Table of Contents
- What is Intermittent Fasting?
- How Can Intermittent Fasting Improve My Daily Life?
- 5 Different Methods of Intermittent Fasting
- Stages of Intermittent Fasting: By the Hour
- How Intermittent Fasting Can Help You Reach Your Weight Goals
- Is there anyone who shouldn’t fast?
- Getting Started
In today's world, we find ourselves almost constantly surrounded by food. Knowing when and what to eat is a never-ending struggle, filled with tough decisions and efforts to balance long-term and short-term goals. This is why diets like intermittent fasting have become more popular over the past few years.
A growing body of evidence suggests that intermittent fasting (IF) has a large number of health benefits, including weight loss, improved insulin response, and lower blood pressure. But is it right for you?
If you've ever wanted to try IF, you're in the right place. In this article, we break down everything you need to know - what it is, why it works, and how it can positively affect your health.
What is Intermittent Fasting?
In the past, ancient hunter-gatherers faced a harsh fact: there was no such thing as refrigeration or 24-hour supermarkets. To survive and make it through occasional periods of scarcity, our ancestors evolved so that they could function for extended periods without food. Today, we have it easy in comparison - food is available around the clock, but in many ways this has backfired by affecting our sense of hunger.
Intermittent fasting (IF) is a dietary pattern that involves cycles of fasting and eating. What IF doesn’t do is specify which foods you should eat, but rather when you should eat. In general, people practice IF by restricting their food intake to certain hours of the day or days of the week. The main goal is to ease your body into the practice rather than trying to drastically change your habits with an all-or-nothing approach.
One of the best things about intermittent fasting is that you get to decide how long you want to fast, and what type(s) best fit your lifestyle and goals.
How Can Intermittent Fasting Improve My Daily Life?
People are becoming increasingly aware of intermittent fasting as a strategy to lose weight and gain back control of their lives, but it has other, often overlooked, benefits.
If you’ve ever felt like you need a break from all the food-related decision making in your life, intermittent fasting could be for you. While intermittent fasting won't necessarily simplify every aspect of your life, it can help to reduce the number of decisions you make each day about what to eat. This saves time in the kitchen since you don’t have to cook or clean up as often, which can help you focus more on other areas of your life.
Fasting works with every diet and schedule. And best of all, it can be done anywhere. You can fast at home, in the office, or even squeeze some in on vacation. You don't need to go buy specific foods or any fancy equipment. All you need to do is fast for a set period of time and then eat normally for the rest of the day. This is also why some people prefer it to daily calorie counting or other restrictive weight loss plans.
Fasting can help you reset your relationship with food. When you fast, you’re likely to eat less overall. You may find that you’re less inclined to overeat or make impulsive food choices as often. This can lead to long-term savings on both your grocery and medical bills.
5 Different Methods of Intermittent Fasting
There are many different methods of intermittent fasting, each with their own benefits and drawbacks. The best method for you will depend on your goals and lifestyle. So, there’s no need to be strict about it – you can always switch things up if one method isn’t working out.
Five of the most common types include:
1. Time-Restricted Eating
One of the most popular methods is to eat every day but instead of eating any time you want, you’re restricted to certain hours. Hence the name, time-restricted eating.
Some of the most common ways to do this method are:
Only eating between 10 a.m. and 6 p.m. This method involves fasting for 16 hours each day and eating all your meals within an 8-hour window. This is often done by skipping breakfast and only eating lunch and dinner, or by skipping dinner and only eating breakfast and lunch.
Only eating between 9 a.m. and 7 p.m. Same as the above, but with a slightly shorter fasting period (14 hours) and longer eating window (10 hours).
With this method, you fast for 12 hours, then have a 12-hour eating window. One example could be eating dinner before 7 p.m., then fasting until you have breakfast at or after 7 a.m. the following morning.
Research shows time-restricted eating (versus eating whenever you want) can have beneficial effects on improving menstruation in women and reducing weight.
2. Alternate-Day Fasting
As the name suggests, with this method you alternate between days of fasting and days of eating normally.
There are a couple different ways to approach this method. One way is to completely fast for 24 hours every other day. So, if you started your fast at 8pm, you would not eat again until 8pm the following night, and repeat.
