A Breakthrough in Fat Loss and Muscle Growth
Scientists may have found a way to build muscle while burning fat. New human and primate data suggest this “impossible” body recomposition is around the corner.
We might be extremely close to developing treatments that simultaneously blast away fat and build muscle.
Now, I understand why you might be skeptical, or even afraid to hope that something like this is possible.
But the data from both humans and monkeys suggests that it very much is possible… and maybe even around the corner.
But that may provoke a second layer of skepticism: even if it’s possible, is it actually desirable?
After all, in nature and medicine, there’s rarely a free lunch. I’ll absolutely address that concern, along with the limitations of the data, as we move through this scientific story together.
But first, I want to plant a seed in your mind.
Our bodies were shaped by evolution to meet the demands of a very different environment, one defined by the constant risk of food scarcity and starvation. As a result, we did not evolve to easily pack on muscle while shedding fat.
In fact, evolution favored the opposite.
Body fat was evolutionary security. Energy insurance.
Muscle, at least beyond what was necessary, was energetically expensive. From a survival standpoint, you don’t want more of it than you truly need.
Obviously, our priorities have changed.
Now, I won’t presume to speak for you; but speaking for myself, I’d love to gain 20 pounds of muscle while losing the little body fat I have left, especially if doing so actually improved my health as well.
In today’s letter, I want to give you a glimpse of the future: a future in which we unlock a few deeper secrets of metabolism and begin to realize a new era of human bioengineering.
And, I promise, that future may be much closer than you think.
Roadmap
As a quick roadmap to the rest of this letter:
Biological pathways: Activin A and Myostatin
Preclinical data: Muscles, Monkeys, and mABs
Human data: Results of a double-blind, controlled trial.
Present practicals & protocols: options available today that can help you optimize body composition and physical performance
Biological Pathways
Let’s return to the idea that, evolutionarily, muscle is expensive.
While our bodies do have systems that can build muscle quite rapidly, they’re often held in check by a “brake,” or “breaks.”
If you pause to think about it, that’s not so surprising.
Consider other animals, like a tiger or a gorilla. With relatively little effort, they can put on maintain immense amounts of muscle.
The reality is that we, too, have far greater potential for muscle growth than most of us realize. It’s just chronically restrained to prevent us from burning too many calories.
I know…ironic.
And, as with most things in biology, evolution tends to build in redundancy to ensure robustness.
So instead of relying on a single mechanism, our bodies use multiple overlapping systems to suppress excessive muscle growth. In this case, that includes several circulating molecules that act as muscle growth “breaks.”
Two of the most important are myostatin and activin A.
Interestingly, they bind to similar receptors.
The logic, then, is straightforward: while blocking either one of these molecules can enhance muscle growth by releasing the brake, blocking both simultaneously may provide a greater capacity for muscle building.
In theory, this should unlock a level of muscle growth most humans have never experienced.
But what actually happens when you test this, in monkeys and in humans?
In the rest of this letter for StayCurious Metabolism premium members, we dive into:
The biology behind these muscle-building therapies
What happens when you combine them with GLP-1 weight loss drugs
What we know about safety and side effects.
Then we get practical. I’ll walk you through strategies you can use today, including:
A nutritional intervention proven in a multiple randomized controlled trial to blast visceral fat
A weird way to potentially increase energy expenditure through thermogenesis (heat production)
A mitochondrial hormone that might be the closest we’ve ever come to a true exercise mimetic.
If you’re someone who values nuanced science and wants to stay on the cutting edge of metabolic health, this is exactly what we do inside StayCurious Metabolism. Find out why members consistently call it the best investment they’ve made in their health.
