Today, a question from one Muscle Evo reader on the subject of intermittent fasting and muscle loss. “I’m lifting weights three times a week,” he wrote. “Can I have a 24-hour fast twice a week? Or will I lose muscle because of this?”
Unless you’ve recently arrived from a parallel universe, there’s a good chance you’ve heard of intermittent fasting.
It involves alternating times where you don’t eat (the fasting window) with times where you do (the feeding window).
Whether you realize it or not, you already use a form of intermittent fasting (IF for short). That’s because you eat during the day and fast at night when you sleep.
The various IF protocols out there just make the feeding window shorter and the fasting window longer. And it’s the length of these fasting periods that has left some people concerned about losing muscle.
Can you fast and still have all your muscle mass remain intact? Or are you going to burn through lean tissue faster than Superman losing his powers whenever a chunk of kryptonite shows up?
Back in 2009, researchers looked at the effect of alternate day fasting in a group of 16 obese men and women.
As the name suggests, alternate day fasting involves a fast day followed by a feed day. On the fast day, you don’t go without food completely. Rather, you eat lunch — 400 to 500 calories for women and 500 to 600 calories for men — between noon and 2pm. Then on feed day, you get to eat (within reason) whatever you want.