Beginners Guide to Fasting


Intermittent Fasting is a fantastic tool for weight loss and healing if done correctly. So many people are confused about fasting. Let’s clear that up… How should you fast, what can you eat and can you drink anything? In this post I hope to clear up some of the confusion and help guide you in the correct way to do fasting. 

“The best of all medicines are rest and fasting”  Benjamin Franklin 

“I fast for greater physical and mental efficiency”  Plato    

Put up your hand if you believed (or still believe) that we need to eat three meals a day plus two snacks in between. I believed you have to eat frequently to keep your metabolism going and that if I didn’t eat every few hours, my would lose muscle mass. 

Millions of people believed, and still believe this flawed dietary recommendation for the last four, five decades. Before the 1970s, when these dietary recommendations were first introduced, people only ate 3 meals a day. Back then there was no obesity, Type II Diabetes and Metabolic Diseases.

Eating three meals and two snacks in between literally means eating the whole day. Why is this so bad you may ask? Well, you have to understand that when we eat all day, we place tremendous stress on our pancreas as well as our digestive system. 

When we eat foods, especially carbohydrate-rich foods, our pancreas releases Insulin. Insulin’s job is to remove the sugar in our bloodstream into our muscles to be stored as energy. Eating 5 times a day means your pancreas needs to release Insulin every time you eat. Repeat this pattern day in day out for years and it is no wonder why we see more than 1 out of 3 people in Western Countries who are Insulin Resistant and Pre-Diabetic. 

Keto Improve Insulin Sensitivity And Blood Sugar Levels

We see now that intermittent fasting has no impact on muscle mass when following a well-balanced Keto Diet. In fact, you will experience amazing physical and mental benefits. The American Journal of Clinical Nutrition explains numerous benefits to fasting, including improved insulin sensitivity, decreased blood pressure, reduced free-radical damage to cells, and weight loss. 

Most people think that fasting is an impossible task. I get that… if you are a carb-burner and are used to having carbs with your meals, you will experience cravings caused by insulin spikes and dips. However, if you are in Ketosis and fat-adapted, fasting comes naturally and you just don’t experience the constant need to eat. Without even planning to fast, I will not feel hungry until two or three in the afternoon. Doing a twenty-hour fast is basically my every day.

In this post, I mostly cover fasting and intermittent and multi-day fasting. If fasting appeals to you, you should also take a look at my post on the Protein-Sparing Modified Fast for accelerated weight loss. 


Think about it, our ancestors didn’t have an 8:00 am breakfast, lunch at 13:00 and an 18:00 dinner. Especially not the snacks in between. They went through cycles during which food was either abundant or very scarce. This obviously contradicts the idea that your metabolism will slow down and cause you to gain weight if you don’t eat 5 times per day. In fact,  I will even argue that intermittent fasting is more effective at reducing insulin resistance than calorie restriction. 

My hubby and I practice intermittent fasting almost every day of the week. As you follow a Keto Lifestyle, intermittent fasting will become natural over time as you become less hungry throughout the day; eventually eating only 2 meals (or sometimes even just one). Compressing your eating window (the time of the day during which you consume calories) really does come naturally for those on a Ketogenic Diet.


It is almost by default that people start fasting when they follow a Ketogenic Diet. As you reduce the carbs, your body starts producing Ketones, which become the preferential source of fuel. As long as you have body fat, your body can produce ketones, which means in the absence of increased Insulin, you just never get hungry. 

More importantly, elevated Insulin is the enemy of fat loss. Remember, Insulin is a storing hormone, and it makes it almost impossible for the body to use fat for fuel when, in fact, Insulin causes the body to store fat. In the image below, I give you a graphical explanation of what causes elevated Insulin. You will see that carbs are the biggest culprit, but even protein and fat can cause elevated Insulin. 

Rz Bnkftmkymillr3Wnq7Fgrlw9Wamcpce 9Fsh4Ljncmhpeuekndb J4Lgy46Meqhtmndcd1Ly7Kbzrdlhtvh0G8W5I6Vtjoue4Hqvohwkvirmoqeeo2Rfjs8Y Ac4Owu72F4Ve | Lean Fit Keto

Keep in mind most people eat three main meals with snacks in between.  Eating this way constantly elevates Insulin levels, which limit the time your body uses fat stores for fuel.

