Everything you need to know about keto – what it is, how it works, if it’s safe, why there’s even a diet that specifically excludes pasta, potatoes, bread, rice, and all other carbohydrates – is right here.

First, let’s acknowledge and appreciate that there’s not one single “diet” or style of eating that’s better than another.

Each body is different with its own unique, individual needs and caloric requirements – the specific number of calories you need per day for your organs and body to function properly is called your Basal Metabolic Rate (BMR). When daily movement and physical activity are factored in, those caloric needs increase to yield a new number of calories; Total Daily Energy Expenditure (TDEE). To maintain your current weight, you’d need to consistently consume your TDEE worth of calories, above your TDEE to gain weight, and below your TDEE (but above your BMR) to lose weight.

With that said, what is keto?

Keto is a diet or method of eating that’s very low in carbohydrates (CHO for short), high in fat, and moderate in protein.

A typical keto diet ranges from 20-40 grams of carbohydrates per day, max. For context, the Dietary References Intake (DRI, a set of reference values used to plan and assess nutrient intakes of healthy individuals) for carbohydrates is 130g per day for men and women. That number, 130g of CHO, is based on the average minimum amount of glucose, or carbohydrates, the brain uses each day. Essentially, it’d take 3-6 days on the average keto diet to equate to 1 day of the recommended DRI carb intake. The National Academy of Sciences developed the Acceptable Macronutrient Distribution Range (AMDR) which recommends that carbohydrates make up 45-65% of a person’s total daily calories. The percentages are derived from scientific evidence indicating that range best prevents essential nutrient deficiencies and decreases the risk of chronic diseases. Based on the standard 2,000 calories per day, that amounts to 225-325g of CHO per day.

Carbs are clearly crucial. Once consumed, most carbohydrates are broken down into glucose (AKA blood sugar) to be used as energy for cells, tissues, and organs. Among their many functions, they’re a quality source of fiber, fuel for most physical activities, and red blood cells as well as some nerve cells in the brain and eyes are entirely dependent on glucose, thus requiring a constant source of CHO (that the body will break down to glucose). So why do the carb ranges in the keto diet fall so far below these reputable, empirical evidence-based recommendations?

What’s a ~keto~?

Keto refers to ketosis, ketones, and ketogenic.

Ketosis is a metabolic state. To burn and utilize fat efficiently, your body needs CHO (in the form of glucose). When CHO aren’t readily available – as they aren’t in the keto diet – the liver cannot break down fat completely, so it produces ketone bodies, or ketones as a result. Ketone bodies are metabolic by-products (think leftovers) of excess fatty acid metabolism. Ketones can serve as an energy source in most cells (but not all, remember how some cells solely depend on glucose) and are critical during periods of fasting and starvation.

Normally produced in small amounts within the body, ketone levels increase in certain situations: fasting, the presence of diabetes, chronic alcoholism, and low-carb, high-fat diets. Too many ketone bodies can lead to ketoacidosis though, which occurs when the body cannot properly regulate ketone production or ketones are being produced quicker than the body can use them and it creates a buildup of ketones in bodily fluids and tissues. In most cases, the accumulation of ketones results in dehydration and significant decreases in the pH of the blood (making the blood increasingly acidic), but in extreme cases of ketoacidosis, coma or death may occur. An absolute minimum of 50-100g of carbohydrates per day is recommended and required to prevent this risk.

Why is the low-carb + high-fat combo so popular?

Because it always has been. Low-carb diets morph and transform to fit social norms and over time, are reborn again under different aliases. Look at the Atkins Diet.

Objectively speaking, when CHO intake is too low to maintain blood sugar levels and support the central nervous system (CNS, brain and spinal cord) due to insufficient amounts consumed, gluconeogenesis occurs. Gluconeogenesis is a fancy term for when the body forms new glucose from proteins and fats (instead of carbohydrates, because remember that your body breaks carbs down into glucose). Hence, the high fat component of a keto diet – minimal carbs spark gluconeogenesis where glucose can be formed from the high amounts of fat, which is thought to compensate for the lack of carbs that would otherwise be providing the much needed glucose.

What does the body use first to form new glucose, protein or fat? The body will first draw protein from bodily tissues to form new glucose; 1 gram of protein results in 0.56 grams of glucose. Then the body will to fats for glucose. When fats are digested, they break down to fatty acids and glycerol and it’s glycerol that can be converted to glucose via gluconeogenesis in the liver; 1 gram of glycerol produces 1 gram of glucose. 

Compared to protein, fat yields a greater amount of glucose – it’s an even 1:1 ratio, which is why keto diets are so high in fat.

The basic rationale behind the ketogenic diet is that due to the extremely low CHO content, one’s body will then resort to utilizing consumed fat and both body fat for energy. A way of eating that targets and burns body fat? That sounds like a dream come true, right? Perhaps…

Exercising on a keto diet

At rest and during low intensity exercise (think yoga, walking, and other activities that aren’t particularly strenuous), fats are the main source of energy. As the intensity increases from low to moderate and then high, as does the body’s dependence on carbohydrates for energy. The gradual transition from fats to CHO as the energy source is called the crossover concept; this occurs at about 65-85% of a person’s working capacity. Above that is when CHO are the primary source of energy fueling the activity.

Adopting a keto diet could actually do more harm than good if you work out regularly, especially if you do so with the intention of developing muscle. When gluconeogenesis happens and the protein stores in your bodily tissues start to be tapped into for energy, that protein is coming from your muscles – the same muscles you’ve worked so hard for in the gym. So basically, you’ll exercise only for the muscles built to be wasted and burnt due to unsupportive eating habits, which is entirely counterproductive if you ask me.

