Throughout history, physicians and healers have used fasting as an effective way to treat and heal various ailments. From the 5th century BC, the founder of modern medicine, Hippocrates, recommended abstinence from food for patients suffering from certain illnesses. Wellness has come a long way since Ancient Greece, but intermittent fasting has remained an essential therapy and way of life throughout the centuries. Today, researchers are beginning to uncover exactly what happens to our bodies when we fast, and how it can impact our metabolism, hearts and brains.

The cells in the body are like parts of a car. As they age, certain subcellular parts need to be repaired or replaced. The purpose of fasting is to set in motion a process of cell regeneration and toxin cleansing called autophagy, which plays a vital role in helping us live longer.

The accumulation of older, damaged cells may be responsible for many of the effects of aging. For this reason, autophagy should be routinely activated. Autophagy breaks down and recycles these cells so that the body can start the process of renewal, where healthy tissues and cells are created. But this can only work if old cells are discarded first.

If we eat regularly throughout the day, our bodies never get the chance to remove unwanted cells, because we can’t absorb new materials for new cells and at the same time break down defective parts. So fasting for certain periods is essential to encourage the autophagy process.

Research has shown that when animals and people eat as often as they please, autophagy is severely restricted.

One of the most exciting things about intermittent fasting is that it may help us live longer. Several studies of rats have shown intermittent fasting could help extend their lifespan. In one study, the effects were dramatic: where rats fasted every other day, they lived on 83% longer longer than the rats who didn’t fast.

In most cases, intermittent fasting leads to reduced caloric intake throughout the day. You still get the nutrients you need, but you simply eat fewer calories, making it easier to shed weight. Since you’re reducing the times of day during which you eat, or lowering your caloric intake during certain days of the week, it becomes much easier to lower your overall calorie count.

Another reason intermittent fasting is part of a successful weight-loss program for many people is that it’s also effective at reducing the amount of fat in your body. With IF, you’ll find that going for an extended period without eating doesn’t send you into starvation mode. Rather, it lets you consume calories that are available in the form of stored reserves of fat. As such, when you follow an intermittent fasting plan, you force your body to burn fat without putting in any extra work.

These are simple and effective concepts. Intermittent fasting helps you limit the calories you’re consuming, and burn more fat and calories than you would with a more traditional diet.

Intermittent fasting can help improve metabolic attributes that help to keep the brain healthy. This includes helping with insulin resistance, managing blood sugar levels, reducing inflammation and easing stress.

Several studies have shown that intermittent fasting can help in the growth of new nerve cells, which improves brain function. Fasting can also help to increase neurotrophic factors, which are brain-derived substances that control cell proliferation in the nervous system. This effect is crucial during cell regeneration. When the brain is deficient in neurotrophic factors, it has been linked to depression and several other brain issues.

Research from 2018 studied the effects of fasting until the evening on levels of orexin-A, a neurotransmitter that plays a key role in focus and sleep cycles. The study found that orexin-A levels were lower at night when subjects ate, and higher in the daytime during fasting. The research suggests that fasting, at the very least, does not contribute to sluggishness throughout the day, and may in fact improve focus and energy levels.

Fasting is free. That means you either save money on food, or you’re better able to spend on healthy whole foods for mealtime, such as grass-fed beef, wild-caught fish and organic vegetables. The price of fasting is zero. And when you’re not fasting, food shouldn’t cost you a lifetime of type II diabetes and other ailments caused by processed, sugary foods.

Many people find that intermittent fasting can make their lives a whole lot easier. For starters, there’s a destressing factor involved. You don’t need to focus as much on the number of calories you’re eating, so long as you’re only eating within your allotted hours.

Time is one of the few commodities that is always in short supply. Between work, school, family, and after-work activities, there’s just not a lot of it left over. Eating can involve cooking time, preparation time, shopping time, eating time and cleanup time.

Intermittent fasting can help you reclaim some of that time because it involves doing nothing. Most diets tell you what to do, fasting tells you to not do anything. It doesn’t get much better than that.

When you cut out some of the day’s work, even if that includes eating, and focus on something else, you can decrease the stress in your life, and make it easier for you to be the healthiest version of yourself.

