Fasting is an age-old way to support both the body and mind. However strange it may sound, refraining from eating for a few days can actually benefit your body and mind! For many of us, this can be challenging to sustain. Intermittent fasting offers a viable alternative, as it involves fasting for shorter periods. Aside from being feasible, intermittent fasting can be very healthy. Research has shown that it can contribute to weight loss, a stronger immune system, reduced body fat, a lower risk of various lifestyle diseases, slowed aging processes, improved cognitive function, and a fitter body. Discover in this article:
- What intermittent fasting means and entails.
- What intermittent fasting does to your body.
- The 6 key health benefits of intermittent fasting.
- Different intermittent fasting methods to try.
- Useful tips for intermittent fasting.
- How to combine intermittent fasting and juice fasting.
What is Intermittent Fasting?
When you hear the word “fasting,” you might think of ancient spiritual traditions where people refrain from eating for a certain period to achieve a higher state of consciousness. The term might sound strict and radical. For many, completely stopping eating for a certain time is not that simple, especially with busy lives and social commitments. Intermittent fasting has gained popularity in recent years as a more achievable alternative.
What Does Intermittent Fasting Mean?
Intermittent fasting is a way of eating where you alternate between periods of eating and fasting. Instead of fasting continuously for days or weeks (not eating at all), intermittent fasting involves alternating shorter periods of fasting and eating. For instance, you might fast for a certain number of hours per day or not eat much for a certain number of days per week. Research (1) has shown that the timing of your eating and fasting periods also affects the effects of intermittent fasting. You could say that it’s a diet that focuses not on what you eat but when you eat.
How Did the Intermittent Fasting Trend Begin?
Intermittent fasting is a relatively recent phenomenon in the Western world. Various documentaries and books have contributed to its growing popularity in the past decade. In 2012, British Dr. Michael Mosley brought attention to the benefits of intermittent fasting through his documentary “Eat Fast, Live Longer” and his book “The Fast Diet.” Shortly after, Kate Harrison’s book “The 5:2 Diet” followed, and in 2016, Dr. Jason Fung’s “The Obesity Code” became a bestseller, presenting scientifically proven health benefits of intermittent fasting. Substantial research has been conducted on the health benefits of intermittent fasting. Before delving into those benefits, let’s briefly explain the effects of intermittent fasting on your body.
What Does Intermittent Fasting Do to Your Body?
First and foremost, it’s important to know that enzymes in your digestive system break down our food into molecules that eventually end up in our bloodstream. Carbohydrates (especially sugars and processed grains like white flour and rice) are broken down into glucose, which our cells use as an energy source. Anything our cells don’t need immediately is stored as fat in our fat cells. Insulin, a hormone, is responsible for this process. It transports glucose to fat cells and keeps it stored there (2).
When you go without eating for more than 8-12 hours, a “metabolic switch” occurs. As long as we don’t consume calories, our insulin levels decrease, allowing our fat cells to release their stored energy in the form of ketones. These are a more efficient energy source than glucose. When we start burning stored fat, we lose weight. This brings us to the first health benefit of intermittent fasting. Read on!
The 6 Health Benefits of Intermittent Fasting
1. Intermittent Fasting Can Help You Lose Weight
The most obvious health benefit of intermittent fasting is its potential for weight loss. Typically, you consume fewer calories on average. This alone can aid in weight loss. Additionally, intermittent fasting encourages your body to burn fat due to longer periods without quick sugars from recent meals. Scientific research has shown that besides weight loss and lower body fat percentages, intermittent fasting has more long-term health benefits.
2. Intermittent Fasting Helps Prevent Lifestyle Diseases
As your body doesn’t need to focus on processing food during fasting periods, it can allocate time to address other important functions. In our modern society, where many of us eat three times a day and snack late into the evening, our bodies often lack that time. Our evolutionary ancestors had to work harder to acquire food and were more dependent on circumstances than we are today. This often meant longer periods without food, which also has advantages!
