Part 2: Benefits and Side Effects of the Ketogenic Diet

In part one of this post, we looked at the basics of the ketogenic diet—a high fat, moderate protein, and low carb diet. We also looked at how it switches your body’s fuel source from glucose (from carbs) to fat. In this second part of the series, we’ll look at the benefits and side effects of the ketogenic diet.

Benefits of the Ketogenic Diet

The ketogenic diet is unique because its benefits go beyond weight loss. It’s been used to treat a range of health issues like neurological disorders and heart disease. Let’s take a look at some of the main benefits backed by research.

Weight Loss

The ketogenic diet forces your body to burn fat for energy in the absence of carbs. So, weight loss is an obvious benefit.

People will often lose weight quickly when they start the diet, but some of the initial weight loss will be water weight.

Hormonal changes are one of the main drivers of weight loss on a ketogenic diet. When we keep carbs low, we release less insulin. Insulin is a hormone that allows your body to use sugar from carbs for energy. It also stores the extra energy as fat for later use. When insulin is low, your body will tap into existing fat stores (like that beer gut) for energy.

Several studies have found the ketogenic diet to be more effective than a low-fat diet for weight loss. In addition, some people find they are fuller on the diet because of the high-fat intake and moderate protein.

Epilepsy and Other Neurological Disorders

As mentioned in part one, the original ketogenic diet has been used since the 1920s to treat drug-resistant epilepsy in children. It’s also been shown to reduce the symptoms of Alzheimer’s, Parkinson’s, sleep disorders, autism, and other neurological disorders.

When your body produces ketones, you provide your brain with a more efficient fuel source. Ketones act as antioxidants that prevent damage to brain cells. They can also decrease inflammation, support the survival of existing neurons, upregulate genes involved in energy metabolism, and improve brain function.

Reduced Risk of Diabetes

Carrying excess fat puts you in a higher risk category for diabetes and other metabolic disorders.

When we eat carbs, insulin is released as a reaction to elevated blood glucose. Insulin has a role in the development of diabetes and other health problems. The ketogenic diet reduces carbs stores to near empty. This prevents insulin from being released after you eat, and can help to normalise blood sugar levels.

Research has found that a ketogenic diet has benefits for improving blood pressure and reversing insulin resistance (the underlying problem contributing to diabetes). It can even help people stop or reduce their diabetes medication. 

Could Help Fight Cancer

This is an exciting new area of research. The ketogenic diet may be able to ‘starve’ cancer cells. How does this work?

We talked about how the body switches from burning sugar to fat on the ketogenic diet. Well, researchers believe that cancer cells can’t shift to use fat for energy instead of glucose. By restricting carbs the cancer cells are unable to grow. 

There are several studies and wellness experts that promote the ketogenic diet as an effective treatment for cancer. If I was ever diagnosed with cancer, it would be the first thing I’d do.

Reduced risk of Heart Disease

The ketogenic diet has been shown to reduce heart disease markers like body fat, HDL levels, blood pressure, and blood sugar.

As with many of the other benefits, the changes are a result of lower insulin levels and utilizing fat for energy instead of glucose.

Side Effects of the Ketogenic Diet

There are some major benefits to the ketogenic diet, but that doesn’t mean there’s no downside or that everyone should try it. Some people need more carbs in their diet, so struggle on a high-fat diet. What are some of the side effects you need to be aware of before trying the diet?

Transitioning to a High-Fat Diet

It can take days to weeks to transition to a high-fat diet. During this time, you’ll likely feel like crap. People report symptoms like low energy, mental fog, and headaches. This is known as ‘keto flu’. You’re not actually sick, but your body is adjusting to the diet.

When you eat a high-carb diet, your body has a lot of enzymes that break down and use the carbs as energy. It doesn’t have many dedicated to dealing with fat. When you switch to a high-fat diet your body has to build up a new supply of enzymes. This is one of the reasons why it takes time to transition into the ketogenic diet.

Sugar Cravings

One of the toughest parts of the ketogenic diet is being ultra-restrictive with carbs.

Our brains use more energy than any other organ. Your brain can use up to 20% of your total daily energy. That means that if you need 2,000 calories a day to maintain your weight, 400 of those calories are used just to power all those great ideas you have.

Because our brains prefer carbs, when blood sugar levels drop, we get intense cravings to consume quick energy. This will get better after you’ve transitioned into ketosis. That said, for people engaging in high-intensity exercise, carbs may be needed to support goals.

Drop in Strength and Physical Performance

Without carbs for energy, high-intensity exercise or weightlifting can be challenging. Some people report energy levels return when they’ve adapted to the diet. I personally felt weaker and had lower energy levels after a couple of months on a ketogenic diet.

If you’re trying to build muscle, you need carbs. Yes, there are some studies that show you can build muscle on a high-fat diet, but I don’t think it’s as effective.


Constipation can be caused by dehydration or a lack of fibre. Some people also find that they get constipated if they drop carbs too low, even when hydrated or taking in enough fibre.

The first thing to try is increasing your water intake. Also, make sure you’re getting enough salt or electrolytes in your diet.

Adding vegetables (non-starchy types) can also help. If that doesn’t do the trick, you may need to add in some carbs and modify the diet.


Many people report cramps on a ketogenic diet. They’re usually a sign of a lack of minerals. Try adding electrolytes or a magnesium supplement to your diet.

Don’t be afraid of salt—it’s essential for good health. When you’re on a ketogenic diet, you need more salt to counter the diuretic effects. Use a good quality rock salt and use your taste buds as a guide to how much you need. 

The Ketogenic Diet Isn’t for Everyone

Now that we’ve covered the pros and cons of the diet, I’d like to leave you with this: there is no one perfect diet. What works for your friends or family won’t necessarily work for you. Some people do really well on a high-fat diet while others find it hell. You need to test out different approaches and see what works best for you.

Do Your Research

If you are considering trying the ketogenic diet, I suggest speaking to a nutritionist, naturopath, personal trainer with nutritional training, or another professional who can help guide you through the diet. If you don’t want to go that route, do your homework and make sure you are aware of the side effects.

Part 3 - How to Put Your Body Into Ketosis

Tune in next week and I’ll tell you how to put your body into ketosis. I’ll also give you some ideas of foods to eat and avoid.

Do Something—Anything!

Don’t just consume information. If you’ve read this far, I’m assuming you find this post useful. You’ve now got two choices: 1) close the screen and think ‘that’s nice’ and move on with your day. Or 2) if you’re considering the ketogenic diet, commit to reading the next week’s post to learn the basics. It’ll give you the information you need to take action. Remember: decision creates action. Action creates results.

I Need Your Help

I’ve also got a huge favour to ask of you. No, I don’t want your money. But will happily accept it! I’m trying to get this blog off the ground and I can’t do it without your help. Simply sharing this post on social media (you’re so close to the share buttons—look down below) or emailing it to a friend makes a HUGE difference in my life. In return, I promise we can be best mates and you can reach out anytime. Seriously. If you need help with any health, fitness, or Jedi Knight goals you can contact me here.

You can also share some love by adding a comment below. Let me know if you’ve tried the ketogenic diet or a high-fat diet. Did you love it? Hate it?

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