How to Use the Ketogenic Diet to Improve Body Composition

October 20, 2016

Imagine eating thick slabs of bacon with a three-egg omelette (with yolks!) for breakfast almost every day while looking and feeling good at the same time.

But wait, aren’t bacon and egg yolks synonymous with every disease out there that’s associated with high cholesterol levels?

Well, it turns out that dietary fat is not what we thought it was supposed to be. Cardiologists are even starting to question the conventional wisdom of fat being like a big bad wolf that’s out to get you by making you fat and wrecking your health.

This is even starting to show up in pop culture. For example, in an episode of Vice’s Munchies, elite runner Timothy Olson talks about how he conquers 100-mile mountain running competitions by teaching his body to become “fat-adapted”, popularly known as “going keto”, shorthand for following a ketogenic diet.

But you’re not an elite runner nor a bodybuilder.

You just want to get rid of your beer belly, look good next summer, and keep your energy levels high throughout the day (minus countless cups of coffee or bottles of energy drinks). Living stronger as you age is an added bonus!

So is going keto for you?

In this blog post, we’ll take a look at keto — what happens to your body when you go on a high-fat diet, its benefits, and possible drawbacks.

You’ll also learn how eating more fat can potentially help you reach your body composition goals - rather than work against them -  by helping you drop your body fat percentage, without losing Lean Body Mass.

Ketogenic Diet: What is It?

For anyone who is keen about going keto, the general idea is to kick carbs to the curb. It’s a high fat, moderate protein, and very low carb diet.

Since the resurgence of the ketogenic diet’s popularity in the 1990s, diets patterned after its main premise of eating more healthy fats and limiting carbs have emerged. These diets include the South Beach Diet, Atkins Diet (its induction phase in particular), modified Paleo, and other low-carb diets.

The good thing about adopting a ketogenic diet is you can be vegan, vegetarian, hardcore Paleo, or an Atkins fan and still achieve ketogenesis. Focusing on your fat, protein, and carb ratio as well as where those nutrients come from is also important.

As a rule of thumb, focus on foods that are naturally high in fat and avoid highly processed foods that are labeled with trans-fats as much as possible. In addition, eat your greens, yellows, and reds from vegetables. Pay more attention to fruits that are low on the glycemic index but are still rich in fiber and other foods like avocados (also for the fat!) and berries.

A Typical Keto Diet

A typical keto diet can include the following:

  • Meat (grass-fed and free-range is better) - pork, chicken, beef, eggs. Vegans will need vegetable protein sources
  • Nuts and seeds
  • High-fat dairy such as cream, whole butter, and hard cheeses
  • Leafy greens
  • Fish and seafood
  • Olive oil, coconut oil, pure butter, vegetable oils rich in omega 3

What to avoid:

  • Any food that’s made of starch (even whole grain, organic bread)
  • Most fruits (since they are extremely high in sugar)
  • Any food that’s labeled with low-fat
  • Vegetable oils rich in omega-6 and low in omega-3

To learn more about what kind of fat is right for you, this guide is a good start.

Some keto dieters add alcohol and coffee ( minus the cream, milk or sugar) in moderation to their diet. Others, however, stay away from it. Experiment with these beverages and figure out what works for you.

A Sample Keto Dinner

To help you get started, here’s what a sample keto dinner would look like:

Bye Bye Carbs - Bring on the Bacon

For pretty much all of human history, in virtually every corner of the world, people have been relying on foods rich in carbs as the foundation of their diet.

Think wheat and barley in Eurasia, rice and millet in the Far East, corn and beans in the Americas, and yams and taro in the Pacific. That’s because carbs are an excellent source of calories and your body’s preferred energy source.

However, in today’s fairytale world of industrial agriculture, caloric abundance, and sedentary lifestyles, we tend to rely on carbs too much, and we overdo it. The glucose from excess carbs is quickly metabolized by the body, but gets stored as fat when unused. The result: a staggering increase in obesity.

