Low Carb Intermittent Fasting is an effective dieting technique but perhaps not for the reasons most of us have heard previously.
In the following article, we'll show you how to get started with intermittent fasting and address some of the most common objections and added health benefits associated with it.
What is Low Carb Intermittent Fasting
Let’s quickly cover what low carb intermittent fasting is and what it isn’t.
First up remember low carb dieting and intermittent fasting are just tools in your arsenal you can use to lose weight. Neither are particularly new concepts and have been around in one form or another for some time. Just because it has proven successful for others doesn’t mean other weight loss methods are any less valid.
Secondly, LCIF (low carb intermittent fasting) is not about starving yourself of carbohydrates and calories as whole. Studies have shown that eating too little e.g. creating an unreasonable caloric deficit over an extended period will only serve to slow your progress. Your body is extremely complex and is always trying to reach a state of homeostasis and will make adjustments to any form of caloric restriction by altering your metabolism.
LCIF is also not a diet in the conventional sense. LCIF is mostly based on meal timing and reducing your intake from carbohydrates. Specifically, you are consuming a diet low in carbs during a ‘meal window’ and fasting for the remaining hours of the day. Depending on your approach, the ‘eating’ window may be anything from 8 hours or less.
The most common method of LCIF is the 16/8 method, which means you are fasting for 16 hours and consuming your calories during the remaining 8 hours. Most people practice this method by abstaining from food after 8:00 p.m. They will then skip breakfast and consume their first meal at 12:00. In case you are wondering, yes, the hours you sleep also count as fasting hours. Based on a regular person's sleeping habits most of us already fast for up to 8 hours every day.
Fun fact, the word breakfast means to break the overnight fast by consuming food e.g. break > fast.
If undertaking a low carb intermittent fasting program, you may not be eating less overall. In fact, for some, it may prove to be difficult to fit in your desired amount of calories in your allocated ‘meal window' to begin with.
To summarize, you can consider LCIF as cycling your food intake to consume calories at optimum times rather than reducing your overall calories and ensuring you are not taking in too many calories from Carbohydrates.
Does Low Carb Intermittent Fasting Help You Lose Weight?
In short yes, it’s an effective method to lose weight, and you won't find many people arguing that it doesn't work. I’ve been testing LCIF personally while incorporating a caloric deficit of around 400 calories per day. When compared to other approaches, fat loss doubled over the same period. That's fairly significant!
Will it work for you?
The best fat loss methods are the ones we can sustain. Can you sustain an LCIF approach to weight loss? Most people report some hunger early on but as the body adjusts e.g. after approx. 2-3 days those same hunger pains begin to diminish making it sustainable for most people.
Why Does Low Carb Intermittent Fasting Work so Well for Weight Loss?
Our bodies are programmed to burn Carbohydrates as our primary fuel source. Once consumed Carbohydrates are converted to Glucose in the blood stream. Glucose is the number one form of energy for our cells.
Excess Glucose is converted by the liver to Glycogen (the stored chain form of Glucose) and retained in the muscles and liver; it's then broken down to Glucose again if required by the body.
The liver can hold about 100 Grams of Glycogen while our muscles can hold approx. 500 Grams. Additional Glucose is broken down to lipids and stored as body fat.
Stored Glucose is available as an energy source for anywhere between 6 - 12 hours. Most of us are topping up that Carbohydrate supply through the day fairly regularly. Our Glucose levels are getting replenished regularly as a result, and the body continues to use these sources as our primary energy source and doesn’t need to dip into our stored body fat reserves.
Because of this, our blood stream contains our quickly available energy while our fat tissue holds energy sources that are better equipped to sustain us over longer periods when food isn’t readily available. If you practice low carb intermittent fasting, however, your body is restricted of glucose and therefore, must use another fuel source for energy, body fat.
What this means is you are training your body to increase production of the enzymes responsible for burning fat. Additionally, you are training your body to minimize the enzymes responsible for using carbohydrates as a fuel source.
Our bodies are extremely well engineered, when carbohydrates are unavailable the body starts looking to body fat as a fuel source. The body's least preferred energy source is muscle tissue.
LCIF is not a switch you flick on and off, though. If you undertake LCIF for several weeks, your body will become more efficient at burning fat as an energy source, and your results will only begin to improve over time.
The Most Effective Benefit for Weight Loss
While the benefits above are all well documented, their effects on weight loss are not as large as often reported. There is no getting around the fact that the largest benefit overall when undertaking an LCIF approach for weight loss is the ease of adherence for some. Many people find a diet with a high amount of healthy fats compared to carbohydrates more sustainable despite fat being considerably more calorically dense.
