What if the thing you’re doing to lose weight is actually the reason you can’t?
I need to talk about intermittent fasting. Not because it’s bad. Not because it doesn’t work. But because I spent months watching women in my practice do everything “right” and still not lose a single pound. And for a lot of them, fasting was the problem.
I know. Stay with me.
The Promise We’ve All Heard
You’ve seen the posts. The before-and-afters. The influencer sipping black coffee at 11am with a caption about how fasting “changed her life.” Your coworker lost 15 pounds doing 16:8. Your sister swears by it. Even your doctor mentioned it.
So you tried it. You pushed breakfast to noon. You white-knuckled past the 10am hunger. You drank so much herbal tea you could open a tea shop.
And… nothing. Or worse, you gained weight. While literally eating less.
If that’s you, I want you to know something: you are not broken. Your body is doing exactly what it’s supposed to do. It’s just responding to signals you didn’t know you were sending.
A Quick Science Bit (I Promise It’s Painless)
Here’s what nobody explains when they recommend fasting: your body doesn’t just have one system managing weight. It has several, and they don’t always agree with each other.
The one that matters most here is cortisol. You probably know it as “the stress hormone,” and yes, it does spike when you’re stressed. But here’s what’s wild: cortisol also raises your blood sugar. Even if you haven’t eaten anything.
Think about that for a second. You’re fasting. You haven’t touched food in 14 hours. But your blood sugar is up because your body is stressed.
And what happens to blood sugar that doesn’t get used? Your body stores it. As fat. Specifically, it loves to store it around your midsection, because cortisol is helpful like that.
So the chain goes: stress → cortisol rises → blood sugar rises → unused sugar → stored as fat. All while you’re technically “not eating.” Fantastic.
Why Fasting Works Beautifully for Some Women
Before I sound like I’m trashing fasting entirely: I’m not. For certain women, it genuinely works, and the science backs it up.
If you have some degree of insulin resistance (which is more common than you’d think, especially if you’ve eaten a standard Western diet for decades), fasting gives your body a break. During that 14-16 hour window without food, your insulin levels drop, and your body finally gets a chance to tap into stored glucose instead of constantly processing new fuel.
Blood sugar stabilizes. Energy evens out. Weight starts to shift.
For these women, fasting feels almost effortless after the first week. They’re not fighting their body. Their body is cooperating.
So what’s different about the women it doesn’t work for?
The Women Fasting Actually Hurts
This is the part I wish someone had told me years ago. When I was studying weight management at Emory, the research was clear, but almost nobody was talking about it publicly. Everyone was too busy posting their fasting schedules.
If you’re running on stress and bad sleep: Your cortisol is already elevated. When you add fasting on top of that, your body reads it as a threat. She’s stressed AND she’s not eating? We must be in danger. So it pumps out even more cortisol. Which raises your blood sugar. Which gets stored as fat. Which stresses you out more because nothing is working. It’s a brutal loop, and no amount of willpower breaks it. Your hormones will win every time.
If you’ve spent years dieting on and off: Your metabolism has already learned to be cautious. It’s been through restriction before, and it adapted by slowing down to conserve energy. When you introduce fasting, your body doesn’t think “great, time to burn fat!” It thinks “oh no, here we go again” and slows down further. You’re eating less and burning less. The math never works in your favor.
If you’re in perimenopause or menopause: This is a big one. Extended fasting can genuinely interfere with your estrogen and progesterone levels during a time when those hormones are already doing their own thing. For women in this phase, even a gentle overnight fast of 12-13 hours is usually the max that makes sense. Pushing beyond that isn’t discipline. It’s disruption.
The Part Nobody Wants to Hear
Here’s what all of this comes down to, and it’s frustrating, I know:
Whether fasting helps you or hurts you depends almost entirely on your hormonal profile.
Not your willpower. Not your discipline. Not how badly you want it. Your hormones.
Two women can follow the exact same fasting protocol. Same hours, same food, same exercise. One loses weight steadily. The other gains. And neither of them is doing anything wrong.
This is why I get a little twitchy when I see blanket recommendations. “Just do 16:8!” “Skip breakfast, it’s easy!” Maybe for you. But the woman reading your post might have a completely different hormonal situation, and your advice could genuinely set her back.
What Actually Works (For Pretty Much Everyone)
Okay, so if fasting isn’t the universal answer, what is?
Honestly? It’s less exciting than a trendy protocol, but it’s real:
Eat real food. And eat enough of it. I cannot stress the “enough” part. So many women I work with are chronically undereating, especially protein. Your body needs fuel to function. When you don’t give it enough, it panics. Refer back to the cortisol section for what happens next.
Prioritize protein at every meal. This isn’t a bodybuilder thing. Protein stabilizes blood sugar, keeps you full, and supports your metabolism. If you’re eating a salad with no protein and wondering why you’re ravenous by 3pm, there’s your answer.
Move your body, but rethink what that means. I used to think more cardio was always better. I’d run and run and wonder why nothing changed. Turns out, strength training does more for your metabolism than an hour on the treadmill. And excessive cardio? That can raise cortisol too. (I know. It feels like everything raises cortisol. Welcome to being a woman in the modern world.)
Pay attention to YOUR timing. When you eat matters, but the “when” is different for everyone. Some women do great with an earlier eating window. Some need breakfast within an hour of waking up. Some genuinely thrive skipping it. The point is: what works for your friend’s body might not work for yours.
So… What Do You Do With This?
If you’ve read this far and you’re thinking “okay Maria, this is great, but HOW do I know which one I am?” — that’s the exact question that got me obsessed.
Because I realized the problem isn’t lack of information. It’s that the information isn’t personalized. We’re all reading the same generic advice and trying to make it fit bodies that work very differently.
That realization is actually why I’ve been building something. A free quiz that looks at your specific situation and helps you figure out whether fasting is right for your body, or whether a different approach would work better. Because once you understand your own hormonal profile, the guesswork disappears. You stop fighting your body and start working with it.
I’ll share more about it soon. For now, if the only thing you take from this article is “what works for her might not work for me, and that’s not a failure” — that’s everything.
Your body isn’t the problem. The one-size-fits-all advice is.
This article is for informational purposes and reflects my understanding as someone certified in weight management. It’s not medical advice. If you’re dealing with significant hormonal concerns, a good endocrinologist is worth their weight in gold.