Going on a ketogenic diet, on the other hand, trains your body to rely on dietary fat for energy by converting fat to ketones and free fatty acids (FFAs). This natural metabolic state is often referred to as ketosis.

Reaching ketosis means you have to limit your carb intake to encourage your body to produce ketones for energy.

In a nutshell,  you reduce your carb intake to around 30 to 50 grams of net carbs, leaving your body with no choice but to rely on dietary fat as an energy source.

30-50 grams of carbs is not a lot. For reference, a piece of white bread has about 15 grams of carbohydrates in it. If you were to eat a sandwich and use two pieces of bread, that’s it, you’re done for the day with carbs.

Net carb is the total amount of carbs you consume minus its fiber content. To calculate net carb content, you simply deduct grams of dietary fiber from grams of total carbs per serving.  Food labels usually have this information.

Your Body on Keto

In a standard diet, carbs are broken down into glucose as your primary energy source. The remaining glucose that isn’t utilized is converted into glycogen and stored in the muscles and liver for later use.

Meanwhile, a ketogenic diet aims to change this. If you go keto, your body goes into a glycogen-deprived state because of the low carb intake. Instead, fat is oxidized to produce energy, resulting in ketones.

In contrast to glucose, which tends to provide quick bursts of energy (sometimes leading to a dreaded sugar “crash”), the energy you gain from fat burns slower. As a result, you may avoid those sugar crashes right after a high-carb meal by going keto.

Sure, some organs in the body require a certain amount of glucose to keep functioning (the brain is a good example). Yet, your body is a wonderfully capable machine that can meet its minimal glucose requirements even in periods of famine or deliberate fasting.

In fact, it has been shown that ketones have neuroprotective benefits. This means your brain won’t rebel if you decide to opt for ketones as your main energy source.

Since unsaturated fat has been shown to be more satiating, a ketogenic diet helps curb overeating and has become an attractive alternative for folks who want to lose weight and improve body composition.

Besides the high levels of satiety resulting from fat, individuals on a high-fat diet often report that they are less hungry. Often, this is because their blood sugar levels are more consistent.

Adapting to Keto: The Adjustment Phase

Like many other good things, your body tends to resist change, and flu-like symptoms may develop around the first few weeks of going keto. Think of it as your body’s way of expressing its reluctance to stop relying on carbs too much and learning how to count on fat for fuel.

When you’re on a ketogenic diet, fatty acids are released from your body fat while your insulin levels become reduced. When your insulin levels reach extremely low levels, your kidneys will start to excrete lots of water (you’ll notice an increase in the frequency of trips to the bathroom), sodium, and potassium. As a result, your blood pressure level can plummet. Dizziness, fatigue, and sudden weakness are symptoms of low blood pressure. Leg cramps may also occur as your body runs out of fluid and electrolytes.

To combat keto-flu and leg cramps , increasing your electrolyte and fluid intake is recommended, particularly during the first few weeks. Bone or vegetable broth consumption is also helpful.

In addition to keto-flu and leg cramps during the first few days of going keto, reduced physical performance has been observed during periods of keto adaptation.

A review of studies on ketogenic diets and physical performance concluded the following:

...anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics.

So, the bad news is that if you’re an athlete and you depend on performing at 100% to maintain your position (or your job, if you’re a professional), going keto in-season is likely not the best option for you.

The good news is as your body adapts to using fat as fuel, you are most likely going to enjoy the steady, slow-burning kind of energy that results.

Going Keto: What’s In It For You

First time keto-dieters want to lose weight.  And it looks like these folks are going in the right direction because as we’ll see, ketogenic diets can be very useful for reducing body fat.

But before getting into that, a word of caution. Like all types of weight loss regimens that dramatically reduce carb intake, it’s normal to lose weight quickly during the first two or more weeks, and then see it slow. Because glycogen bonds to water, if you have less glycogen in your body because you’re consuming less carbs, a lot of the initial weight loss is water weight - not body fat.

