Intermittent fasting is growing in popularity in fitness and health circles because it works. You may have seen an ad or heard someone talking about intermittent fasting as if it were just another trend, but the truth is, intermittent fasting has been around for quite some time. So, what exactly is intermittent fasting? Intermittent fasting is more than a diet because it doesn't necessarily restrict the foods you do and do not eat; instead, it creates a cycle of eating and not eating. There are numerous health benefits, beyond weight loss, that come with intermittent fasting. Below you'll find a guide for what to expect on an intermittent fast program.
Intermittent fasting has proven to be an effective tool for weight loss, but the benefits go far beyond that. Two of the main benefits of intermittent fasting that you may not know about are an increase in Human Growth Hormones (HGH) and lowered insulin levels. Studies show that intermittent fasting puts your body in a position to burn fat while maintaining muscle growth. One study showed a spike in HGH production during the fasting period, which is what allows fat loss while retaining muscle mass. Another benefit is a drop in insulin levels during the fasting period which lowers your risk of disease and allows your body quicker access to fat stores as fuel.
How It's Done
There are many variations of intermittent fasting, but they mainly boil down to three methods: Time-restricted eating, the 24-hour method, and the alternate day method.
#1: Time-restricted eating
The time-restricted eating method gives you a window of time to eat during the day. The most popular version of time-restricted eating is the 16/8 method. In this method, you would fast for 16 hours and eat your meals in an 8-hour window. This is the most common style of intermittent fasting and the one I use. Here's how I approach it. Let's take the typical dinner time of around 6:00pm. If I finished eating at say 6:30pm I would not have anything to eat until 10:30am the next morning. This would give me a 16 hour fast. My eating window is then from 10:30am until approximately 6:00pm for the day.
When you first start intermittent fasting you may not make it the entire 16 hours. That's OK. Do your best. When I started IF I couldn't do 16 hours at first either. Nor did I IF every day. I started very gradually with doing IF every other day and I worked up to extending my fasting time until I reached the 16 hour mark. After that I started adding more days throughout the week.
Now, after years of practice, I still utilize IF 6 days per week with the average fasting time of 16 hours. Trust me it gets easier.
#2: The 24-Hour Method
Following the 24-hour method means you fast for a full 24-hour period, but not very frequently. Typically the 24-hour method is employed on a once per week or twice per week basis. During the non-fasting days, you would eat a normal, but still healthy, meal structure. The key to the 24-hour method is to always have a non-fast day between fast days.
#3: The Alternate-Day Method
The alternate-day method requires you to do a "modified" fast every other day. Instead of fully fasting with no eating, you would significantly reduce your calories on "fast days," and eat normally on non-fast days. One of the most popular versions of this method is the 5:2 method. In the 5:2 version, you would reduce your calories for 2 days and eat normally for 5 days. For example, on Monday and Wednesday, you could limit your total calories to 500, while consuming a normal amount of calories on Tuesday, Thursday, Friday, Saturday, and Sunday. Like the 24-hour method, the key to the alternate-day method is to always put a non-fast day between your fast days.
The Scientific Health Benefits of Intermittent Fasting
Intermittent fasting may extend lifespan and allow healthier aging.
Autophagy (the recycling of unhealthy cells during fasting) may reduce the risk of cancer.
Better brain health and mental function
Decreased blood pressure and lower risk factors for heart disease
Regular fasting lowers blood glucose and insulin levels, improving insulin sensitivity and reducing the risk or severity of type 2 diabetes.
Fasting 3 days or longer resets your immune system.
7 Reasons Intermittent Fasting is Amazing for Weight Loss
#1. You Eat Zero Calories While Fasting
Eating zero calories while fasting may sound obvious. After all, it’s the definition of fasting.
But think about it. Most weight loss diets guesstimate your daily calorie intake, then have you aim for less.
Not so with fasting, though. You can’t eat fewer than zero calories. Any time you fast, you’re in a guaranteed deficit, so weight loss is more or less inevitable (if you don’t binge during eating window).
That said, you can also consider fasted workouts to kick your weight loss results up a few notches during fast periods. This is one of my favorites for weight loss.
#2: No More Calorie Counting
To lose weight most folks know they have to have a “calorie deficit.” Simply put "take in less that you expend."
And if you ever followed a diet in the past, the chances are high that you had to count calories in some form (using a notepad, an app, a food journal, or a system like “points”).