So, if you eat three meals a day with these snacks in between even if these meals would be low carb meals,  it still elevates your Insulin, which means you rarely tap into your fat stores. This is where intermittent fasting is such a powerful tool. Intermittent fasting not only helps to burn more fat but it has a whole lot of health benefits too.

In the image below, I show you what the insulin response would be if you eat three meals a day in a 12-hour window. 

M A3Swha Ym8Lmgj4I74Mxiqabw2Uig7Eu1Xs6Pam9Kgvujmtqov8 7Slbcg8Vkvxy7Ozwk4Xzmr3A1Zuftebux5Mpybshbo1I47L Andn1Qqmh5G Nhruf8Kg4Ojhd6M55Gqkqd | Lean Fit Keto


Intermittent fasting is a profound tool where you cycle between periods of eating and fasting. The most common IF protocol people on a Ketogenic Diet follow, is called the 16:8 protocol. In this protocol, you would fast for 16 hours and then eat during an 8-hour window. Or, the next level of IF protocols would ba a 20:4 protocol. And, one step further from 20:4 would be something called OMAD (One Meal a Day).

When you compress your eating window to 6 hours or less you are creating a smaller time interval in which Insulin is elevated which makes a much larger time frame each day during which Insulin is low. It is in these times of abstaining from food that your body can use stored fat for fuel (lipolysis). The image below shows there is no response on an intermittent fasting day. 

Ix1Qrpcfm5Mxyhpiweumobe H9Extxjq343Ytlexpts3Nwde1Lsltks9S63Wei08Pwxizimtgvgmxj8Ow1Qgdz6Tbhgp7Ds Eywflujbht8Yfjwkmh 77Rsapyymmxroguw02M0 | Lean Fit Keto




The idea behind a morning fast is to benefit from the human growth hormone and glucagon dominant state – also called a fasted state. The fasting benefits are amplified for people who do a cardio workout in the morning. Morning fasts keep the fat-burning hormone, human growth hormone, high. Remember, when you eat, Insulin rises, which pushes growth hormone down. If you want to burn fat, skip eating in the morning and do your morning workout in a fasted state. Here are some tips for a morning fast: 

  1. Have a cup of black coffee. Uunless you have anxiety, adrenal fatigue or a thyroid disorder, caffein can increase fat-burning.
  2. You can also drink tea also black of course because cream will break your fast.
  3. Water is allowed.
  4. Ideally, you don’t want to consume any calories during this fasting window. However, if you stick to under 50 calories of fat, it should generally not break your fast.
  5. It is also beneficial to take amino acids such as L-carnitine (3000mg) upon waking, amino acids help shuttle triglycerides to the mitochondria where fat is burned. 


The evening fast works well for people who do not exercise early in the morning. Eat your breakfast and lunch and then fast until the next morning. 


The ideal fat-burning zone, or for intermittent fasting to be effective, an 8-hour fasting window is best. A smart way to combine the strategies of a morning and evening fast is to have your last meal no later than 3 pm. For the rest of the day and upon waking, you will only consume calorie-free liquids such as water, tea and coffee ( stick to decaf coffee if you have adrenal or hormone issues). A great tip that I learned from Maria Emmerich’s book KETO, is to take L-carnitine first thing in the morning. Ideally, you want to go for a cardio workout of about 30 minutes, and then you can break your fast around 10 am. This approach means you have 18 hours between meals. Of the 18 hours, you are awake for 10 of those hours. And, with the extra workout in a fasted state, this method is highly effective to accelerate fat loss. 

Tip: Regardless of which method you choose, make sure to stop eating at least 3 hours before bed, because eating later in the evening can lead to weight gain and impaired fat metabolism


I believe that the only time it is appropriate and beneficial to fast is if you follow a Ketogenic Diet and you are fat-adapted. Intermittent fasting, when you are in a state of Ketosis (when the body uses FAT for fuel and NOT carbohydrates), allows the breakdown of stored body fat when you fast. It takes a minimum of 72 hours, or 3 days of carbohydrate restriction, to transition your body from using glucose for fuel to using Ketone bodies (for some people that were heavy carb-eaters it can take up to 10 days to transition from a carb-burner to a fat-burner). 

