The Ketogenic Diet: A Guide for Beginners and Advanced Followers—Part 1

Dear BLOG readers, Dear PEAK customers,

I’m sure every one of you has heard or read this term before, but what exactly is “ketogenic”? “Something with few carbs”—that’s about the extent of most people’s knowledge in the sports community. Unfortunately, every year, many people with this limited understanding plunge into a drastic cutback on carbs, hoping that this alone will be enough to achieve their desired weight-loss goals. The result is often dismal diet failures, weight regain, and, consequently, negative reviews of a diet they never really took the time to understand.

My new two-part series puts an end to this by presenting the ketogenic diet in all its details—including its pros and cons—and equipping you with the necessary knowledge to decide for yourself whether this way of eating is right for you or not.

Enjoy!

What is the ketogenic diet?

The ketogenic diet is characterized by consuming only a very small amount of carbohydrates while eating larger amounts of fat. The goal of a ketogenic diet is to shift the body’s metabolism into a state of physiological ketosis, in which large amounts of fatty acids are converted in the liver into so-called ketones (ketone bodies). These serve as a kind of substitute energy source for carbohydrates (glucose) and are thus intended to meet the body’s glucose needs as much as possible without having to obtain it from daily nutrition. According to the theory, when substitute carbohydrates are produced from fatty acids, this results in the effective mobilization of fatty acids from fat stores and thus an equally effective reduction in body fat content.   

Over time, several variations of the ketogenic diet have emerged. The standard ketogenic diet consists of the following macronutrients (Freeman 2007):

• 75% fat
• 20% protein
• 5% carbohydrates

In the cyclical ketogenic diet, ketogenic days alternate with days of higher carbohydrate intake, whereas in the goal-oriented ketogenic diet, carbohydrates are always permitted in conjunction with physical activity. We are familiar with these forms of the ketogenic diet in connection with the so-called “anabolic diet,” about which I wrote a detailed review some time ago (please see “See Also” at the end of the text).

Ultimately, the high-protein ketogenic diet calls for a macronutrient ratio that is more protein-dominant.

• 60% fat
• 35% protein
• 5% fat

It’s important to note that studies almost exclusively use the guidelines from the standard ketogenic diet!

Conclusion

Ketogenic diets minimize carbohydrate intake with the goal of inducing ketosis in the body’s energy metabolism. Over time, several variations have emerged.

How the ketogenic diet works

The drastic reduction in carbohydrate intake leads to increased production of so-called ketones from fatty acids, primarily in the liver. These ketones serve as an energy source in place of carbohydrates, and the brain can also be partially fueled by ketones (LaManna 2009). The energy needs not met by ketones are met through a process known as gluconeogenesis. A nutritionally induced deficiency of carbohydrates and insulin triggers the release of a large amount of glucagon to stabilize blood sugar levels, which promotes gluconeogenesis. This process leads to an increased conversion of amino acids, in particular, into glucose. It is generally assumed that 1.6 g of amino acids are required to produce 1 g of glucose. If (as is often claimed) the essential daily carbohydrate requirement for humans were 100 to 120 g (or, according to McDonald, as much as 200 g for normal brain and muscle function), then 160 to 200 g (or even 320 g) of protein would have to be broken down to meet this need within the context of a ketogenic diet. Since skeletal muscle mass serves as the body’s largest amino acid store, this would correspond to enormous muscle loss—a finding not observed in studies, meaning there must be another factor at play. The answer is sometimes found in alternative energy substrates such as lactate or pyruvate, which, in addition to amino acids, can also be used to produce glucose—but there’s more to it than that….

How high is the actual need for carbohydrates?

Science has not yet provided a clear answer to the question of whether the human body truly requires the specified daily amounts of carbohydrates—and if not, how much it actually needs instead. What we do know is that, among all energy consumers, our brain accounts for 60 to 70% of the energy derived from normal glucose metabolism. In its article “How Much Glucose Does Your Brain Really Need?”, Marks Daily Apple cites the book *Endocrine* by Dr. Brandt. The book states that the brain’s glucose requirement is 120 grams per day. According to his analysis, the brain is capable of meeting up to 75% of this requirement through ketone bodies, which would ultimately mean an essential glucose requirement for the brain of 30 grams. “Up to” further implies that the actual requirement falls somewhere between 30 and 120 grams per day. A 2011 study also supports the possibility of meeting 70% of our brain’s glucose needs through ketone bodies. In contrast, a report by the U.S. Institute of Medicine states the following:

“The lower limit of dietary carbohydrates compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed.”

