easiest to stick to in the long term, studies show that a ketogenic diet can result in significant weight loss.
Experts recommend “keto cycling” as a more sustainable approach — especially since sticking to the ketogenic diet long term can cause a rebound.
Studies have found that the five main components of metabolic syndrome — obesity, high fasting blood sugar, high triglycerides (TGs), low HDL (good) cholesterol, and hypertension — are all improved when carbs are restricted.
Initially established as an option for treating drug-resistant epilepsy, evidence now suggests the keto diet to be beneficial for treating diabetes, respiratory illnesses, skin conditions like acne, and even has a “profound effect on brain function.”
A study published in 2022 even found that the ketogenic diet increased skeletal muscle mitochondrial mass as well as muscle strength and endurance in older mice — and even increased their longevity by 13.6 percent.
We’re sugar-driven machines, and as such, starving yourself of your primary fuel may not be the right thing for most people — at least not in the long term.
Is it safe: According to the U.S. News & World Report, the ketogenic diet is one of the worst overall diets in 2023.
While multiple studies have shown the ketogenic diet’s beneficial short-term effects (up to 2 years), its long-term health implications have not been well established. Critics say that the keto diet only works short-term, and might even lead to some eating disorders.
It is currently recommended for the ketogenic diet to be followed for a minimum of 2 to 3 weeks, up to a maximum of 12 months.
The takeaway: Keto doesn’t work for anyone, but the most benefits from the diet are achieved in a 6 to 12 months period, particularly the weight loss. For certain chronic conditions, however, it might be a lifelong approach.
The majority of your daily calories should come from high-fat foods, such as eggs, fatty fish, meat, nuts, and avocados.
Getting used to a new way of eating requires taste, which means that clearing away all forms of grease from your plate might not be the right choice.
Butter, ghee, olive oil, and full-fat dairy are great ways to add taste to your diet while keeping the carbohydrate levels low while adding some extra fat to the diet.
Keto flu is a common side effect experienced by someone trying out the keto diet for the first time. It typically occurs as your body struggles to shift its energy source, or due to a loss of electrolytes — caused by the diuretic effect of the keto diet.
Symptoms of the keto flu include:
It typically goes away within a few days. During this period, you may also experience reduced strength and endurance as your body adapts to keto.
Other common side effects of the keto diet include:
What you can do: Increasing your water intake and supplementing with electrolytes can help alleviate the initial symptoms. In case you experience these side effects for longer than a week, you should talk to a nutritionist or switch to a regular diet.
Some people may experience more serious side effects from the ketogenic diet, especially in the long term, including:
The lack of research on the long-term effects of the keto diet makes most experts reluctant in recommended the diet for extended periods. Keeping your doctor informed and even frequent bloodwork help keep an eye on your health during the diet.