Getting into Ketosis is the first part. Now the aim is to become Keto-adapted. Once you are Keto-adapted you will start feeling as if you can easily skip breakfast. This is is a good sign that you are ready to try Intermittent Fasting. My clients who follow my 6-Week Keto Coaching Program go through 3 different phases. The first phase, which is the two weeks, are focused on getting into Ketosis, the second phase is focused on Keto-adaptation which is geared towards deepening the body’s ability to burn fat. One of the tools we use is fasting; Intermittent Fasting and Protein-Sparing Modified Fasting. If you want to read more on Protein-Sparing Modified Fasting, click here

It is crucial to be keto-adapted first before attempting Intermittent Fasting. If you do Intermittent Fasting while still eating carbohydrates, and the body is still programmed to use carbs for fuel, it can be counterproductive to weight loss progress. Fasting for an extended period outside of a strict Ketogenic Diet can promote muscle loss or wasting and metabolic damage. When the body is forced to fast 12 hours or more (beyond fasting while sleeping) and is using carbohydrates as fuel – the body will go into starvation and thus start breaking down muscle to convert to energy. 


If you have not programmed your body to break down fat for energy through the Keto Diet, your body will mostly turn to breaking down muscle instead of fat. On a carbohydrate reliant energy system, it is necessary to eat every three to four hours and to have your first meal within an hour of waking. This is necessary to regulate blood sugar, prevent cravings and prevent muscle mass breakdown. This is a way for the body to conserve energy when it is “starving. Merely reducing calories such as Intermittent Fasting on a glucose-dependent energy system will break down muscle mass and reduce the number of calories burned at rest. We understand that muscle is “expensive” and by not feeding the body regularly, the body will choose to break muscle down. Muscles form part of the “engine” that burns calories, if you break down muscle, you, in essence, make the engine smaller that is responsible for burning calories. 


  • Intermittent fasting leads to weight loss by increased fat utilisation. It should be clear by now that Insulin increases fat storage. This happens because Insulin upregulates (or increases) lipoprotein lipase, which is a fat-storage promoting enzyme. But, when you are fasting, it decreases the activation of this fat storage promoting enzyme. 
  • Intermittent fasting with a Ketogenic Diet is also said to promote the production of leptin, which sends signals of satiety cues to the brain. Making it a powerful tool for reducing cravings and appetites. 
  • Intermittent fasting can promote insulin sensitivity and reduce fasting blood glucose and prevent Insulin Resistance while reducing inflammation. Insulin is drastically reduced in a glucagon dominance state. When Insulin is reduced, it can’t cause inflammation, which is associated with chronic pain, Fibromyalgia, Heart Disease, Asthma and Diabetes. 
  • Intermittent fasting reduces blood pressure. Blood pressure increases as insulin increases. Insulin is also responsible for storing magnesium, but as you become insulin-resistant, you cannot store magnesium and is simply wasted in your urine. Magnesium has muscle and neural relaxing properties; if magnesium levels are low, your blood vessels constrict rather than relax, which raises your blood pressure and decreases your energy levels. 
  • Studies have also shown fasting to have a positive impact on cognitive function and memory. Some studies even suggest that intermittent fasting can break down plaque formations in the brain aiding to reduce Alzheimer’s disease risk!
  • Fasting leads to a longer life. Studies show that the body can reset the entire immune system with a 72-hour fast. Fasting allows specific cells to live longer because it takes a lot less energy to repair a cell when to divide and create a new one. This is also called autophagy – which is the body’s process for breaking down old and failing cells and building new ones. 
  • Fasting reduces cancer. Fasting cleans out damaged mitochondria and switches on certain genes that repair specific tissue that would not otherwise be repaired outside a fasted state. Fasting decreases oxidative damage and also increases our immune response. 

Fasting can be an excellent tool for healthy ageing support and accelerated weight loss once an individual has committed to a ketosis diet! 