Another way is to restrict calorie intake on fasting days to around 500 calories ― or about 25% of your normal intake. On non-fasting days, you would resume your regular diet. Some people choose to completely fast on their fasting days, consuming only water or other non-calorie beverages. Others allow themselves to eat a very small number of calories on fasting days. The best choice is the one that aligns with your needs.
3. 5:2 Method
When we put too much pressure on ourselves to make big changes too fast, we're more likely to binge-eat and fall off the wagon. It's not realistic for many people to cut back on what they eat all seven days. For this reason, the 5:2 approach may work better than cutting calories the entire week.
Essentially, this method involves reducing your calorie intake for two days each week, while eating normally the other five days. For example, you might restrict calorie intake to 500-600 calories on Monday and Wednesday, and then eat normally on Tuesday, Thursday, Friday, Saturday and Sunday. And because you're only fasting two days a week, many find it easier to stick to than traditional diets.
4. Eat Stop Eat (24 hour fast)
The Eat-Stop-Eat form of intermittent fasting involves a fasting period of 24 hours, then eating normally for the next 24 hours. This cycle is repeated 1-2 times per week. Ideally, the days should be spaced out and not consecutive. This cycle can be repeated as often as you like, and it's a great way to give your body a break from digesting food.
5. OMAD (One Meal a Day)
The OMAD diet is a more extreme type of intermittent fasting that involves eating just once a day. This means that you fast for 23 hours each day and eat one large meal, within a one-hour time frame. During this hour, you can eat whatever you’d like.
OMAD may not be a good fit for beginners. If you're interested in trying this method, we recommend that you speak with your doctor or a nutritionist first. They can help you determine if this is right for you and provide guidance on how to safely start and maintain it.
Across the board, intermittent fasting doesn’t necessarily require you to give up any foods or eat less overall – you just need to change when you eat. And because you’re not depriving yourself, you’re less likely to experience the rebound hunger and cravings that often accompany more traditional diets.
Whatever method you choose, the key is to stick to it consistently in order to reap the benefits.
Stages of Intermittent Fasting: By the Hour
If you’re considering trying intermittent fasting, it’s important to understand what's happening in your body hours after your last meal.
During the first four hours after eating, the body is in what’s known as the "anabolic growth phase" - meaning that nutrients are available and the body can use them to build muscle, burn fat, or store them. Your body is using up the energy from your last meal to fuel your daily activities, as well as for cellular and tissue growth.
Right after a meal, your blood sugar levels rise, causing your pancreas to release the hormone insulin to regulate levels. Insulin signals the body to burn energy by pushing glucose (sugar) into cells. Excess sugar is stored for later use in the liver as glycogen or stored in fat cells.
Summary: After a meal, you digest and absorb food into your bloodstream. Then, your pancreas releases insulin to manage the rising glucose levels. Insulin helps store excess glucose as glycogen in your liver. Once your liver’s glycogen storehouse is full, the remaining sugar is turned into fat.
As this phase begins, your blood sugar and insulin levels will start to decline. You'll also experience a drop in your leptin levels - the hormone responsible for telling you you're full. Ghrelin, the hormone that signals hunger, will rise.
In the early fasting state, your body switches from the anabolic to the "catabolic," or breakdown, phase, when all those stored nutrients can now be put to use.
When insulin levels fall, your body will begin burning off your glycogen stores of glucose from your liver. That’s why it’s so important to wait that long between meals so you can keep recycling your glycogen stores. Otherwise glycogen can build up and contribute to fatty liver.
Eventually, your body will run low on stores and start searching for another energy source. A process called lipolysis (fat-burning) begins. This causes the breakdown of fat cells, which are converted into energy. A few hours post-meal, about 60% of your energy will come from the liver’s glycogen storehouse and the other 40% comes from fat burning. At night, this reverses, with 60% of your energy coming from stored fat.
Typically, it takes between 4 and 18 hours of fasting for you to burn through glycogen stores. Your body will start to break down its fat stores even before it finishes using up all the glucose in your system. With this in mind, research suggests that intermittent fasting can help boost your fat-burning abilities!
Summary: A few hours after a meal, insulin levels begin to drop. This signals the body to release energy from glycogen storage sites in the liver and muscle. Fat burning begins.
