What is Intermittent Fasting, and why are you doing it?

Intermittent fasting in layman’s terms is basically having a period of time each day where you don’t eat. The concept is involves forcing the body to burn fat stores for energy during the fasted period of the day. To understand how this is possible, you first need a very basic understanding of how the body burns calories for energy. The body will always prefer burning carbohydrates first, then fats, and then proteins. Carbohydrates quickly break down into glycogen which your body will always burn before it digs into fat reserves for energy. If there is no available glycogen, your body will convert fat stores into energy…which is what we want! However, at some point if there is still no available glycogen, your body may begin to dig into intramuscular fat and catabolize your muscle (protein). This is what we don’t want!

Now that you understand the priority of your body’s energy usage, you can understand that depleting glycogen reserves will cause your body to burn more fat for energy. Through much research, case studies, and personal tweaking, a nutritional consultant and personal trainer named Martin Berkhan developed the “LeanGains” program. Berkhan, who operates a blog (www.leangains.com), has essentially written the book on how to effectively use I.F. for fat loss while gaining muscle. He has found that a fasting window of 16 hours for men, and 14 hours for women is the most efficient way to burn fat. This fat burning is further intensified by exercise activity to increase energy expenditure.

This is going to be a massive over-simplification, but right after you eat, your body stops burning fat. It doesn't need to burn fat because it has energy available through the absorption of carbohydrates. Even if what you eat is low carb, your body will still convert that into glucose and essentially cause fat burning to come to a screeching halt. A few hours after eating, your body might begin to burn a very, very small percentage of fat, but still almost all carbohydrate. After sleeping for 8 hours, you are burning more fat, for ease of explanation, let's say 50/50. After 16 hours of fasting, you are burning mostly fat. This is why 14-16 hours is the sweet spot.

Ok, so practically…how is all of this going to work?

Well, I am going to try this experiment Monday – Friday over the next few weeks. I’ll be tracking my progress each week with measurements and pictures. Additionally, I’ll keep track of my exercise loads at the gym. Weekends I’ll break the cycle and eat whenever I feel like it. Here is my tentative schedule starting out with a 14 hour fast. I’m trying to ease my way into the 16 hour window. Technically 14-16 hours is probably the most efficient time frame, so I want to get there…I’m just ramping it up slowly.

4:50 AM: I’ll take 10g of BCAA’s (Branch Chain Amino Acids) 5-15 minutes before my workout.
5:00 – 6:15 AM: Weightlifting session.
7:00 AM: I’ll take 10g BCAA’s.
9:00 AM: I’ll Take 10g of BCAA’s.
10:00 AM: Start of the 10 hour feeding-window. I’ll eat A LOT of food at 10am.
8:00 PM: Last meal before the 14 hour fast. Will eat dinner and finish it off with some Casein protein.

* Note that the BCAA's don't count against the fast. They are supplemented pre-workout, post workout, and one more time prior to beginning the feeding phase. This is done to promote continued protein synthesis.

Hopefully I can adjust and adhere to this schedule fairly easily. Once I can, I’m going to slide meal #1 to 11:00am, and then eventually 12:00pm so that I’m hitting a 16 hour fasting window and an 8 hour feeding window.

One final thought. I am fully aware that this flies in the face of most everything people have heard about nutrition. You also have to realize that this is a targeted plan with very specific goals. If I am training for performance, there is no way I would be doing this. I would be in a phase of carbohydrate loading so that I had full energy reserves to train, etc. With this plan I am specifically focusing on body fat reduction while attempting to gain muscle mass. This will be a challenge, but I’m very interested to see how it goes.

- Matt, aka, Major Pain