Conclusion

On the ketogenic diet, ketone bodies compensate for the daily requirement for carbohydrates. The scientific community has not yet reached a complete consensus on exactly how high this requirement actually is. What is certain, however, is that carbohydrates are NOT an essential macronutrient group and that we need far fewer of them than is often claimed.

Ketogenic Diets and Health

Numerous studies in the past have examined differences in the effectiveness of ketogenic diets versus low-fat diets with regard to key health markers. Ketogenic diets inevitably lead to a sharp reduction in blood sugar and insulin levels, accompanied by higher concentrations of glucagon and ketone bodies. These and other factors are now believed to account for various health benefits of a ketogenic diet, and indeed, many of these assumptions can be scientifically substantiated:

Weight Loss

Ketogenic diets are clearly the frontrunners when it comes to reducing body weight. With ketogenic diets, weight can be lost quickly (at first, it’s really just about the weight!), even though fewer calories are consumed on a low-fat diet. This can be explained by the flushing of excess water from the body. The drastic reduction in insulin levels causes the kidneys to excrete sodium and, along with it, increased amounts of fluid (Volek 2002, Tiwari 2007). Of course, water loss isn’t a great indicator of quality weight loss, but the scale will move very quickly once you start a ketogenic diet. Studies, such as those by Sondike, Volek, or Westmann, report double or even triple the weight loss on a ketogenic diet—and (to get this out of the way) all of this with significantly less hunger than was experienced on low-fat diets.

Despite all the praise, it must be noted that the benefits of a ketogenic diet often fizzle out in long-term studies (over 6 months) (Foster 2003), as weight gain resumes very quickly once the diet is discontinued and old eating patterns are resumed. What remains, then, is a permanent switch to the ketogenic diet—which, in practice, is easier said than done, given the undeniable lack of variety in food choices that this entails.

When theory meets practice, the ketogenic diet unfortunately loses its appeal very quickly. The reason is a drastic restriction in food choices that very few people are able—or willing—to accept on a long-term basis.

Hunger and Satiety

Binge eating, cravings, or straying from dietary guidelines have caused countless diets to fail. The lower the calorie intake and the lower the body fat percentage, the harder our body works against our goal of losing more weight—and the more obstacles it will throw in our path to tempt us into eating more again. You can find more on the topic of satiety here.

As mentioned earlier, ketogenic diets in particular seem to be excellent for appetite control (McClemon 2008). As a result, people on a low-carb diet instinctively consume fewer calories than those on a low-fat diet (Krebs 2010).

Studies show that people on ketogenic diets do not experience diet-breaking episodes and experience sustained satiety.

Visceral Belly Fat

Strictly speaking, whether body weight trends up or down (as described above) doesn’t really tell us much about what’s actually happening to body composition. That’s why findings such as those by Volek et al. from 2004 are particularly interesting. These findings suggest that ketogenic diets are especially effective at reducing visceral abdominal fat. For those unfamiliar with this term: it refers to fat located between the organs, which is considered to be particularly metabolically active and is therefore responsible for a large portion of the metabolic dysregulation mediated by fat cells (as well as for an increased incidence of inflammation) (Bergman 2012).

Ketogenic diets tackle the problem at its root by breaking down visceral fat deposits in particular.

Blood Lipids and Cholesterol

Ketogenic diets also have an excellent effect on cholesterol and triglyceride levels, which are associated with blood pressure, vascular health, and, further, cardiovascular risk (Patrick 2007). When it comes to triglycerides, in addition to low-fat diets (Parks, Ginsberg), simple sugars and fructose are considered particularly dangerous (Parks, Stanhope), whereas a well-managed low-carb diet can significantly improve HDL levels (Foster, Brinkworth) and, consequently, the triglyceride-to-HDL ratio (Da Luz, Shishebor, Urbina) can be positively influenced. Both markers can significantly alter the risk of cardiovascular disease (Toth, Gordon, Boden).

