Hey, and welcome to my science based guide to muscle sparing fasting for weight loss.

Read this guide all the way through and you'll know exactly how the amazing science behind muscle sparing fasting can help you laser-target that stubborn body fat WITHOUT destroying any of your lean body mass in the process.

What is muscle sparing fasting?

Muscle sparing fasting is a low-calorie diet also known as "protein-sparing modified fasting".

The diet itself is basically a standard water fast that allows you to eat just enough protein to prevent any loss of your lean body mass.

It is one of the fastest science-based weight loss methods that allows you to get rid of that stubborn body fat WITHOUT destroying a lot of your lean body mass as well.

And it's true. Muscle sparing fasting doesn't really look like an easy diet on the surface.

But after you see how the science behind muscle sparing fasting works to your advantage, you'll understand that muscle sparing fasting may actually be easier to do than most of the of the "easier" weight loss diets on the market.

So let's take a closer look at how exactly muscle sparing fasting works.

How does muscle sparing fasting work?

The single most important benefit of muscle sparing fasting is its ability to deliver rapid fat loss without any muscle loss.

And like I said, during a muscle sparing fast you're only allowed to eat a small amount of protein.

But that tiny amount of protein is more than enough to fully reverse the unnecessary destruction of your muscle mass that happens on many other weight loss diets.

Now, even though you're eating some protein and not fasting completely, you'll still only be getting in a few hundred calories a day at most.

So ultimately, muscle sparing fasting is able to deliver fast and big weight loss results because it's such a low calorie-diet.

But let's take an even closer look at how all this protects your muscles during rapid fat burn.

How does muscle sparing fasting protect your muscles?

If you didn't eat any protein during your next muscle sparing fast (and basically did a pure water fast), your body would keep losing a small amount of "structural protein" every day[1].

Structural protein are the basic building blocks of your muscles and vital organ tissues.

Without any energy coming in as food (on a pure water fast), your body is forced to burn off some of those structural protein from your muscles and other vital tissues for energy.

And by allowing you to eat a tiny amount of protein, muscle sparing fasting solves the single biggest issue of water fasting, a rapid destruction of your muscle mass.

Which brings us right to the most important rule of muscle sparing fasting...

How much protein do you need to eat during a muscle sparing fast?

When it comes to eating protein during a muscle sparing fast, you need to hit the "sweet spot".

You need to eat just enough protein to fully reverse the destruction of your lean body mass.

But you also want to eat as little protein as possible, so you can keep your fat burn rate sky-high.

So, how much protein per day do you ultimately need to eat during a muscle sparing fast?

Science[2] says, all you need is around 0.6 grams of protein per pound (or 1.3 grams of protein per kilogram) of your "ideal body weight".

On to the next burning question most people ask about muscle sparing fasting.

Is muscle sparing fasting safe?

Well, the truth is, "muscle sparing fasting" was associated with over 60 deaths in the 1950's.

The problem was, those unfortunate people used very low-grade liquid proteins for their muscle sparing fasts

Over the decades that followed, muscle sparing fasting was proven to be safe in over 10,000 medically-recorded cases[3], provided that:

You're a healthy person who isn't suffering from any health issues (only your doctor is qualified to confirm that), you don't do muscle sparing fasts longer than 3 months and that you do them under supervision of a medical professional.

Muscle sparing fasting reduces hunger and appetite

An eye-opening study[4] has proven that a 500-calorie muscle sparing fasting diet was able to reduce appetite, hunger, anxiety, and preoccupation with food in comparison to a 1200-calorie weight loss diet.

Just think about this for a moment.

Just because you're allowed to eat more than twice as much food on some standard weight loss diet (1200 calories), you could still suffer from more hunger and cravings than on a very low-calorie muscle sparing fast (500 calories).

I was quite amazed when I first found out about this. But according to science, hunger really isn't all that about how much you eat, but much more about what you eat.

And as far as hunger and cravings are concerned, I have yet to see a diet that can put the brakes on your appetite while still allowing you to lose weight at a ridiculously high rate.

Which brings us right to the next question:

What kind of weight loss results can you expect?

According to one study[5] that took a closer look at muscle sparing fasting and weight loss, it's possible to lose up to 2 pounds (1 kilogram) of weight PER DAY.

And the best part?

Knowing that no matter how much weight you ultimately lose (and how quickly you lose it), you won't be losing any muscle mass (or damaging your vital organs), even as your body fat melts away faster than on a huge majority of diets out there.

How many weight loss diets do you know that can do the same and can actually back such claims with modern science?

Well, let me wrap things up with a weight loss tip you can use during a muscle sparing fast to literally skyrocket your fat burn rate:

Caffeine DOUBLES the release of fat from your body fat reserves

According to science[6], taking caffeine during a muscle sparing fast can literally DOUBLE the release of fat-calories from your body fat reserves.

And what do you think happens next?

Because you'll be eating so few calories during a muscle sparing fast, your body will hungrily burn away those newly released fat-calories for energy.

(If you're interested in learning more about how caffeine actually works for weight loss and how many calories it can help you burn, you can read my science based guide to boosting weight loss with caffeine).

So not only does muscle sparing fasting do an awesome fat burning job in and of itself, caffeine can boost this state of high fat burn even further.

Written by

Rok Sprogar is a NASM Certified Nutrition Coach (NASM-CNC) and a NASM Certified Weight Loss Specialist (NASM-WLS) who has been contributing highly actionable and science-based content to Leanhigh.