What is Intermittent Fasting?
If you have ever heard of intermittent fasting, or intermittent eating, it is described as periods of food restriction and feeding. Intermittent fasting can be various protocols such as 12/12, 16/8, 20/4, 24/24 or whatever protocol fits your lifestyle; for clarification the ratio is fasting/feeding. Many use Intermittent Fasting (IF) as a weight maintenance and/or weight loss strategy, as well as technique to improve cognitive function.
Intermittent Fasting and Muscle
What does the science say about intermittent fasting? In a very novel recent study, researchers looked at the impact of a 15:9 intermittent fasting protocol on Muslim bodybuilders practicing Ramadan. The study was conducted for the duration of Ramadan, which happens to be 29 days.
The participants were divided into two separate groups, one group that trained during their “feeding” period and one group that trained at the end of their “fasting” period. The guys in the study were eating maintenance calories and were performing a maintenance training stimulus. What they found was that during the course of the 29 days neither of the groups lost body weight, but that makes sense because they were at maintenance calories. However, there was a trend for the reduction in body fat, while they maintained lean body mass.
In addition to the Ramadan study I was just speaking of, there was another great study done that looked at the effects of intermittent fasting on body composition. This was once again another Ramadan study, however this one was conducted in elite power lifters. Once again, the guys in this study were consuming maintenance calories and performing a maintenance training stimulus. What the researchers found here is that from pre-Ramadan to one-month post Ramadan the subjects actually gained lean mass and maintained fat mass.
If you have read the article on insulin sensitivity, you may recall an enzyme called AMPK. AMPK is the cells fuel gauge that helps regulate the energy used in the cell. During periods of fasting, AMPK increases causing your body to breakdown fat for energy and increase insulin sensitivity. Therefore, during the fast you are utilizing stored body fat as energy and when you eat you are more sensitive to the food (specifically carbohydrates) that you consume. This will allow you to store the food as energy and not body fat. This shows that intermittent fasting may be great for overall improving body composition, but how do you overcome the hunger pains?
Intermittent Fasting and Hunger
One question that we commonly hear regarding intermittent fasting is how it affects hunger. Most people cannot imagine only eating during scheduled times because they fear that they will experience intense hunger that will affect their day. This thought often prevents people from giving intermittent fasting a try, but is hunger actually an issue? Maybe it is more of a psychological relationship with food that makes the idea of not being able to eat scary. I am here to present some information on why intermittent fasting gets easier as one progresses. In 2013, Dr. Varady et al. conducted a study that looked at fullness and the feeling of satisfaction in healthy active people. Participants in this study were divided into a control group that didn’t fast and an experimental group that fasted every other day by lowering calories to 500 on fasting days; what we term alternate day intermittent fasting. These participants followed this protocol for 12 weeks and were asked to rate their fullness and satisfaction throughout this period. The results found are expressed in the graph below.
Intermittent fasting appears to have an adaptation period as well. Researchers from the study above found that fasting became easier over time! This is likely due to the individuals adapting to the diet! This means that when you try intermittent fasting, you need to be patient. As you become more and more adapted to your fasting period, your desire to eat will likely lower. Additionally, you will probably begin to consume less calories than you previously did. Not only does intermittent fasting offer weight loss benefits, but it has been speculated that fasting also improves cognitive function. There are a number of ways that this can happen, however one of the most obvious is the fact that once you have become adapted to not eating for extended periods of time you tend to not think about food. Ask yourself this question, “how productive could I be if I didn’t have to worry about eating every three or four hours?” Like I said before, this idea does take some time to adjust to, however you’ll be surprised with the benefits and results!
Obviously, there is still a lot of research that needs to be done in the field of intermittent fasting on its effects on strength, power, hypertrophy, performance and overall body composition. Up until now, many have only researched its health benefits, which include the ability to reduce markers of cardiovascular disease (high blood pressure, high total cholesterol, high LDL cholesterol, elevated triglycerides, atherosclerosis), as a cancer therapy with calorie restriction, and neurological and cognitive benefits. The research is quite promising when it comes to intermittent fasting and improvements on quality of life.
You can utilize intermittent fasting as an approach to maintain lean muscle mass and decrease fat mass. If you are doing intermittent fasting everyday, I would refrain from fasting longer than 16 hours in fear of potentially losing muscle mass. However, if you are only fasting a few times per week, then you can utilize longer fasts to help increase fat loss. In addition, a way that one can make this intermittent fasting adaptation period easier is to start with a small fast and progress to a larger fast. For example, start with a simple 12-hour fast and schedule the majority of the fasting period while sleeping. Then increase the fasting period each day in small increments until you become adapted to the diet. From that point you’ll be acquainted with the idea of having periods of fasting, therefore it will be easier to fast for longer durations of time.
Stay tuned because my team of scientist and myself are in the process of developing a study where we will investigate the direct effects of meal timing on body composition. This seems to be one of the biggest concerns when it comes to intermittent fasting; people want to know what is the BEST protocol. That is something that we want to figure out for YOU!