When used in combination with intermittent fasting LCIF is an effective strategy as IF typically results in caloric reduction simply due to minimising the eating window.
What Happens to Your Body when Fasting:
Here’s a snapshot of what your body experiences during a fasting period.
- Your body will utilize its existing blood sugar (glucose).
- Insulin levels will drop. Lower Insulin levels lead to less body fat.
- Growth hormone production increases by as much as 500%
- The central nervous system will send the hormone ‘Norepinephrine’ to your fat cells which help the body break down stored body fat into fatty acids. Once broken down the fatty acids that are more readily available as an energy source.
- Your body may enter Ketosis (a process where your body will start breaking down stored fats for energy due to insufficient glucose being available).
- Fat loss begins to become more consistent.
Other Health Benefits:
There are numerous associated health benefits with Low Carb Intermittent Fasting. We've listed some of these below:
May lower the risk of type 2 Diabetes
In a healthy person, the body will convert Glucose from the food we consume into energy, which is the primary function of the hormone Insulin. People with diabetes have trouble producing Insulin or cannot produce it in sufficient quantities. So instead of being converted to energy, Glucose remains in the blood stream, elevating blood sugar levels.
LCIF has been shown to reduce blood sugar levels naturally and reduce insulin resistance. While more proof is required, LCIF does appear to be of benefit to those with Diabetes.
Not only does Low Carb Intermittent Fasting hold enormous benefits when it comes to fat loss it is also thought to be of benefit for increasing muscle mass, or retaining muscle if unable to get the gym as regularly over a given period, here’s why:
Clinical studies have shown that fasting can elevate human growth hormone levels (GH). Further to add to this point, Glucose is known to suppress GH. GH production increases when fasting which can assist with Protein synthesis and fat metabolism. In the study referenced above the evidence indicates that fasting results in amplification of GH secretion.
Increases Brain Function
Fasting is similar to weight training in that it is more or less challenging the brain to respond to the stress you are putting it through. Fasting, however, does not cause problems for our mental acuity, in fact, on the contrary, our brains are very much up for the challenge and respond in a positive way.
Protein production is shown to increase in the brain which in turn strengthens the synapses and promotes neuron growth. Fasting is also proved to trigger the production of numerous chemicals in the body that promote neural health.
In the short term fasting also increases mental acuity, which is most likely a response mechanism from earlier times when we were required to hunt for our food. In general, terms if you are hungry your mind is more alert.
Our bodies are constantly repairing and replacing cells. When we are eating regularly, our digestive system is at work, and cellular repair is slow. Cellular turnover and repair increases when undertaking intermittent fasting as our bodies prioritize cellular repair and turnover during the fasting window.
Improves Immune Function
Intermittent Fasting on its own is thought to reduce damage by free radicals. In most animals, if sick we stop eating and seek out rest and recovery. We do this because we feel ill and therefore, don’t feel like eating but this is also a reaction by the body to restrict the digestion process and redirect our energies toward fighting infection by pooling all its resources into this one area.
To summarize, the key benefit of intermittent fasting is giving the body a break from digestion to focus on areas such as cellular repair which has enormous health benefits.
Is Low Carb Intermittent Fasting Safe?
It is safe. But there are a few things you need to be aware of before starting:
- Eating disorders
If you have experienced an eating disorder in the past such as Bulimia, any form of fasting should be avoided. The fast/feast mentality can be risky as the ‘eating window causes some people to overindulge. Taking in too much food even during your ‘eating window; can have a psychological impact and push someone back towards a pre-existing eating disorder.
- Slow and steady
Your body will need some time to adjust as it does if undertaking IF or low carb dieting on their own, and you shouldn't expect results right away. Start with restricting your low carb fasting window to 12 hours and build up to 16+ hours over time as your body adjusts. For some people eating during a particular block of time can affect their energy levels. When we feel low on energy other aspects of our lives can be impacted, for example sleeping patterns.
You must make sure you are not overeating during the eating window. Just because you fasted for 16 hours doesn’t mean you can eat everything in sight during the eating window as you will put on excess weight.
- Best results come when combined with exercise
Most people who undertake low carb intermittent fasting will benefit regardless but incorporating regular exercise and eating healthier meals will set the ball rolling. Don’t rely on IF alone to take you from fat to fit.
- Balanced diet
You must ensure you maintain a balanced diet. Changing the way we eat can sometimes force changes we might otherwise not consider. Always focus on getting the right nutrients into your diet and consuming plenty of vegetables.