We’ve touched on just a few of the purported benefits of intermittent fasting. There is now lots of research happening in this space, and the results so far have been very encouraging indeed.

One of the greatest things about fasting is that it can fit into your schedule rather than the other way round. If you know you’re in for a large dinner with colleagues or family, skip breakfast and lunch. Skipping breakfast is one of the easiest ways to get started with intermittent fasting since that’s not a meal we socialize over as much as dinner or lunch. On weekdays, skipping breakfast is relatively easy to do, and this in turn can quite easily kick-start you down the route to a sixteen-hour fast.

Skipping lunch on weekdays is also pretty easy: simply work through lunch. This can also help you slip in a sixteen-hour fast without special effort. Not to mention the other added benefits: get more work done, maybe enough to leave the office a little earlier! When you stay busy, you’ll find that you often forget to be hungry. Make your excuses with your colleagues and you’ll potentially save time and money while shedding unwanted pounds. Not a bad deal.

The 16/8 method is one of the most popular and most recommended methods you can adopt for intermittent fasting. It asks that you fast for between 14 and 16 hours a day, and eat during the remaining hours. During your eating window, you can fit in two or three meals if you want to.

The reason this method is so popular is that it’s the easiest to fit into an eating schedule that you’re used to, and it’s still restrictive enough so that you don’t eat throughout the whole day. The fact that you sleep through roughly half the 16-hour fast also makes it relatively pain-free.

It’s easier than you might think to incorporate 16/8 into your everyday life. It can mean, for example, skipping breakfast, and eating lunch and dinner within eight hours of one another. So if you eat your last meal at 8 in the evening, then don’t eat again till noon the next day, and you will already have hit your 16-hour intermittent fast. Fasting means fasting - so avoid late-night snacks.

Many people don’t feel hungry in the morning, so skipping breakfast is an achievable target. Others have issues with this because they often feel hungry in the morning and need breakfast. If you’re one of these people, you can simply move your breakfast to a little later in the day. So if you eat at 10 in the morning and have your last meal at 6, you’ll still be within the 8-hour eating window.

The One Meal A Day (OMAD) method is another popular choice amongst intermittent fasters. In this regimen, your one meal is generally eaten over the course of an hour or so. You can think of it as a 23-hour fast, or a 23/1 fast compared to the 16/8 we’ve just described.

It’s an easy concept to grasp, but we should note that this approach is on the more extreme end of time-restricted eating. Your one-hour eating period is essentially a large meal with no calorie or macronutrient limits. With that said, gorging on refined carbs and processed foods is definitely not encouraged.

Nutrient deficiency does not necessarily have to be a major concern for OMAD. Since you’re still eating a meal a day, you only need to ensure that you consume sufficient proteins, minerals and vitamins by eating nutrient-dense, natural foods. Most people will get good results by only following OMAD or a 24-hour fast two or three times per week.

A key advantage of OMAD and 24-hour fasts over other, longer fasts is because you still eat a meal on the fasting day, you can still take any medications that need to be taken with food, such as many common anti-inflammatory tablets.

During any intermittent fast, you’re allowed to drink unlimited quantities of water, coffee, tea and other non-caloric fasting fluids. During the early days of your fasting journey, you may still miss the food, but having your daily cup of joe will make it easier to not eat. It can be an appetite suppressor for many people, and you won’t be avoiding the habit of consuming something in the morning or early afternoon.

One of the best tips for intermittent fasting is to stay busy. Working or scheduling appointments through lunch and staying busy is a surprisingly anti-hunger mechanism. Your cephalic phase response, in which your stomach responds to certain food stimuli, won’t be activated. If somebody slips a plate under your nose, you may find it hard to resist, but if all you’ve got is a pile of work or fifteen errands, you can just blow right through the afternoon and forget to be hungry.

Socializing over food plays a large role in most of our lives. We often convene with friends, family and colleagues for a meal. This is often an unavoidable part of human culture around the world. Trying to fight it might work for a short spell, but it’s not a winning strategy in the long run. Avoiding all social situations is not great for mental health, and will likely lead to ultimate setbacks or giving up on your intermittent fasting goals.