Longer fasts are really used for therapeutic reasons – It allows your body the opportunity to focus on repair activities when it is not taxed with the digestion of food. This process is known as Apoptosis; which increases when longer fasts are done correctly. Apoptosis is a powerful tool for reversing ageing and disease as it kills off the failing, ageing and diseased cells – also called programmed cell death. This is why longer fasts should always be part of a cancer treatment regime. In fact, one study showed that fasting during chemotherapy reduced the side effects and helped protect healthy cells against the therapy. 

When doing a proper long-term, water-only fast, you do not take any calories. You want to get into a state where your body doesn’t have to use any energy for digestion and can focus all its energy on repairing.  

I would always recommend adding electrolytes to your water for the first couple of days( 4 grams of sodium and 4-5 g of potassium) or drinking a bone broth.

The real magic of Apoptosis starts to kick in when your glucose levels fall below your ketone levels. This drop usually happens around the 5th day of a water-only fast, for example, your blood glucose could drop to maybe 3.3 mmol, and your ketones can rise to 4mmol. 

The second book I read when I started keto was The Complete Guide to Fasting by Dr Jason Fung and Jimmy Moore. It was the natural progression for me, as I became fat-adapted, to seek to understand everything about fasting. From this book and some other resources, I learned that it is highly beneficial to do a 5-7 day, water-only fast, once or twice per year. Doing this longer type fast should be more than enough to get all the age-reversing benefits. Anything longer than a 7 day fast does not necessarily mean more benefits.

Most people will do a 16:8 fasting protocol almost on a daily basis. This is what I do mostly. Then, I do a 24 hour fast once a week and a 36-hour fast once every three or so months. It took me a long time to progress from 16:8 to doing a 24 hour fast. For my clients new to keto, I usually let them fast for 16:8 for 2 to three weeks before we attempt a 24 hour fast two to three times a week. Once you can comfortably do a 24 hour fast two to three times a week, you can continue to do this protocol to speed up weight loss.

How To End Your Longer Fast

It is important to note that after a proper long fast (that is a fast of more than 24 hours), follow the fast with proper refeeding immediately. If you have done the fast correctly and your body killed off and removed ageing and failing cells, you should now rebuild lean mass right away. You can do this by increasing your typical protein goal for a few days, which will give your body lots of amino acids to rebuild the muscle that was lost. I would suggest that for the first 4-7 days after a long fast that you increase your protein to 2g of protein per kilogram of lean body mass. 

Fasting is supposed to be a very natural event for our bodies, and, sadly, we have neglected this habit. With the fantastic therapeutic properties of fasting, I encourage you to get to it, start fasting and then refeed properly. 

With one last word of caution on fasting. Fasting should come easy. You should never, under any circumstances, do fasting and feel stressed or ill while fasting. This can be a stressor to your body and not have the desired effect fasting is meant for. Take your time to progress and if you don’t get it right the first time or even the second time, wait a few days and then try again. Everyone can fast and should fast for all the health benefits mentioned above. I find that it is mostly a mental battle when people attempt fasting the first time.

Be patient and be kind to your body and you will get there.


Check out my latest posts and recipes

Berry Cheesecake3


With the festive season coming up, many people are worried that they will struggle to stay in ketosis over the holidays. In this post, I want to add some things that may help, not only stay committed but also make a huge impression on your guests.

Read More »

Keto Casserole Recipes

As soon as the temperatures start dropping, clients start asking for casserole recipes in their meal plans. Here is a roundup of my top Keto go-to Casserole recipes.

Read More »
Keto Macadamia fudge


This Keto Macadamia Fudge is absolutely divine! Very easy to make and perfectly okay to have if you are feeling like having something sweet without the guilt.

Read More »
Keto Carrot Cake1


Keto Carrot Cake? Yes! The moment one says carrot cake, people will say “but that’s not keto”. Even though carrots are higher in carbohydrates, this Keto Carrot Cake only contains one cup of grated carrots, and a single serving comes to less than 6 grams of carbs.

Read More »
Keto Granola


I like to add protein powder to my granola recipes. It’s not only a great way to add different flavours to the granola, but it adds a little protein to!

Read More »