Insulin: Fat Storage or Muscle Tool?

Insulin Isn’t the Enemy: Why Carbs Might Actually Help You Build Muscle

Show Notes

Before we dive in, a couple of quick reminders.

My Muscle Month program starts March 29, and it only runs once a year. If you’ve been thinking about joining, this is the time. The program walks you through exactly how muscle is built and protected in midlife — including insulin, carbohydrates, mTOR, AMPK, and how to actually use these tools to your advantage.

You can join at musclemonth.com. The cost is $525, and if you’d prefer to split the payment just email me at www.joanneleestore.com.

Now onto today’s topic.

In this episode I talk about insulin, and why it has been given such a terrible reputation in the health and fitness world. For years we’ve heard that carbohydrates spike insulin, insulin stores fat, and therefore carbs must be the problem. And while there is some truth buried in that narrative, the reality is far more interesting.

Insulin is not the villain. It’s actually a tool.

Yes, when insulin is chronically elevated it can absolutely prevent fat loss. A prolonged high-insulin state is one of the biggest reasons people struggle to lose weight, particularly in midlife. Stress, sedentary lifestyles, constant snacking, poor sleep and excessive carbohydrate intake can all push insulin up and keep it there. When that happens, the body simply can’t access stored body fat efficiently.

But that doesn’t mean insulin itself is the problem.

Insulin is one of the body’s key growth signals, alongside protein, testosterone and growth hormone. It helps move nutrients into cells, including glucose and amino acids, which means it plays a direct role in muscle repair, recovery and growth. If someone completely avoids carbohydrates out of fear of insulin, they may actually be removing one of the body’s natural tools for maintaining muscle.

A big part of the conversation in this episode is about environment. Hormones respond to the environment we create. If someone is stressed, sedentary, eating constantly and sleeping poorly, insulin will behave very differently than it will in someone who is active, training, eating strategically and giving the body periods where insulin can come back down.

When used correctly, insulin can actually support both muscle building and fat loss. Timing carbohydrates around activity, especially training, can help direct those carbohydrates into muscle where they’re stored as glycogen rather than fat. Insulin also helps move amino acids into muscle tissue, which is critical for protecting muscle as we age.

I also share a little about my own experience. For many years I ate very low carbohydrate and it worked well for me. But after a major surgery in my 50s where I lost a significant amount of muscle, I had to rethink my approach. Bringing carbohydrates back in strategically allowed me to support muscle again, sleep better, recover better, and overall feel better.

The big takeaway from this episode is simple: insulin is not the enemy. It simply reacts to the environment we create. When we understand how it works, it becomes something we can use to our advantage rather than something we fear.

And if you’d like to go deeper into how all of this works — especially in midlife — Muscle Month starts March 29. You can learn more and sign up at musclemonth.com.

Also, if you’d like to catch the new weekly live sessions, head over to YouTube and subscribe to Joanne Lee Cornish so you’ll get notified when I go live.