The great thing about most intermittent fasting methods is that they’re flexible. The days or hours of a fast can be moved around and there’s no requirement for them to be set in stone. If you’ve got an important meeting on a Tuesday, for example, and feel like you’d need a breakfast that day, you can easily change the hours you fast or move it to another day of the week.

This is obviously the main concern people have around intermittent fasting. It’s easy to assume you’ll be overwhelmed with hunger.

The most important thing to remember is that the hunger will pass. It won’t keep growing until it’s intolerable. Hunger will rarely be a persistent feeling - instead, it will come in waves. Simply ignoring it and drinking water, coffee or tea will help you cope until the wave recedes.

When you first start out with intermittent fasting, your hunger will usually be at its highest during the second or third day. After that, it’s relatively downhill from there. Many people report that their appetite actually decreases rather than increases, and with longer fasting methods, your appetite may barely be noticeable by day three or four.

During this phase, your body is being powered by fat. This means your body is eating itself, its fat, for breakfast, lunch and dinner, and no longer sending you false craving flags.

When you’re first starting out, you’re likely to struggle with fasting because your body is used to having fuel on demand. Your body will fight back against the new regimen in an effort to restore order. However, just know that, for most healthy people, you’re not putting your body through anything it can’t handle. As long as you stay the course, everything will settle into place once you’re body realizes it’s not starving, be it a matter of days or a couple of weeks.

You’ll no longer be hungry simply because it’s “lunch hour” or because you’re watching television. That’s not to say you won’t ever be hungry - you will, but it won’t be a conditioned response to an arbitrary time or occasion. Instead, you’ll be hungry because you’ll be hungry.

For the best effect, it’s often wise to combine intermittent fasting with a low-carbohydrate diet. A low-carb diet is a proven way to stabilize blood sugar and control hunger, making it easier to fast.

Let’s start with the basics here: fat is more satisfying and will keep you full for longer after a meal. Also, fat doesn’t interfere with your insulin levels, so it won’t contribute to insulin resistance in the same way that carbohydrates will.

Optimal health will be achieved by eating a variety of fats. Monounsaturated fats are found in foods such as avocados, guacamole, olives, olive oil, nuts and seeds. These fats will not only help you lay off the carbs but are also linked to a lower risk of heart disease.

Saturated fats are found in fatty meats such as grass-fed rib-eye steak, bacon, or pasture-raised chicken thighs with the skin on, as well as dairy products like butter or ghee. Saturated fats have in the past been demonized, but those fears have not been borne out. There is no reason to avoid saturated fats, and in fact, a moderate amount may lead to improved cognitive function, a healthier liver, strong bones, and a stronger immune system.

When it comes to protein, lean toward fattier cuts of meats so that you can achieve a higher intake of fat. For example, choose the dark meat of the chicken, like the thighs, over a skinless breast.

Choose grass-fed, marbled cuts of steak such as rib-eye. Select fatty fish like salmon and mackerel over lean fish like cod, and feel free to eat fish with the skin on. Broth made from the bones of beef or chicken is another great source of minerals that are vital during fasting, as are dairy products such as eggs. Nuts, nut butter and seeds are other excellent sources of protein.

Since you’ll likely be fasting to lose weight, lower insulin levels, or both, it doesn’t make a whole lot of sense to eat lots of carb-heavy foods like pasta, rice or potatoes.

It’s a much better idea to eat fewer carbs and more nutritious ones, which you can do by focusing on non-starchy veg like tomatoes, and lots of leafy greens like spinach, kale and brussel sprouts. These plants have great medicinal properties and can add loads of flavor to your food.

Lifestyle changes like intermittent fasting aren’t for everybody.

It’s simply one of many lifestyle regimens that may be suitable for you depending on your health goals. If you’re chasing a successful weight-loss method, or are looking to manage insulin resistance, you may want to give intermittent fasting a try. You may find you’re one of the many people it does in fact work for.

Nutrition should always be decided on a personal and individual basis. The most important things to focus on are still eating healthy foods, exercising and taking care of your sleep. If you try intermittent fasting and it results in added health benefits, it can be a very powerful way indeed to supplement an overall healthy lifestyle.