The short answer
Metabolic flexibility is your body's ability to run on fat for energy and then easily switch to burning carbs after a carb-containing meal or during hard effort. On The WarriorBabe Show, Lumen co-founders Michal and Merav link it to healthy mitochondria and to lower risk of obesity, insulin resistance and other chronic disease.
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Michal and Merav explain metabolic flexibility through mitochondria and fuel switching
Plays from 13:40 · Ep. 187: How Menopause Changes Your Metabolism and Fat Burning
The Lumen co-founders define metabolic flexibility and link it to chronic disease
Plays from 31:09 · Ep. 200: Fat Loss, Hormones and Metabolism Advice for Women Over 40
How insulin affects fat storage, and why calories still matter for fat loss
Plays from 22:19 · Ep. 200: Fat Loss, Hormones and Metabolism Advice for Women Over 40
The full answer
On Ep. 187, Michal and Merav, twin sisters with PhDs in physiology and co-founders of Lumen, start with the basics. Metabolism is your body's engine: it takes fuel, carbs or fat, and turns it into energy. At the root of that engine are your mitochondria, the powerhouses inside your cells. When your mitochondria are healthy, they do two things well:
- Rely on fat during fasting and during long, slow, steady activity, like a low-intensity workout or a long bike ride.
- Shift to using carbs after a meal, such as a bowl of pasta, or when you need high energy, like a high-intensity workout.
That ability to move between fuels based on what your body is doing and what you just ate is metabolic flexibility. The guests explain why it matters: they connect it to obesity, insulin resistance, diabetes, cardiovascular disease and neurodegenerative disease, and say it plays a role in inflammation and even lifespan and longevity. They tie this to the changes women see in body composition, especially belly fat, as they move through menopause.
The same explanation is replayed on Ep. 200, where it sits alongside a broader conversation about insulin. That episode makes a useful point: high insulin drives fat storage and low insulin helps fat burning, but calories still count, and fat loss still requires an energy deficit. It also notes that insulin resistance does not always come with obesity, so looking thin on the outside does not guarantee metabolic health. If you have concerns about insulin resistance or blood sugar, that is a conversation to have with your doctor.
The takeaway: if your body has stopped responding the way it used to, it may not be a willpower problem. How well your body switches fuels is something that can change, and understanding it is the first step.
From Nikkiey Stott and WarriorBabe's coaching. For education, not medical advice: talk to your doctor about your own health.
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Watch or listen in full
More on this topic →
1 hr 0 minHow Menopause Changes Your Metabolism and Fat Burning
With Michal and Merav
32 minFat Loss, Hormones and Metabolism Advice for Women Over 40
Episode 200 · Oct 21, 2024