When glycogen stores are finally depleted, your body will transition into a state called ketosis, where fat becomes the primary source of energy.
Ketones are the natural breakdown product of burning fats. As fat cells are broken down for energy, ketone bodies are created and released into the bloodstream, carrying a number of key benefits.
When your gut has finished absorbing your last meal, your pancreas stops producing insulin. As insulin levels remain low, the amount of glucagon – a hormone that controls blood sugar levels – signals your liver to slowly start releasing the stored sugar (glycogen) into your bloodstream.
It’s during this stage that your body also starts to do something really interesting. It activates a natural healing process known as autophagy. Autophagy helps your cells clean up and get rid of any old or damaged components.
The idea behind autophagy is that the body recycles its cell components to protect against stressors and regenerate healthy cells. To enter this phase, your body requires low liver glycogen.
Summary: During the fasting state, fats take over as a primary energy source. Glucagon levels rise to prevent blood glucose levels from dropping too low. Autophagy begins.
Note: There is not enough data to determine the optimal fasting period. Each individual is different, so it's important to speak with your doctor about the specific fasting method you're using, to ensure you are staying safe.
Measuring Urinary Ketones for Fat Burning
As we discussed earlier, when you restrict or limit high-carb foods, your body runs out of glucose to meet its energy needs and begins to look for alternative fuel sources. This results in the breakdown of stored fat into fatty acids and ketones, which supply most of your brain's energy. Ketone levels are detectable in your breath, urine, and blood while you're in dietary ketosis.
A urine test strip is a convenient and cheap way to determine if you're in the ‘fat burning zone’. They were originally developed for people with type 1 diabetes to check if they're at risk for diabetic ketoacidosis.
You can buy over-the-counter strip kits at pharmacies and supermarkets, as well as online. They are relatively inexpensive and contain 50 to several hundred strips.
If you plan to check your urine ketones regularly, stick to the same time, such as first thing in the morning or several hours after your last meal.
What Is a Good Ketone Level?
If your primary goal is weight loss, aiming for “light nutritional ketosis” when ketone levels reach 0.5 mmol/L-1.0 mmol is a good place to start. A ketone level between 1.5 to 3 mmol/L is said to be optimal.
How Intermittent Fasting Can Help You Reach Your Weight Goals
When you’re used to eating regularly throughout the day, it can be easy to mindlessly snack or overindulge. Frequent eating keeps blood sugar levels high and signals that there is no need to burn any fat. There’s a constant supply of food coming in, so your body just keeps on storing more away. Some people remark that they never experience hunger because they eat so often.
Insulin and weight are irrevocably tied together. Weight gain has less to do with calories and more to do with our unstable relationship with the hormone insulin. When you produce too much insulin, it follows its prime directive to stuff glucose into cells for energy. Excess glucose is stored in your liver first. But the rest is stored as fat.
When you fast, you’re forced to use up the glucose stored in the cells - allowing your body to burn fat for fuel instead. For this reason, fasting can actually increase your metabolic rate. It works as a powerful weight-loss tool on both sides of the calorie equation. Helping to boost your metabolism (increases calories out), while also reducing the amount of food you eat (reduces calories in). By fasting for periods of time, you can train your body to feel satisfied on less food. This can lead to eating less overall and consequently, weight loss.
Many people opt for IF because they're not interested in having to do the daily grind of cutting calories. In many cases, this method has actually proved to be a healthy way to lose weight. According to a 2014 review, intermittent fasting reduced body weight by 3–8% over a period of 3–24 weeks. The study participants also reduced 4–7% of their waist circumference, which indicates a significant amount of harmful visceral fat was lost.
5 Health Benefits of Intermittent Fasting That Will Most Likely Surprise You
The benefits of intermittent fasting go way beyond weight loss. One of the most notable is the fact that fasting can help to improve your overall health and promote healthy aging. Let’s discuss.
Helps kick off cellular repair processes
When you fast, your body is able to rid itself of any waste. This allows your organs to function more efficiently, which gives your immune system a chance to rebuild and become stronger. Intermittent fasting triggers autophagy (the process by which your cells clean up and get rid of any old or damaged parts). So, in addition to priming the immune system, fasting-induced autophagy can also improve cellular resistance to stress and protect cells from damage.
