Skip meals. Normally that is not something someone who is trying to gain muscle mass would do, but according to intermittent fasting it will help you build muscle while burning fat without adding in extra cardio workouts. Rather than being a diet plan, intermittent fasting is cycle of eating. During certain parts of the day you eat, and others you fast. The fasting period goes for 16 hours; most people fast from the time they go to bed until 16 hours later as it is the most convenient time to do so. During the sectioned time that you eat, there is really no rule on what you should eat. Obviously you should stay within reason and eat healthy but it is the period when you consume all your calories for the day. Meaning that lots of food is consumed during this time period. (Gunnars, Kris)
According to Kris Gunnars, your bodies hormones go through changes when you intermittent fast. One of the biggest changes with chemicals within the body is the level of human growth hormone (HGH). The more HGH that you have in your body, the easier it is to gain muscle and shed fat- people take HGH to unnaturally boost muscle growth. Another major hormonal change occurs with insulin levels. Insulin levels are shown to decline due to intermittent fasting but insulin sensitivity is increased. This is helpful because lower levels of insulin make it easier for the body to access stored fat and use it- decreasing levels of fat in the body.
Many people believe this is an effective way to build muscle and cut fat, but is it actually proven to work?
Intermittent fasting is a relatively new practice and there is not an abundance of studies that have been performed on it. Some studies were done on athletes who follow Ramadan– a month when Muslims do not eat or drink from when the sun rises to when it sets (Gani, Aisha 2015). However, these studies were just observational and did not lead to much of a conclusion. Finally, an actual study was conducted on intermittent fasting and published on August 22, 2016. The published study named, “Time-restricted feeding in young men performing resistance training: A randomized control trial”, can be found here.
I was able to find a more descriptive outline of the study here. The study being a randomized control trial, meant that the men being studied were split into two groups; a normal diet group and intermittent fasting group. Subjects were tracked over a period of 8 weeks during which they had their caloric intake monitored and alternated upper and lower body workouts 3 times per week. The normal diet group ate whatever they wanted every single day while the fasting group only ate during a 4-hour period on their off days but was allowed to eat normally on the workout days. At the conclusion of the study, body weight, fat mass, lean body mass, bench press for 1 rep, and hip sled for 1 rep were all measured and compared to the individual’s initial measurements. This was the data published.
|Intermittent Fasting||Normal Diet|
|Body Weight||-5.5% to +2.6%||-1.4% to +2.1%|
|Fat Mass||-22.1% to +4.5%||-13.5% to +12.6%|
|Lean Body Mass||-4.0% to +4.6%||-2.5% to +3.9%|
|Bench Press- 1 rep||+4.4% to +22.7%||+4.7% to +12.2%|
|Hip Sled- 1 rep||+13.7% to +48.1%||+13.6% to +31.5%|
Instead of having an overall average or every value, these are the minimum and maximums of the value set. Without seeing all the data, it is hard to tell if any of these numbers are outliers that could skew the data in the next chart. I thought it was very hard to compare these data sets of ranges so I created a chart with the median values from the data sets above. I used median values because it only gave the maximum and minimum (because there are only two numbers it is the same as their average).
|Intermittent Fasting Median||Normal Diet Median|
|Lean Body Mass||+0.30%||+0.70%|
|Bench Press- 1 rep||+13.55%||+8.45%|
|Hip Sled- 1 rep||+30.9%||+22.5%|
While this chart may not be the most accurate representation of the data from the study, it does give a fairly decent look at the differences between the intermittent fasting group and the normal diet group. When it came to fat mass, the intermittent fasting group lost a significant percentage more than the normal diet group. When it came to the workouts, the intermittent fasting group increased their maxes by a decent amount more than the normal diet group. Mechanisms for why these things occur were stated earlier in the article: intermittent fasting raises the bodies HGH levels and lowers insulin levels while also making the insulin more sensitive. This study seems to provide evidence that intermittent fasting is effective, but was the study itself accurate?
I have a few problems with this study. One, I was unable to find how many people participated in this study, this data over a large group would mean much more than a small group. If it was a large group, then the medians would be fairly accurate and the data would show for this study that intermittent was effective. Since we do not know the size of the groups or the specific data, it is hard to conclude that. Another issue with this study is that they did not control the diets of participants. Allowing people to freely eat in a study when they are working out makes absolutely no sense. The types of food people eat while they are working out is a huge factor in how much muscle and fat they gain/lose. The study would be much more accurate if they controlled the diets of the individuals. Another thing is that this study should have went on for much longer than it actually did. Significant muscle growth and fat loss is not seen effectively over a period of 8 weeks; a longer study should have been done. I am making this study out to seem like it failed in every way possible, there could have been improvements from my point of view but it is likely the researches did what they did for a reason.
At the end of the study the researchers concluded that intermittent fasting allows for a decrease in energy intake with no effect on muscle growth. This is an accurate conclusion for this study. So should you intermittent fast? Much more research needs to be done until someone can say that intermittent fasting is PROVEN to effectively cut fat and cause no stunt on muscle growth. But at this point there is nothing saying you shouldn’t try it, if it fits your lifestyle and you notice improvements than it may be for you.