As mentioned, the need for carbohydrates (to be used as energy) parallels the increase in exercise intensity. CHO are a more readily available source of energy than fats; in fact, they’re an immediate source. How? Because fats are stored in remote sites of the body in subcutaneous fat (under the skin, what you can physically see and touch) and visceral fat (protective, essential fat around the organs), while carbs are stored in muscle cells. If fats are to be used for energy, they’ll need to travel through the bloodstream to the muscles whereas carbs are already in the muscles just waiting to be utilized.

Aside from immediate energy, CHO can be used as an energy source for short periods of intense exercise without needing oxygen – or anaerobic exercise that’s less than 2 minutes. When CHO are metabolized by the body, they require less oxygen yet produce more ATP (energy) than fat. Per unit of oxygen consumed, CHO produces 2.7 ATP while fat produces 2.3 ATP.

Studies show enhanced activity within the sympathetic nervous system only 3 days after reduced carbohydrate intake (think keto or other low-carb diets). An enhanced sympathetic nervous system can lead to anxiety, fatigue, irritability, nervousness, poor recovery, decreased quality of sleep, and more.

Contrarily, routine exercise increases the muscle’s ability to store and use CHO for energy; AKA when you exercise regularly, your body processes carbohydrates more efficiently! Consuming carbs after exercising can help restore blood glucose levels, replenish muscle and liver glycogen stores, and prevent Delayed Onset Muscular Soreness (DOMS, the soreness you may feel the days after working out).

So if you typically partake in moderate to high intensity workouts, keto might not be the best choice for you. While ketones have the ability to be used by muscles, they do not appear to significantly contribute to energy production during exercise. If you don’t work out consistently or your workouts are low-impact or of a lighter intensity, then a short-term keto diet administered and monitored by a professional (!!!) MAY be suitable for you. And at the {assured} risk of sounding redundant, I really want to reiterate and emphasize this: short-term, monitored by a professional, may be appropriate for you depending on the situation.

Does keto work?

Under specific conditions and for some individuals, keto can be beneficial if used for short periods of time, no longer than 2 weeks. For instance, low calorie, low-carb diets can be helpful regarding adjustment and regulation of blood sugar levels and rapid weight loss for those who are diabetic or obese.

Numerous studies have compared a keto diet to a balanced diet (that falls within the AMDR ranges of protein, carbohydrates, and fat). Initially, those committed to a keto diet lost more weight. But for the overall duration of the diet, there were no significant differences in weight loss between a keto and balanced diet. So the individuals following a balanced diet that placed them in a caloric deficit lost the SAME amount of weight as those on a keto diet – which is more drastic, unreasonable, and much harder to realistically adhere to in the long-run.

Extreme fad diets and low-carb tactics may be enticing, but there’s a laundry list of less than desirable effects that accompany them: lack of energy, weakness, headaches, nausea, gastrointestinal distress, decreases in blood volume, heart muscle tissue, and HDL (“good” cholesterol), inflammation of the intestines and pancreas, increased stress and strain on adrenal glands, micronutrient deficiencies, brittle hair and fingernails, and more. All of these negative impacts are exacerbated if adhered to for prolonged periods of time.

When adopted over the long term, high-fat regimens aren’t much better: high blood pressure, heart attack, atherosclerosis (build-up of plaque in the arterial walls), coronary heart disease, and obesity to name a few of the serious medical conditions that high-fat diets heighten the risk of.

Bear in mind that keto endorses low-carb AND high-fat. The National Academy of Sciences indicated the combination of very low-carb and very high-fat diets may be a predisposition to coronary heart disease, which is the #1 cause of death in industrialized countries.

Not only is a balance of carbohydrates, protein, and fat equally as effective as keto for weight loss, but its better in terms of overall health, wellness, and quality of life both now and down the road.

When it all comes down to it

We NEED carbs. It’s indisputable. Human bodies physiologically need them. If carbohydrates weren’t necessary, they wouldn’t be one of the three macronutrients (along with protein and fat). And the mental and emotional value of carbohydrate-filled foods such as cookies, fruit, pizza, and pasta goes without saying.

While there are some noted advantages to keto, it’s largely dependent on the duration, person, and their health history. When someone sees results from implementing a keto diet, I personally believe it’s because of one or both of the following reasons: one, the carbohydrates removed were mostly processed, simple carb sources with added sugars, artificial ingredients, and less nutrients than complex carb sources and two (and most importantly), in previous efforts to lose weight, they weren’t eating in a caloric deficit but now are since cutting out carbs, a substantial supply of calories. Both reasons aren’t directly related to the keto diet in that going keto is the secret, magical answer to weight loss. Results from keto are often indirect; keto promises stark transformations when in reality, it’s just another (unnecessarily strict) set of guidelines to change a person’s eating habits to eat in a caloric deficit, which is the one tried and true way to lose weight and sustain that weight loss.

Apart from allergies and sensitivities, depriving yourself of a certain food or food group isn’t physically, mentally, or emotionally healthy. It’s not noble or a haughty display of self-control like society esteems it to be. It’s human nature to want something all the more the moment you cut it out cold turkey. Restrictive eating habits are the polar opposite of a balanced, positive relationship with food. I encourage you to take these crash diets with a grain of salt. And instead, educate yourself on basic nutritional needs or choose a certified nutrition professional who can show you what your body needs and ensure you’re eating the correct amounts in a manner that’s practical and enjoyable for you. Equipped with knowledge, you can truly lead a healthier, happier life and use your discernment for the next trendy diet that’ll inevitably pop up and become mainstream.