Calorie counting makes logical sense, because the purpose is to help achieve a calorie deficit.
But research shows that in reality, calorie counting usually fails long-term, especially for obese people looking to lose weight and keep it off.
There are numerous reasons, but perhaps the biggest one is that it’s complicated and unnatural.
In contrast, fasting makes achieving a deficit without counting calories easy. As long as you eat filling, healthy whole foods during your eating periods, you’ll most likely lose weight.
#3: No More Cravings
One of the biggest hurdles I hear from patients on a weight loss program is controlling their cravings. First cravings is tied to sugar and salt. Sugar is what I call a "recreational drug" and is very difficult to kick the habit.
When you cut calories and perhaps avoid certain foods, hunger is natural…right?
Perhaps, but studies show that intermittent fasting results in less hunger and more satisfaction than conventional dieting. Why? Because you are getting your sugars under control and your body is functioning more optimally.
During eating periods, you get to eat until you’re full. Some research suggests this may make fasting an easier weight loss method than traditional calorie restriction.
Essentially, you get to enjoy satisfying meals in between fast periods rather than always being hungry as with dieting.
#4: Your Body Becomes a Fat-Burning Machine
Fasting works wonders on your metabolism–your fat metabolism, to be exact.
Similar to how the keto diet boosts fat-burning, fasting for 6 hours or longer increases your ability to burn fat. When you go on diets like low carb and keto, the body still has to make glucose, even when it's not getting it from outside sources. Primarily you stopped eating carbs.
When you slow the carb intake, like really low, the body will begin to shift and turn to the available fat stores on your body for fuel. You literally become a fat burning machine!
And when you regularly fast for extended periods, the effects become even more pronounced.
In other words, the longer and more often you fast, within reason, the better your body’s ability to burn fat becomes!
#5: Greater Loss of Belly Fat
Fasting may be more effective for reducing belly fat compared to other weight loss practices
Aside from physical appearance reasons, here’s why that’s a big deal.
The presence of visceral fat, the scientific name for the fat around your organs, may indicate higher inflammation levels in your body. And it’s associated with a higher risk of heart attack and heart disease, too.
When our bodies begin to store more fat around the mid-section, it changes the function of the fat cell itself. Research tells us that as our belly fat increases the fat cell releases more pro-inflammatory cytokines.
Fortunately, by fasting, you can reduce your belly fat and your overall inflammation, which may also reduce the risk of heart problems.
#6: Short Fasts May Speed Up Your Metabolism
You may have heard that skipping meals will slow down your metabolism. But what about intermittent fasting?
Although starvation mode is a real thing, it’s not going to happen due to skipping a few meals.
In fact, one study found that during a 3 day extended fast, the study participants’ metabolism increased by a full 14% due to hormonal changes.
#7: You Can Preserve More Lean Muscle
Losing lean muscle mass is a considerable problem during weight loss.
When you shed muscle instead of fat, your metabolism, fitness, and vitality all decrease.
But research shows that regular fasting helps you hang onto healthy muscle while maximizing fat-burning.
Things to Watch Out For
Intermittent fasting is a very effective weight-loss tool, it lowers your insulin levels, and allows you to burn fat while maintaining muscle mass. However, like anything, human error can ruin the effectiveness of the method. There are 3 critical errors you can make that will undermine the effectiveness of intermittent fasting.
You don't eat healthy foods on non-fast days. It doesn't matter how much you exercise, or how well you use intermittent fasting if you are filling your body with junk during your non-fast days. Whole grains, vegetables, and lean proteins are necessary to achieve your goals no matter what program you are trying to use.
You fast too frequently. While fasting at intervals can boost your metabolism, hormone and insulin levels, and allow your body to burn its fat stores, fasting too frequently can result in the opposite. Studies show that having multiple back-to-back fasting days without a non-fasting day can cause your metabolism to slow down, your body to begin storing as much as it can in reserves (fat cells), and a spike in insulin levels. Remember to be patient. Rome wasn't built in a day, and you won't reach your goals if you're not taking care of yourself.
You eat too much on non-fast days. Sometimes, you may feel compelled to load up in calories on non-fast days. It can be easy to fall into a bad cycle of fast days and cheat days which is not the goal of intermittent fasting. Your non-fast days are better thought of as normal days. Make sure to consume an appropriate amount of calories and focus on quality foods on non-fast days and you will see the benefits of intermittent fasting start to pile up.