- Caffeine dependency
Black coffee is often associated with Intermittent Fasting and is perfectly acceptable during a fasting period due to its lack of calories (2 calories). Some people may rely on this too much and take in too much caffeine. Excess caffeine can be detrimental to sleep and cause health issues such as:
- Dizziness and headaches
- Irregular heartbeat
I’d also recommend the following groups of people steer clear of LCIF or at the very least consult with their doctor before considering it:
- Mum’s to be
- Low blood sugar and Insulin resistance conditions. Intermittent fasting and low carb dieting in general are thought to be of benefit to people living with Diabetes but it’s best to consult with your doctor first.
Common Myths and Objections to low carb Intermittent Fasting
A lot of misinformation surrounds LCIF, from the sensible to the downright strange. In most cases, the largest false assumption people make is that it is dangerous.
The reason low carb intermittent fasting is not dangerous is the fact that the human body can survive without food much more efficiently than we give it credit for. Naturally, if you go 2-3 days without water you will become dehydrated and eventually die, however, the human body can survive without food for extended periods.
In fact, Gandhi, at the age of 74 maintained a hunger strike for 21 days without any reported lasting ill effects.
The remaining myths and objections focus on topics such as muscle wastage, metabolic damage, and breakfast being the most important meal of the day. I’ve addressed the most common of these below:
You will lose muscle
In our article on how to lose body fat and retain muscle I mentioned, I’m not a big believer in eating smaller more regular meals to maintain consistent blood sugar levels and assist muscle synthesis. Research backs this up fairly conclusively.
In fact, it appears that the opposite might even be true. Growth hormone production has been shown to increase while fasting. Increases in growth hormone lead to greater fat burning and muscle growth. Recent studies are turning modern conventions such as breakfast is the most important meal of the day on its head.
During your eating window you are expected to consume all those calories, but can’t we only utilize 30 grams of Protein per meal?
This myth comes from the bodybuilding world and is regularly misquoted, concerning how much Protein your body can use, as opposed to just muscle synthesis. When it comes to building muscle, tests have shown that 30 grams of Protein showed significant benefits to muscle synthesis. When the same tests are conducted with increased Protein, muscle synthesis does not increase.
As a result, the bodybuilding world proclaims the fact that anything more than 30 Grams of Protein per meal is excessive and doesn’t help build muscle. That’s all well and good when it comes to building muscle (the amount of Protein in this context is disputed) but we utilize Protein for far more than just muscle synthesis. Protein is an essential macronutrient and helps with a range of beneficial processes our body undertakes including rebuilding your organs, muscles and building enzymes and hormones.
To summarize, 30 Grams of protein per meal may be optimal for muscle development, but the body uses protein for much more than muscle development.
Isn’t breakfast the most important meal of the day? I thought it was the catalyst to improved metabolism?
This appears to be one of those myths with no real evidence supporting it, that has been adopted and repeated, dogmatically. The fact is eating breakfast does not contribute to weight loss by way of increased Metabolism. There’s nothing wrong with eating breakfast but the fact is there’s nothing scientific to support it making us healthier either. Here’s an extract from one study:
“Daily breakfast is causally linked to higher physical activity thermogenesis in lean adults, with greater overall dietary energy intake but no change in resting metabolism.”
That fact is there isn’t one ‘most important meal of the day’. Eating as soon as you wake up may even be counterproductive to weight loss as a longer fasting window has proven results when it comes to weight loss and increasing metabolism.
I was told eating many smaller meals instead of 3 large meals per day is beneficial to speeding up my metabolism?
The same principles apply here as they do in the argument above. Studies have proven that eating smaller meals more regularly as a means to speed up metabolism are not correct. This study indicates there is no relationship between eating more regularly and any increase in metabolism.
Won’t I lose focus and lack energy if reducing carbohydrate consumption and fasting?
Mental acuity is actually shown to increase when fasting. The fact is when faced with hunger we do become sharper in a sense, and our senses are more highly tuned. When first undertaking any form of low carb dieting it is true some experience what is referred to as the low carb flu. During this time you may experience a lack of energy, cramping and feel a little foggy mentally. Generally this period only lasts approx. 7 days and is thought to be the result of your body switching its primary energy source from sugar to fat.
I’m not sure I can go that long without eating, I’ll be ravenous.
In my experience and from those I have read or observed many people do struggle with hunger, for 2-3 days. Once this short period is over most people, observe a decrease in hunger. In my experience, I found it easier as time went on and could increase the fasting window with minimal effort.
