You're eating well. You're exercising. You're being more intentional about your health than ever.

And yet, the scale barely moves.

If you've spent months (or years) wondering Why can’t I lose weight when I’m doing everything right?, it’s easy to assume you need to eat less, exercise harder, or somehow find more willpower.

But weight regulation is far more complicated than willpower.

Body weight is influenced by nutrition and activity, but also by sleep, stress, medications, metabolic health, hormones, genetics, aging, medical conditions, and the body’s biological systems that regulate appetite and energy expenditure.

That’s why I approach stubborn weight differently.

I don’t look at stubborn weight as a willpower problem. I look at it as information.

I’m Kate Rich, also known as Health Detective Kate, and when someone tells me they’re doing all the “right” things but their body isn’t responding the way it once did, I want to understand what changed and why. Sometimes that means looking beyond routine bloodwork to understand what your results may not be telling you. 

What Is Weight Loss Resistance?

Weight loss resistance is a term often used to describe difficulty losing weight despite consistent efforts with nutrition, exercise, and lifestyle.

It isn’t a medical diagnosis by itself.

Instead, persistent difficulty losing weight can be a reason to look more closely at factors that influence metabolism, appetite, energy expenditure, body composition, and overall health.

Here are four areas worth investigating.

1. Can Chronic Stress Make It Harder to Lose Weight?

Stress absolutely deserves a seat at this table—but the story is more nuanced than “high cortisol makes you gain weight.”

Your stress response affects sleep, appetite, food choices, energy, recovery, and behavior. Poor sleep can also disrupt the signals involved in hunger and fullness and make maintaining a healthy weight more difficult.

For the high-achieving women I work with, this can be particularly important.

You’re working. You’re taking care of everyone. You’re exercising. You’re eating well. You’re checking all the boxes.

But your nervous system may rarely get the message that it’s safe to power down.

Rather than assuming cortisol itself is the cause of weight gain, I look at the bigger picture:

How are you sleeping?

Do you wake refreshed?

Are you constantly wired but tired?

Are you under-eating while simultaneously overtraining?

Has your stress level changed?

Are your cravings significantly different than they used to be?

Sometimes the answer isn’t another harder workout.

Sometimes we need to understand what your body has been adapting to.

2. Can Insulin Resistance Make Weight Loss More Difficult?

Yes, metabolic health can be an important piece of the puzzle.

Insulin helps move glucose from your bloodstream into your cells, where it can be used or stored for energy.

With insulin resistance, your cells become less responsive to insulin, so your body compensates by producing more of it.

Over time, insulin resistance can contribute to higher blood sugar and increase the risk of prediabetes and type 2 diabetes.

And here’s something important:

Metabolic changes can be developing before someone has diabetes.

That’s why I don’t want to look at one isolated number and declare the investigation finished.

Depending on someone’s history, symptoms, risk factors, and previous testing, a more complete metabolic assessment may be appropriate.

3. Why Does Losing Weight Get Harder During Perimenopause?

This is the conversation far more women deserve to be having.

Many women notice that somewhere in their 40s or 50s, the things that always worked suddenly don’t work the same way anymore.

They’re eating similarly.

They’re exercising.

But their body composition begins changing—often with more weight accumulating around the abdomen.

They’re not imagining it.

Midlife weight changes are influenced by aging as well as the hormonal changes of the menopause transition. Changes in estrogen are also associated with changes in where the body stores fat, while changes in lean muscle mass can influence metabolic health.

Then layer in disrupted sleep, hot flashes, increased stress, reduced recovery, and changes in activity or muscle mass.

Suddenly, the strategy that worked at 35 isn’t necessarily the strategy your body needs at 50.

That doesn’t mean your hormones are “broken.” It means your physiology has changed—and your strategy may need to change with it.

This is why I don’t love reducing midlife weight gain to simply “estrogen dominance.”

We need to look at the whole woman.

4. Could Your Thyroid—or Something Else—Be Contributing?

Your thyroid plays an important role in regulating metabolism, and hypothyroidism can contribute to weight gain, fatigue, constipation, cold intolerance, dry skin, and other symptoms.