A 2013 study comparing the ketogenic diet to a low-fat diet revealed that the former is effective for weight loss. The researchers concluded that very-low-carbohydrate ketogenic diets (VLCKD) may be studied further to help curb the obesity epidemic.

Another study compared the effectiveness of a low-carb keto diet (less than 10% calories from carbs) to a low-fat diet amongst obese men and women. The researchers concluded that the low-carb keto diet was effective in short-term body weight and fat loss (particularly in men) even when the caloric deficit (-500 calories) was the same for both diets.

Besides fat loss, other health benefits of a ketogenic diet are discussed in detail in this review of the scientific literature. According to the researchers, several studies have shown that VLCKD has been shown to reduce risk of the following:

  • Cardiovascular disease
  • Type 2 diabetes
  • Epilepsy
  • Cancer and tumor progression
  • Polycystic ovary syndrome
  • Neurological diseases such as Parkinson’s and Alzheimer’s
  • Amyotrophic lateral sclerosis
  • Acne

Additionally, a ketogenic diet has potential useful effects in patients with increased carbon dioxide levels as a consequence of respiratory failure.

Keto and Body Composition

Unlike the catabolic (muscle loss) effects of calorie-restriction diets due to protein breakdown from a lack of carbs or fat, going keto is different.

By and large, your body is not forced to break down its protein reserves. Instead, because you're already consuming a high-fat diet, it will turn its attention to breaking down fat.

In an 11-week study of of men who performed resistance training three times a week, the researchers found that lean body mass increased significantly in subjects who consumed a very low carb, ketogenic diet (VLCKD) compared to those  who stuck to a  traditional heavy-carb Western diet. Significant fat mass loss was also observed amongst the VLKCD group.

Furthermore, a study on patients who underwent radiotherapy for cancer treatment revealed that a  self-administered ketogenic diet helped these patients preserve muscle mass while losing weight.

Keto, however, may not work for someone who’s looking to gain body weight by increasing their Lean Body Mass or for competitive athletes. To develop LBM, your body needs large glycogen stores to power your muscles, and often requires that you be in a caloric surplus - not maintaining or reducing them. In this case, a whole different approach to nutrition is required.

Is Keto For Everyone?

Despite its multiple benefits, the high-fat and low-carb nature of the ketogenic diet may not be recommended for:

  • Type 1 diabetics, who may experience diabetic ketoacidosis (not to be confused with ketosis) due to increased levels of ketones in the body
  • Individuals having issues with  metabolizing fat and similar metabolic disorders
  • Women who are thinking about getting pregnant
  • Children because they still need carbs for growth and development
  • Although it has been shown that ketogenic diets may reduce cardiovascular disease risk,  individuals with blood lipid profile issues may need to check with their doctors first and/or closely monitor their lipid profile levels while on the diet

You should, of course, consult a health professional before making such a major change in diet if you have any concerns about how it may affect you and your lifestyle.

Should I Be in Keto Forever?

Say you’ve accomplished your body composition goal. Should you go back to your usual diet and stop going keto?

It’s up to you. Everyone’s goals and lifestyles are different. There’s nothing that says that you can’t stay on a ketogenic diet if you like it; for some people, this is the only diet that promotes good health.

What’s important is that you continue to be mindful of what you eat -how much and where it’s from - in order to achieve your health goals.

Like everything else in nutrition and fitness, it pays to be skeptical and to always start with a learning mindset. Admittedly, that's pretty frustrating for people who are serious about their health and fitness.

That's why it also pays to keep up with new studies that are reported on in the media. Scientists and researchers are always challenging what they know, and it may be that what we believe to be true today could be refuted next year or the year after.

The best you can do is try things out, track your progress, discard whatever isn’t working, and keep learning. Think of a keto diet as one strategy in your arsenal to achieve your body composition goal, whatever that goal may be.


Kyjean Tomboc is a nurse turned freelance healthcare copywriter and UX researcher.  After experimenting with going paleo and vegetarian, she realized that it all boils down to eating real food.