Intermittent fasting is a popular dieting technique that has been around for years. About two years ago the hype surrounding intermittent fasting blew up due to its promotion by several internet fitness celebrities such as the Hodge twins, and the diet has remained popular ever since. However, as many of you know, popular does not necessarily mean effective. Data is often exaggerated or misinterpreted by companies looking to sell products. It is essential to do extensive research before starting any diet in order to minimize health issues and maximize results. However, some of you may not even be familiar with this diet so before we get into what the research says, let’s first discuss what intermittent fasting even is!
Intermittent fasting is a dieting technique which involves fasting (ingesting no calories) for a specific period of time, and then consuming all of your calories during your “feeding window.” The most popular, and most studied, form of intermittent fasting is 16/8, meaning a 16 hour fast followed by an 8-hour feeding window. As difficult as this sounds, remember that you are sleeping for 6-8 of these fasted hours. Still, why would you want to limit your eating to an 8 hour period? The most common reason people choose intermittent fasting is its “fat-burning effects.” At the end of the day, a calorie is a calorie, regardless of when it is consumed. That does not mean that intermittent fasting is useless for fat loss, however. In order to fully understand the purpose of intermittent fasting, let’s take a look at all of its potential benefits, as well as the studies that this data comes from.
- Increased Metabolism (1): What many interpret as an increase in fat-burning, is more accurately a boost in your metabolism. This increase in calories burned will lead to increased fat loss over time if a caloric deficit is maintained. However, eating more calories than you are burning will still lead to fat gain regardless of when these calories are consumed. Therefore, while not an excuse to eat as many calories as you want, the metabolism boost caused by intermittent fasting can definitely aid in reaching your fat loss goals.
- Reduced Inflammation (2): One of the most common reasons for skipping the gym is inflammation or soreness. Reducing this inflammation is another benefit of intermittent fasting that can be extremely helpful in reaching your fitness goals by keeping you in the gym longer and more frequently. This also reduces the need for hepatotoxic (liver damaging) painkillers such as Tylenol (3).
- Insulin Sensitivity (4): One of the most useful, yet most overlooked benefits of intermittent fasting is its ability to improve insulin sensitivity! This means that intermittent fasting may be able to help prevent the development of Type II diabetes or limit the effects of this disease. Some of you may be thinking “I’m not diabetic or at risk for diabetes so this doesn’t apply to me.” However, what you may not realize is that insulin is an extremely anabolic hormone. Not only does insulin stop muscle catabolism (breakdown), it also increases muscle uptake of amino acids, creating an environment that is more favorable for anabolism (muscle building)! For more information on how this occurs, check out our blog on post-workout nutrition here: https://goo.gl/qh1Qgu. Some diets such as Anabolic Fasting, a diet created and popularized by fitness icon Cory Gregory, look to capitalize on the increased insulin sensitivity created by intermittent fasting, in order to effectively maximize muscle growth.
- Brain Health (5,6): On top of the more popularized fitness benefits of intermittent fasting, it also has several general health benefits including increased brain health. This neuroprotective effect is accomplished via increases in the hormone brain-derived neurotrophic factor (BDNF). Intermittent fasting has also been shown to reduce deaths via stroke.
- Heart Health (7): Intermittent fasting has also been shown to cause decreases in total cholesterol, LDL cholesterol (bad cholesterol), and blood triglyceride (fat) levels, while HDL (good cholesterol) levels were unchanged. This means that in addition to aiding with weight loss, intermittent fasting may be able to directly decrease the risk of cardiovascular disease.
- Convenience: Intermittent fasting greatly limits the time spent “meal prepping,” as your total daily calories will likely be consumed through significantly fewer meals. It also allows you to only worry about eating during 8 hours of the day, avoiding the inconvenience of fitting in a meal every two hours as many traditional diets recommend.
Note: Intermittent fasting may have other benefits that are not listed.
While the benefits proposed above sound fantastic (because they are), this does not mean that intermittent fasting is the right diet for you. These benefits are great, however, depending on your lifestyle and goals intermittent fasting may not be the right diet for you! Skipping breakfast may be very difficult for you, and while it is true that your body will adapt over time, there may still be a strong social need for you to eat breakfast. If breakfast is an important cornerstone of your day, for both physical and societal reasons, constantly depriving yourself of it may cause an unhealthy relationship with food that causes more than enough harm to outweigh the benefits of intermittent fasting. Intermittent has many benefits, but the possibility of developing an eating disorder outweighs all of them. If you feel that you are at risk for this, a diet without as strict of limits may better fit your needs.
Athletes may also struggle to follow an intermittent fasting protocol as they may exercise several times per day, requiring fuel for each workout. Eating multiple times per day has also been shown to limit muscle loss while in a caloric deficit (8). On top of this, some research suggests that eating more frequently is most beneficial for fat loss (9). Therefore, intermittent fasting may not be the optimal diet for athletes to follow. Even the casual gym-goer looking to gain muscle may not perform optimally using intermittent fasting if they workout in the morning and are not able to take advantage of proper pre and post-workout nutrition.
Overall, the most important factor to consider with all diets is sustainability. If you cannot stick to a diet long-term, it is not an optimal dieting strategy for you. Intermittent fasting may not be a diet that you are able to adhere to for very long. That’s okay, but the important thing is to find a diet that you can adhere to. Check out our blog for more dieting tips such as our blog on IIFYM (https://goo.gl/GW5TpD), and other diets that may better fit your lifestyle.
So, is it for you?
Depending on your goals, your workout schedule, your current insulin sensitivity, and how much you value breakfast, intermittent fasting may or may not be for you. If you’re still unsure, the good news is that no negative effects will come from trying it out for a few days. Give it a shot and see how applicable intermittent fasting is to your own life! Let us know how you like it or if you have any questions in the comments below and be sure to reach out on social media with any tips that could benefit our other followers @thefitexpo.