More on Ketones
Research (3) indicates that intermittent fasting reactivates certain bodily processes from an earlier era of our evolution. After not consuming calories for over 8 hours, your body starts producing more ketones. After 12 hours of fasting, ketone levels in your body have increased significantly. Ketones are molecules that serve not only as a source of fuel but also as crucial signaling agents for your cells and organs. When your body has over 10-12 hours to digest a meal, it becomes more effective at counteracting cell oxidative damage, repairing or disposing of damaged molecules, and regulating blood sugar levels.
Intermittent fasting thus helps prevent various lifestyle diseases, such as:
- Cardiovascular diseases
- Elevated cholesterol levels
- Degenerative brain disorders
3. Intermittent Fasting Protects Cells and Organs
Ketones play a critical role in processes related to countering cell damage and thereby certain diseases and aging in general. Intermittent fasting prevents damage to cells and organs in two ways:
Fewer calories = fewer free radicals:
Consuming fewer calories leads to fewer free radicals that can damage your cells and contribute to conditions like cancer and cardiovascular diseases. Ketones add to this effect by helping repair and prevent cell and organ damage.
One of the processes activated by intermittent fasting is autophagy, defined as “self-digestion.” During autophagy, cells that are aged or damaged are efficiently recycled or removed (4). Since aging processes are connected to cell damage, intermittent fasting is touted as a way to combat or at least slow down aging.
4. Intermittent Fasting Improves Immunity
Results from scientific research (5) indicate that intermittent fasting makes your body more resilient to external influences. It becomes more resistant not only to free radicals but also to inflammations and viruses.
5. Intermittent Fasting Enhances Brain Function
Intermittent fasting also benefits your brain, where ketones are a significant source of fuel during fasting. As mentioned earlier, ketones help limit damage to brain cells, potentially preventing neurodegenerative diseases in the long term. Even in the short term, this type of fasting has a noticeable effect on cognitive function. For example, animal studies have shown that intermittent fasting positively influences working memory, while human research demonstrated a boost in verbal memory (6).
6. Intermittent Fasting Increases Fitness
Scientific research on young men has demonstrated that intermittent fasting can help burn fat without losing muscle mass, particularly when combined with resistance training. Research on rodents revealed that intermittent fasting increased the endurance of the animals (7). Additionally, intermittent fasting can prompt your body to produce more growth hormone, important not only for strong muscles and bones but also for healthy brain function.
Different Forms of Intermittent Fasting
Various forms of intermittent fasting exist, each with a different ratio of eating to fasting. Here’s a brief overview of some methods to give you a better idea of how intermittent fasting works in practice. To fully experience the health benefits, it’s important to stick to a specific schedule for a certain period of time. Read through the methods and determine which one seems most feasible for you!
The 16:8 Method
The 16:8 method, or the 16:8 schedule, is a popular form of intermittent fasting that many people find manageable. In this method, you ensure that you consume enough calories within an 8-hour window and don’t eat for the other 16 hours. During those 16 hours, you can still drink beverages without calories, such as water and herbal tea (without sugar or additives). This fasting pattern is also known as “daily time-restricted feeding,” and you can repeat it daily. If fasting for 16 hours seems too long to start with, you can begin with a 14:10 schedule and gradually work your way up to 16:8. For women, slightly shorter fasting periods, such as 14 or 15 hours instead of 16, might be more suitable. Remember, everyone is different!
When to Fast?
You can choose when to start your fasting period; for example, skipping breakfast and eating between 12:00 and 20:00, or skipping dinner instead. According to a small study (8), eating earlier in the day and not eating in the evening had several benefits. Participants who ate between 7:00 and 15:00 experienced reduced appetite and still enjoyed the health benefits of intermittent fasting. This schedule might be easier to maintain. This timing had positive effects on participants’ blood sugar levels and blood pressure. In any case, it’s wise to let most of your fasting period occur during the night when you generally don’t eat and require less energy.
The 5:2 Diet
With the 5:2 diet, you eat normally for 5 days a week and significantly reduce your calorie intake for two days a week (for example, Tuesday and Thursday; these don’t need to be consecutive days). There’s a similar fasting method where you don’t eat at all on fasting days. On these days, you can only consume beverages without calories, such as water, herbal tea, and black coffee. You could begin with 500/600 calories on fasting days and gradually transition to not eating at all on those days.