In one recent study, researchers found that COVID-19 patients who committed to regular water-only fasting had a lower risk of hospitalization or death due to the virus than those who didn't.
Can improve insulin resistance, lowering your risk for type 2 diabetes
After you finish digesting your food, one of your liver's most important jobs is to regulate energy in your body. It does this by burning fat and balancing blood sugar, as well as storing precious energy as glycogen (a form of glucose).
A few hours after eating, your insulin levels begin to decrease significantly. But if you continue to eat every two to three hours, you’re creating a constant demand for more and more. When your body becomes resistant to insulin, it doesn't effectively process glucose, leading to high blood sugar levels (type 2 diabetes). It’s also been found that frequent eating can confuse your liver and signal it to release stored sugar, even when your blood sugar is already high. Talk about a vicious cycle.
By improving insulin resistance, intermittent fasting can help lower your risk for developing type 2 diabetes. This is most likely because fasting gives the body a much-needed break and the chance to burn through its glycogen stores. When glycogen stores are depleted, blood sugar levels fall. In one study, fasting blood sugar was reduced by 3-6% and fasting insulin levels dropped by 20-31% over the course of 8-12 weeks.
May be beneficial for heart health
Intermittent fasting can be a great tool to improve your heart health. When you fast, your body is able to burn through stored fat for energy, which can help to lower cholesterol levels and improve blood sugar control. This method has been shown to positively impact obesity, hypertension, and diabetes—all of which are risk factors for heart disease.
A recent study of prediabetic men showed a reduction of systolic blood pressure and diastolic blood pressure after 5-weeks of fasting for 18-hour periods.
In another 2020 study, intermittent fasting helped women with metabolic syndrome. This is a group of symptoms including high blood pressure, high blood sugar, and excess abdominal fat — that raises the risk of heart conditions. When these women restricted their food intake to a 10-hour window during the day, they experienced weight loss, lower blood pressure, improved cholesterol, and fewer blood sugar spikes.
Can improve digestion and poor gut health symptoms
Cycling between periods of fasting and eating allows the digestive system time to rest and repair itself. This means that any digestive issues you may be experiencing can be given a chance to improve. Intermittent fasting also helps reset the body's natural balance of good and bad bacteria, promoting better overall gut health.
Overtime, IF results in improved gut motility, increased nutrient absorption, and reduced inflammation. This is especially important since inflammation is a major contributor to many digestive disorders.
May boost brain health and protect against cognitive decline
Intermittent fasting has been shown to have a number of benefits for brain health, including improved cognitive function, decreased inflammation, and increased protection from neurodegenerative diseases.
The body normally uses glucose for energy, but during IF it switches to using fatty acids and ketones - a change known as metabolic switching. But ketosis is not just about fat burning. Ketones also convert glutamate, the most abundant excitatory nervous system neurotransmitter - to GABA, which helps the brain focus. GABA promotes relaxation and helps balance glutamate which makes up 90% of the brain’s synaptic connections.
Cognitive function may be further improved through autophagy, the stage during which the body clears out damaged cells and recycles their nutrients for use by healthy cells. This process has been linked with improved memory and learning.
Emerging research continues to show how intermittent fasting can stimulate cognitive function by promoting cell repair and helping your brain form new cells and connections. Many people who regularly fast report improved mood and increased clarity of thought, which can in turn benefit your overall happiness.
Is there anyone who shouldn’t fast?
For most people, intermittent fasting is a safe choice. But certain groups should avoid it altogether, including:
- Those under 18 years of age
- People with high blood pressure
- People with kidney disorders
- Those with Type 1 diabetes
- Pregnant or breastfeeding women
- Anyone who is underweight
- Anyone who has a history of eating disorders
- Certain medications
As with any lifestyle change, check with your healthcare provider if you’re not sure that fasting is right for you.
What Are the Side Effects of Intermittent Fasting?
