Intermittent Fasting, often referred to with the shorthand “IF,” is a strategy for losing weight that works by restricting your calorie intake to a specific timeframe. By only consuming calories within a narrower window of time, you inherently consume fewer calories within a given day, which typically results in a calorie deficit. Additionally, proponents of intermittent fasting argue that practicing IF can also help your body become more efficient at processing energy, aiding in long-term well-being.
Often pitched as an “eat what you want and still lose weight” diet, there’s quite a bit of skepticism about intermittent fasting’s effectiveness as well. After all, the general rule of thumb is that if something sounds too good to be true, it probably is.
Naturally, this raises a specific question: does intermittent fasting actually work?
What is Intermittent Fasting?
In its simplest definition, intermittent fasting is an eating pattern that alternates between periods of fasting and periods of food consumption.
The most common approach to intermittent fasting is known as a 16:8, or 16-hour, fast. With this method, you have an eight-hour window each day in which you can consume food. For example, you may only eat between the hours of 11 AM and 7 PM; from 7:01 PM to 10:59 AM the next day, you don’t consume anything caloric, meaning that things like water and coffee are still on the table.
While the 16:8 method is typically considered the most straightforward and convenient variation of intermittent fasting, there are other options as well. Another popular strategy for intermittent fasting is to have a 24-hour fast once or twice per week in which you consume nothing caloric, but eat normally the other days of the week.
Unless you over-compensate by binging during eating hours IF typically results in a caloric deficit– meaning that your body is burning more calories than it’s consuming– which will typically result in weight loss for most people.
What are the benefits of Intermittent Fasting?
In general, fasting is something that has been practiced by humans for millennia. It’s a common practice in several religious and well-being traditions, and has proven to be healthful in a variety of ways.
As Roger Collier cites in “Intermittent fasting: the science of going without,”
There is indeed a large body of research to support the health benefits of fasting, though most of it has been conducted on animals, not humans. Still, the results have been promising. Fasting has been shown to improve biomarkers of disease, reduce oxidative stress and preserve learning and memory functioning, according to Mark Mattson, senior investigator for the National Institute on Aging, part of the US National Institutes of Health.
Specifically, fasting has been associated with:
- Increased levels of Human Growth Hormone (HGH), which helps to burn fat and build muscle
- Lower insulin levels and improved insulin sensitivity
- Aid in cellular repair
- Improved cognitive function and focus
Additionally, one of the things that proponents of intermittent fasting frequently cite as a selling point for this eating pattern is that it is quite simple. Often, the diet and eating plans that are advised for losing weight and building muscle can be quite complex, and require an extensive amount of meal prep and planning in order to be successful. With intermittent fasting, since you aren’t being as strict with what you’re eating but rather when you’re eating, there is less preparation and rigidness that goes into it, which gives people a greater sense of freedom and ease. If you run out of time one morning and can’t pack your kale and grilled chicken lunch, for example, you’re not going to blow your progress by grabbing a burrito during your eating window.
What are the drawbacks of Intermittent Fasting?
First and foremost, people with a history of eating disorders or who struggle with severe body image issues should be very cautious with attempting intermittent fasting and should likely only do so under the supervision of a medical professional.
Depriving yourself of food and only eating during a set window can be a very triggering act for those who struggle with binging and purging. If you do struggle with an eating disorder, please work with your physician or the National Eating Disorder Association to make sure you are healthy first and foremost and do not alter any medically-advised diet plans or eating routines without consulting your doctor.
With that being said, many people who engage in intermittent fasting will see early results that taper out or plateau after a while. One of the main reasons for this comes back to the fact that “eating what you want and still losing weight” is a concept that is too good to be true. While a simple calorie deficit can help lose some weight initially, if you aren’t getting adequate nutrients or consuming a well-rounded diet, your body is not going to operating optimally.
Because of this, it is more accurate to refer to intermittent fasting as an eating pattern than a diet; you’re only going to have significant success with this method if the foods that you’re eating during your calorie-consumption windows are actually doing a solid job of fueling your body. To put it bluntly, if you’re eating like crap, you’re going to feel like crap even if you’re only eating a little crap at a time.
How to be successful with Intermittent Fasting
As alluded to in the previous section, if you’re going to be successful with intermittent fasting, you need to be intentional about how you’re approaching it.
During the hours in which you are consuming calories, you want to make sure that you’re eating a well-rounded, nutrient-dense diet. Personally, I recommend eating one that is low in simple carbs and refined sugars, and high in fiber, protein, omega-3 fatty acids, and vegetables. You can bolster your dietary intake with daily multivitamins or nutritional supplements like Athletic Greens, but it’s important to not rely upon these as your exclusive source of nutrition. The foods you eat are still key.
It’s also critical that you remain physically active and engage your muscles regularly while practicing intermittent fasting. As with any lifestyle that includes a calorie deficit, you’re going to be burning up more than fat, and muscle loss is possible (in fact, it is probable) while you’re practicing intermittent fasting. Exercise and muscle engagement are necessary to maintain your body and health while you’re losing weight. If you’re exercising regularly while also doing intermittent fasting, keep in mind that building muscle can cause you to weight more– so if you see your waistline getting smaller but your weight staying the same on the scales, that means it’s working and that you’re just building more lean muscle while you’re burning fat.
Avoiding extremes is also quite important to being successful with intermittent fasting. You don’t want to eat too much or too little during your window of caloric consumption, and you don’t want to narrow down your consumption time frame into dangerous levels. With either too much or too little food, you’re not going to be doing your body any favors and neither is good for your health.
My experience with intermittent fasting
I decided to give intermittent fasting a try after realizing that I needed to shift myself away from the Slow Carb diet. I should say that the Slow-Carb diet was working for me– I was definitely losing weight– but my stomach was having a hard time. I’m not entirely sure why, but it was causing me to get quite nauseous to eat high levels of protein first thing in the morning. When I decided to take some time away from the Slow-Carb plan, I wanted to give intermittent fasting a try simply because it worked with my schedule.
At first, I lost about a pound a day on IF, which is quite good. This has plateaued after about 10lbs lost, but I’m also in the gym with more regularity and have seen improvements in my muscular definition, which could account for why I’m no longer “losing weight.”
For me, the biggest challenge with intermittent fasting is that I am often so hungry by 11 AM (when my intake window starts) that I have a hard time focusing at work. I workout first thing in the morning, so I’m already going into my workout in a fasted state, and my body is so desperate for fuel to recover from the workout that I honestly just don’t feel great until I get something in my body. Because of this, I’ve had to start eating a protein bar first thing in the morning, so I’m technically deviating from a strict intermittent fast.
Despite the challenges, I will say that I’ve been pretty happy with the results of IF so far, and I am planning on sticking with it in my slightly modified way for the time being– while the morning protein bar might be an issue from a purist perspective, it also allows me to be able to work without shaking and feeling like I’m going to pass out before I stop and have my first meal of the day.
Moving forward, as long as my stomach doesn’t protest too much, I’m planning on combining intermittent fasting with the slow carb diet. I no longer get nauseous at the thought of eating eggs and black beans, so I think my stomach will be able to handle doing it, but we’ll see. Since IF is already restricting my caloric intake, I’m also not going to be super strict with the Slow Carb diet– I’d say that I’ll be sticking to it about 75% since I’m still going to need my post-work frozen yogurt or my stressful workday fried chicken here and there.