This fasting method follows its name. You alternate between a day of eating and a day (24 hours) of fasting, and you do this over the long term. If you find a full 24-hour fast too much, you can perform this method by consuming, for instance, 500 calories on fasting days.
Intermittent Fasting Tips
If you’re excited about the health benefits of intermittent fasting and want to give it a try, carefully read the following tips. Incorrect fasting can have adverse effects on your health, and there are circumstances in which fasting might not be advisable for you, at least temporarily.
- First and foremost: if you’re unsure whether intermittent fasting is healthy for you, always consult your doctor or dietitian. This is especially important if you take certain medications, have a heart condition, or suffer from Type 2 Diabetes. If you have low blood pressure or anemia/iron deficiency, it’s also recommended to consult your doctor.
- Intermittent fasting is generally not recommended for people with underweight or a history of eating disorders.
- If you’re pregnant, planning to conceive, or breastfeeding, it’s best to avoid intermittent fasting. It might also be a good idea to temporarily avoid intermittent fasting if you experience heavy menstruation.
- If you feel physically exhausted, weakened, or experience significant effects from blood sugar drops, intermittent fasting might not be suitable for you. In such cases, consult a doctor.
- Don’t make your fasting periods excessively long. While extending your fasting periods might be tempting, longer doesn’t always lead to better results and can even be harmful. Stick to the recommended fasting schedules mentioned above.
- Avoid consuming large amounts of unhealthy foods after fasting periods. You might be tempted to reward yourself for your discipline with a heavy meal or fatty snack, but it’s wiser to gently reintroduce digestion with light food. It’s generally beneficial to choose a healthy diet with plenty of vegetables and fruits, as well as unprocessed and organic foods on the days you eat. Additionally, ensure you consume enough protein on eating days—aim for about 25-30% of your total calorie intake to come from protein. This helps maintain muscle mass even during weight loss and can also curb hunger.
- Stay well-hydrated. Since a portion of our necessary hydration usually comes from our food, it’s important to drink extra during fasting periods. Aim for at least 2-3 liters of fluids a day, preferably water or herbal tea.
- Listen attentively to your body, especially when you’re new to intermittent fasting. Feeling slightly hungry, fatigued, or irritable initially is normal. If these sensations persist or worsen, it’s wise to stop fasting. If you feel truly dizzy, ill, or so unwell that you can’t carry out your daily activities, cease fasting. Even if you feel relatively fine, having a healthy snack on hand for sudden light-headedness is advisable.
- Keep in mind that it might be more challenging to engage in intense exercise on fasting days. Light activities are more suitable.
- Combine fasting with activities that distract from any hunger sensations and help you relax. Examples include (gentle) walks, yoga, meditation, listening to podcasts, reading an inspiring book, or taking a relaxing bath.
- Ensure you get enough vitamins and minerals. Consuming fewer calories might make it more difficult to get the right amount of nutrients. Drinking fresh, organic vegetable juice is a natural way to boost your intake of vitamins and minerals.
Intermittent Fasting and Juice Fasting
As you’ve learned, intermittent fasting offers many health benefits. It can aid in weight loss, shield against various lifestyle diseases, slow down aging processes, enhance your immune system, boost cognitive function, and contribute to a fit and strong body. Juice fasting with organic vegetable juice can also offer health benefits. Juice fasting is a way to receive extra vitamins, minerals, and antioxidants. Additionally, it serves as a tool to make healthy changes to your diet. At Sapje, we offer specialized detox programs for this purpose.
Combining Intermittent Fasting and Juice Fasting
It’s entirely feasible to combine intermittent fasting and juice fasting. For example, if you opt for the 5:2 diet, where you’re allowed around 500 calories on fasting days, you could have juice on those days. This way, you still get a variety of healthy nutrients while providing your body with some support. Whichever fasting method you choose, always pay attention to your body. Best of luck!