There are a few potential side effects of intermittent fasting that you should be aware of before starting. Common symptoms include:
- Brain fog
- Muscle aches
- Hunger & cravings
- Difficulty sleeping
- Flu-like symptoms
These side effects are usually temporary and will go away as your body adjusts to the new eating pattern. Be sure to listen to your body and make changes as needed. If you're thinking about trying intermittent fasting, it's important to consult with your healthcare provider first to make sure it's safe for you.
First things first, decide which type of IF schedule you want to try. Experiment with the different approaches outlined above and find something that you enjoy and fits your schedule. If you're new to fasting, start with a shorter time frame, like overnight, or 12 hours. Once you're used to that, you can then move on to longer fasts, if you choose. For example, you could start by skipping breakfast one day per week and gradually work your way up.
Just some of the things you have to look forward to in your intermittent fasting journey is that overtime you’ll be able to:
- Decrease the time you spend preparing food.
- Drink more water in between meals instead of snacking.
- Exercise more comfortably without a full stomach.
- Experience the delight of eating when you are actually hungry.
- You’ll be more productive in between meals and feel a great sense of accomplishment.
- You won’t be wandering into the kitchen or your snack drawer every two hours like a starving zombie.
- You’ll experience less emotional eating. Not having a snack to turn to will help you find better ways to deal with boredom, anger or sadness.
Need guidance on how to get started? Head over to How to Start Intermittent Fasting where we walk you through step by step.
Here are answers to the most common questions about intermittent fasting.
What breaks a fast?
All in all, any amount of calories will break a fast. You should avoid calorie-containing drinks or foods during this time.
Can I drink liquids during a fast?
Yes. During fasting hours, you can drink water, black coffee, or tea - with no added sweetener, cream, or flavoring of course. For more information on the best ways to navigate your fast, click here.
How can I replace electrolytes while fasting?
Add ¼ teaspoon of natural sea salt to 1L of your drinking water to get those vital minerals back in your body. Aim to consume at least half your body weight (in ounces) of mineral water. If you want to invest in your health, a liquid electrolyte supplement can be beneficial to optimize hydration.
Can I take supplements while fasting?
Yes, you can take supplements while intermittent fasting! Keep in mind that some supplements like fat-soluble vitamins may work better when taken with meals.
Start your morning routine with your daily dose of liquid ReMag® and ReMyte® to not only replenish key minerals, but to help manage fasting symptoms as well. RnA ReSet Completement Formulas provide their own layer of protection against nutrient deficiencies while fasting, and help the body stay as healthy as possible during this time.
Can I workout while fasting?
Yes. In fact, working out while fasting can help you burn more fat and improve your overall health. However, it's important to remember that you shouldn't overdo it. If you're new to intermittent fasting, start slowly by working out for 20-30 minutes a day. Once your body gets used to the fasted state, you can gradually increase your workout time.
If you're doing a high-intensity workout, it's best to do so during non-fasting periods, so you can eat something before or during your workout. This will help you avoid feeling lightheaded or dizzy.
Will fasting cause muscle loss?
Losing muscle while fasting is a common concern, especially among those who are new to fasting. However, there is no need to worry. Fasting does not cause muscle loss. In fact, research has shown that intermittent fasting may actually be more effective for maintaining muscle mass during weight loss than non-fasting diets. According to a 2011 study, intermittent fasting causes less muscle loss than regular calorie restriction diets.
Will fasting slow down my metabolism?
There's no evidence that intermittent fasting reduces your metabolic rate any more than other diets. The argument against intermittent fasting is that it puts your body into "starvation mode", which prevents you from burning fat and shuts down your metabolism. While it’s true that long-term weight loss can cause you to burn fewer calories over time, this happens no matter what method you use.
A short-term fast can actually increase your metabolic rate because norepinephrine levels increase, which stimulates your metabolism and signals your fat cells to break down body fat. Research shows that fasting for up to 48 hours can boost metabolism by 3.6–14%. However, with longer fasts of 3 or more days, your metabolism can reverse, decreasing instead.
The Bottom Line
Intermittent fasting is a powerful tool that offers a less-restrictive way to improve your daily health and increase energy levels. It’s important to remember that there is no one-size-fits-all approach, the key is to find a method that works for your body and lifestyle. If you’re new to IF, start with shorter cycles and increase the length of your fasts gradually. Always be sure to listen to your body — if you start to feel off, adjust accordingly.