Of particular interest in this context is the effect of ketogenic diets on LDL cholesterol. In many cases, a reduction in LDL is beneficial, as high LDL levels are associated with a higher likelihood of heart attacks (Howard, Wilson). However, ketogenic diets offer even more benefits, as they also lead to an increase in the number of large LDL particles, which, according to recent studies, are significantly less harmful than small LDL particles (Wood, Campos, Lamarche, Packard).

While ketogenic diets may initially or temporarily lead to elevated triglyceride and cholesterol levels, this seems to resolve itself over time.

Diabetes

For all of the estimated 300 million people with type 2 diabetes worldwide, the ketogenic diet actually represents an excellent and logical alternative. Minimizing carbohydrate intake leads to lower long-term blood glucose and insulin levels (Yancy, Noakes) as well as improved insulin sensitivity (DeFronzo). In a study of people with diabetes (Westman 2008), 92.5% of the participants were able to reduce or even discontinue their medication within the first 6 months after switching to the ketogenic diet.

For people with type 2 diabetes, the ketogenic diet is an effective way to manage their diet.

Blood Pressure

High blood pressure, also known as hypertension, is considered life-threatening because it damages blood vessels; it is not without reason that it is regarded as a widespread disease. Studies such as those by Daly and Gardner clearly show that low-carb diets can lower elevated blood pressure levels.

If you have hypertension, take note—nutritional measures could successfully treat your condition.

Metabolic Syndrome

When obesity, high blood pressure, elevated fasting blood sugar, elevated triglyceride levels, and an unfavorable cholesterol ratio all occur together, this condition is referred to as metabolic syndrome—the “worst-case scenario” in terms of metabolic health. As we’ve already seen, ketogenic diets have a positive effect on many of the markers described. It’s therefore no surprise that studies such as those by Volek or Feinman describe the ketogenic diet as particularly valuable in the fight against metabolic syndrome.

If a dietary approach can improve individual symptoms, then it is also effective for the condition as a whole. For this reason, the ketogenic diet is successfully used to treat metabolic syndrome.

Brain

As previously discussed, a large portion of the brain’s glucose requirements can be met through ketone bodies and further through the body’s own gluconeogenesis. The extent to which this is also beneficial from a health perspective has been extensively and successfully investigated in recent years. Numerous studies see great potential in treating epilepsy with ketogenic diets, particularly with a modified version that provides 4–6% carbohydrates (10 g in the morning for children, 15 g in the morning for adults) without simultaneously restricting protein intake. A reduced frequency of epileptic seizures has also been observed with the use of MCTs (medium-chain triglycerides). Recent studies now also show positive results from the use of ketogenic diets in connection with Alzheimer’s and Parkinson’s disease, as well as with migraines.

Carbohydrate restriction does not cause lasting damage to our brain.

Other Diseases

Ketogenic diets are also used for other existing conditions, such as cancer. Ultimately, even acne has been successfully treated with a ketogenic diet thanks to reduced sugar intake and lower insulin levels (Paoli 2012).

Ketogenic Diet—These Risks Exist

In addition to the biggest problem—which makes the ketogenic diet interesting for many only in theory—namely the severe restriction in food choices and, in this context, a higher risk of various deficiency symptoms—studies have identified several other potential issues that should not go unmentioned here.

As already mentioned, ketogenic diets are associated, at least temporarily, with elevated cholesterol and triglyceride levels. The extent to which this also affects cardiovascular health has not yet been sufficiently studied. Studies such as that by Kapetanakis report that this effect becomes less pronounced within the first 24 months. In a 10-year comparison, Wibisono et al. found an increased risk of kidney stones with ketogenic diets, which should be addressed with potassium supplementation. Finally, constipation occurred very frequently (65% of cases), particularly in studies involving children. This is likely the result of a significantly reduced fiber intake. Here, too, appropriate supplementation is necessary to prevent negative side effects.

Conclusion

Where there is an imbalance, problems arise. This is also true of the ketogenic diet. Therefore, it is important to ensure a targeted balance.

Summary

Part 1 of my article introduced the concept of a ketogenic diet and defined the term. We now know what it is, what forms it takes, and what potential—but also what pitfalls—lie behind ketogenic diets in terms of health. Part 2 will first focus specifically on ketogenic diets in conjunction with exercise, before I share some practical tips on how to choose the right foods and supplements.

Until then, I send my best athletic regards 

Holger Gugg

www.body-coaches.de

Sources

Image source: akf/Fotolia.com

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What Does the Ketogenic Diet Do?

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