Won’t I have less energy for my workouts if I work out during a fasting window?
Most people can get away with working out less when fasting. I have also spoken to people who claim to have experienced more energy in the gym during their fasting window. On the other hand, I’ve also talked to people who feel too low on energy to workout during their fasting window. Personally, this was also my experience, but it must be said my workouts occurred in the 15-16th hour of my fasting window and I was undertaking a calorie deficit which can also cause this type of reaction.
How To practice Low Carb Intermittent Fasting
Hopefully, by now I have convinced you of the benefits of LCIF. If you are interested in giving this method, of weight loss a try, I have written some recommendations below on how to get started.
There is nothing all that complex to getting started with low carb intermittent fasting. While there are five traditional IF methods available ranging from daily to weekly fasts I recommend getting started using the 16/8 model made famous by leangains.com and incorporating a low carb approach in combination.
The 16/8 Low Carb Intermittent Fasting Method
The benefits of the 16/8 model for weight loss is you are fasting every day which is far less challenging than having to fast for an entire day or eat just one meal per day as some fasting regimens recommend.
Remember it's best to ease into practicing LCIF as your body will take a little while to adjust. For this reason, I recommend starting with a 12-hour fasting window and only redicing your carb intake slightly before and building up to 16 hours and reducing carbohydrate intake further. The best way to go about this is to start your fasting period at night and incorporate your sleeping hours into your fasting window.
For example, commence your fasting window after your evening meal e.g. 8:00 PM. You would then fast until 8:00 AM. consuming your food in this way may be standard practice for some already but if you are typically snacking into the night or having an early breakfast try to start with a 12-hour window with slightly reduced carbs. After a few days push out your first meal to 10:00 am, reduce carbs further and eventually make your first meal at 12:00.
I like having my last meal at 8:00 PM rather than later e.g. 10:00 PM. Anything later than this and you are in a sense fueling up the car and then parking it in the garage rather than utilizing the fuel you just added (sleep).
Tips to Help you Through the Fasting Window
Most people will find they adjust quickly, and hunger pains won't be a big deal, but there are some tips you can use to make the fasting period easier to get through. I've listed some of the best tips below.
Zero Calorie Drinks
You can consume zero calories drinks without technically breaking your fast as you are not consuming calories. Just remember adding milk or sugar to your coffee means you are no longer drinking a zero calorie drink. I recommend avoiding heavily processed drinks as they mostly contain harmful additives to replace sugar.
Start Your Fast After Your Evening Meal
It makes sense to incorporate your sleeping hours into your fasting period. After all, it's hard to experience hunger pains if you are asleep. It makes life even easier if you ensure that last meal of the day is a big one.
Drink Lots of Water
There are many reasons why everyone should increase their water intake. When it comes to fasting, water will help you from the feeling of having an empty stomach and avoiding hunger pains.
If you are attempting to burn excess fat while working out in caloric deficit you will be forcing your body to utilize body fat for energy. However, if you are more interested in your performance in the gym as opposed to burning fat, it's best to workout during your 'eating window' so that you have the necessary energy to perform at your best. I tested working out during the final hour of my fasting window and personally found it difficult to perform at 100%
Keep Yourself Occupied
Many people reported feeling more alert during their fasting period. We've explained the reasons for this above but to take advantage of this new found alertness; it's smart to focus on your most demanding tasks for the day during the fasting period. This also has the benefit of keeping your mind from focusing on potential hunger you may otherwise be feeling.
Starting your fasting period at 8:00OPM will suit most people but if you are a shift worker, for instance, be sure to adjust the fasting window to suit your schedule.
Eat Lots of Protein and Healthy Fats
Eating 30 grams of protein at every meal will help control your appetite. It also has the added benefit of helping you build muscle and repair your body. Avoid cravings and eating unhealthy during your eating window, stick to solid foods that fill you up (satiate) and keep you feeling full for hours. While fats are more calorically densethan carbs they are more satiating and will help you feel fuller for longer.
As you can see low carb intermittent fasting is effective for weight loss. There are numerous health benefits associated with it and in all reality, it isn't very difficult once you have adjusted to it. The tips in the section above should help you get started and help guide you through the more difficult initial 7 days when you will feel hungry or low on energy during the fasting window, particularly in the mornings. It's also important if you undertake a LCIF regimen that you stick it out for at least 30 days and give your body the required time to adjust and start melting away that unwanted body fat. Best of luck!