Fasting Weight Loss
When You’re Fasting, Does Your Body Burn Muscle Or Fat?
Let’s examine the SCIENTIFIC evidence …
Should you fast for 20 hours or more?
It depends on two things:
- How long you’re fasting and
- What you’re DOING while fasting.
In a SHORT fast — such as 16-24 hours — unlike what clueless people want you to believe — your body will NOT burn muscle.
Instead it will first burn the stored glycogen in your muscles, and then fat, and LASTLY muscle.
Second, if you’re doing some form of exercise — resistance/strength training — during the fast — then your body is “smart” enough to know that it needs to keep your lean muscle and get rid of fat instead.
There was a study where they took a group of men, decreased their calorie intake by 1,000 calories per day and also had them do weight-training 3x per week.
The result? They lost up to 20 pounds of body fat and kept all their muscle mass.
(Rice B, Janssen I, Hudson, R, Ross R. Effects of aerobic or resistance exercise and/or diet on glucose tolerance and plasma insulin levels in obese men. Diabetes Care 1999; 22: 684-691)
As I’ve also mentioned before, a study was done as long as 12 weeks where people were on a VERY low calorie diet. Only 800, liquid, calories per day! But because these people were doing weight training 3x per week (a form of resistance training) – these people kept all their muscle mass.
(Bryner RW, Ullrich IH, Sauers J, Donley D, Hornsby G, Kolar M, et al. Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate. J Am Coll Nutr. 1999;18:115-21.)
The dietary recommendations and advice given in mainstream media and most fora will have you believe that fasting is a hazardous practice. On top of wrecking your metabolism, you should expect ravenous hunger, fat gain, muscle loss, and severe mental impairment. Or so you are told.
Needless to say, people who are introduced to intermittent fasting diet concept have many fears that will make them think twice before embracing it. Fears grounded in years of a dietary indoctrination based on faulty ideas and lies. We’ve all been there.
I’ve listed the ten most common fasting and diet myths that exist to make people resistant to intermittent fasting. I’ve explained why they’re wrong and linked out to references and other resources for those who would like to read a more detailed review of the issues. I’ve also listed their origins, or what I believe to be their origins.
Listen here is the truth:
Only in prolonged fasting does protein catabolism become an issue. This happens when stored liver glycogen becomes depleted. In order to maintain blood glucose, conversion of amino acids into glucose must occur (DNG: de novo glucogenesis). This happens gradually and if amino acids are not available from food, protein must be taken from bodily stores such as muscle. Cahill looked at the contribution of amino acids to DNG after a 100 gram glucose load. He found that amino acids from muscle contributed 50% to glucose maintenance after 16 hours and almost 100% after 28 hours (when stored liver glycogen was fully depleted). Obviously, for someone who eats a high protein meal before fasting, this is a moot point as you will have plenty of aminos available from food during the fast.”
So What’s The Bottom Line?
Don’t believe “bro science”.
What is Bro Science?
It’s when people repeat “facts” about health, diet and fitness that they keep hearing … without … ever examining the evidence for themselves.
Don’t believe the hype!
- Short fasts WILL primarily burn fat for energy
- Short fasts will NOT make your body eat all its muscle
- Fasting does NOT make your body “save fat”
- Short, smart, fasting will NOT make you “go backwards” in your weight loss goals
- 24 hr or less fasting is a piece of cake compared to what your body is capable of
Basically as long as you’re eating a decent amount of protein every 24 hours — you’re gonna be absolutely fine — no muscle loss.
Watch more about the Superdiet below