Why Undereating Can Be Stalling Your Weight Loss in Perimenopause
One of the most common things I hear from women in perimenopause is:
“I feel like I’m doing everything right… but the weight still won’t budge.”
You’re eating less.
Trying harder.
Skipping meals.
Cutting carbs.
Pushing through exhaustion.
Yet instead of feeling lighter and more energised, you often feel:
tired
puffy
inflamed
flat
moody
hungry at night
stuck in a body that no longer responds the way it used to
And more often than not, there’s one common denominator underneath it all:
Stress.
Not just emotional stress.
But nervous system stress.
Because the body doesn’t only respond to what you’re eating.
It responds to what it perceives as safe.
The Problem With Chronic Undereating
Many women unknowingly start under-fuelling their bodies during perimenopause.
Sometimes it starts with dieting.
Sometimes it’s being too busy to eat properly.
Sometimes it’s years of trying to “be good” with food.
But over time, the body starts adapting to low energy intake.
And this matters because your metabolism is not just a calorie calculator.
It’s deeply connected thyroid function, blood sugar stability, stress hormones and inflammation…. all the big areas that contribute to you gaining weight or finding it hard to shift.
When the body feels chronically stressed or underfed, it starts conserving energy.
This is where many women begin to feel like their metabolism has “slowed down.”
And biologically… it often has.
Stress and Thyroid Function Are Closely Linked
Stress has a major impact on thyroid function.
When the nervous system is constantly under pressure, the body prioritises survival over thriving.
Ironically, chronic stress and undereating can also reduce appetite.
Many women tell me they’re not very hungry and “I’m barely eating.”
And I believe them.
The problem is that a body running on stress hormones for long periods of time can start suppressing normal hunger cues while simultaneously holding onto weight more easily.
The body becomes more focused on conserving energy than burning it efficiently.
Poor Muscle Tone Is a Missing Piece for Many Women
Muscle is incredibly important for metabolic health.
Healthy muscle tissue helps support better blood sugar control, insulin sensitivity, metabolic rate and thyroid hormone responsiveness.
But if you’ve been chronically under-eating — especially under-eating protein — muscle tone often declines over time.
Add stress, poor sleep, hormone fluctuations, and exhaustion into the mix, and the body becomes even more metabolically inefficient.
This is why endless cardio and eating less often stops working in perimenopause.
The body doesn’t need more punishment.
It needs more support.
Weight Loss in Perimenopause Needs a Different Approach
The goal is no longer simply “eat less and move more.”
For many women, the focus needs to become:
calming the nervous system
improving thyroid responsiveness
stabilising blood sugar
reducing inflammation
rebuilding muscle tone
supporting mineral status
eating enough nourishment consistently
Because a stressed body does not feel safe to let go of weight easily.
Final Thoughts
If you feel like your body has changed in perimenopause, you are not imagining it.
Hormonal changes, stress, inflammation, poor muscle tone, and chronic under-fuelling can all work together to slow metabolism and make weight loss feel frustratingly hard.
The answer is rarely found in eating less and pushing harder.
More often, it comes from supporting the body in a way that helps it feel safe, nourished, and metabolically supported again.
Natasha Gedrim (BHSc Naturopathy)
Thyroid and Hormone Naturopath