But thyroid dysfunction isn’t the explanation for every stubborn pound.

And neither is cortisol.

This is where investigation matters.

Depending on your symptoms and history, your healthcare provider may consider thyroid testing or evaluation for other medical contributors.

I also want to know about your medications.

Some medications used for diabetes, mental health conditions, neurological conditions, and inflammatory disorders can affect body weight.

Your health history matters.

Your timeline matters.

And context matters.

Why Eating Less Isn’t Always the Complete Answer

When weight loss stalls, the automatic reaction is often:

Eat less. Exercise more.

But continuously making your diet more restrictive isn’t necessarily the best next step.

Weight loss itself can trigger biological adaptations that make continued weight loss and long-term maintenance more challenging. Hunger can increase, energy expenditure can change, and maintaining the behaviors required for continued weight loss can become harder.

That doesn’t mean calories don’t matter.

They do.

But it means human metabolism isn’t a simple calculator.

The better question isn’t always:

How can I eat even less?

Sometimes it’s:

What haven’t we investigated yet?

What Should Be Checked If You Can’t Lose Weight?

There isn’t one universal “weight-loss resistance panel.”

Testing should be based on your health history, symptoms, medications, family history, age, and previous results.

Depending on the individual, an evaluation may include metabolic markers, thyroid function, cardiovascular risk factors, nutritional status, and other testing based on symptoms.

For women in perimenopause or menopause, the conversation may also include menstrual changes, sleep, hot flashes, body composition, muscle mass, nutrition, and whether menopause symptoms are interfering with healthy behaviors.

And sometimes testing isn’t the missing piece at all.

That’s why test, don’t guess doesn’t mean test everything.

It means ask better questions first—then choose testing that can actually change what you do next.

You Deserve Answers, Not More Guilt

If your body isn’t responding the way it once did, beating yourself up isn’t a treatment plan.

Neither is assuming that every woman needs to eat less.

Your weight is one piece of a much larger health picture.

My job as a Functional Health Practitioner and board-certified Functional Medicine Coach isn’t to blame your body or chase one magical hormone.

It’s to investigate your history, symptoms, lifestyle, existing labs, and potential contributors so we can identify what deserves attention and develop a more personalized path forward.

I’m Kate Rich, founder of Integrative Wellness Advisors and Health Detective Kate.

If you’re tired of guessing why your body isn’t responding despite everything you’re doing, let’s start asking better questions.

Book a Complimentary Root Cause Clarity Call

Frequently Asked Questions

Why can’t I lose weight even though I eat healthy and exercise?

Difficulty losing weight can involve multiple factors, including energy intake, physical activity, sleep, stress, medications, metabolic health, age, genetics, menopause-related changes, and certain medical conditions. A personalized evaluation can help determine which factors may be relevant to you.

Can perimenopause make it harder to lose weight?

Many women experience changes in weight and body composition during midlife. Aging, declining lean muscle mass, sleep disruption, lifestyle changes, and hormonal changes during the menopause transition can all contribute.

Can insulin resistance make it harder to lose weight?

Insulin resistance affects the way the body responds to insulin and is associated with metabolic dysfunction and increased risk of prediabetes and type 2 diabetes. If metabolic health is a concern, appropriate testing can help determine whether insulin resistance or abnormal glucose regulation is present.

Can thyroid problems cause weight gain?

Hypothyroidism can contribute to weight gain and symptoms such as fatigue, constipation, cold intolerance, and dry skin. However, thyroid disease is only one potential contributor to weight changes and should be evaluated within the context of your complete health picture.

What tests should I ask for if I can’t lose weight?

There isn’t one universal test panel for weight-loss resistance. Testing should be individualized based on symptoms, medical history, medications, age, family history, and previous laboratory results.

ABOUT KATE RICH

Kate Rich is a Functional Health Practitioner, board-certified Functional Medicine Coach, and founder of Integrative Wellness Advisors. Known as Health Detective Kate, she helps high-achieving women—particularly during perimenopause and menopause—investigate underlying contributors to persistent symptoms and develop personalized strategies for better health.