The Truth About Slowed Metabolism: How Long-Term Calorie Deficits Hurt Your Body

Does It Feel Like Your Metabolism is Broken?

You’ve been eating less, working out more, but the scale won’t budge. Maybe you’ve even gained weight, despite being in a calorie deficit. Sound familiar?

If so, your metabolism may have slowed down—not because you're getting older, but because your body has adapted to long-term calorie restriction.

But here’s the truth: Your metabolism isn’t broken. It’s just in survival mode. And with the right approach, you can reset it and get back to burning fat efficiently.

Many women over 40 make the mistake of dieting too aggressively for too long—thinking they need to keep cutting calories to lose fat. Going as low as 1000 calories (Yikes!)

But the longer you eat too little, the more your body fights back. (And holds onto that stubborn fat out of survival...)

So let’s break down the real science behind a slow metabolism—and how to fix it.

What is Metabolism and How Does It Work?

Your metabolism is the process of turning food into energy. It’s responsible for keeping you alive, fueling your workouts, and burning calories even at rest.

The three main parts of metabolism:

1️⃣ Basal Metabolic Rate (BMR) – The calories your body burns just to stay alive (breathing, digestion, brain function, etc.).
2️⃣ Thermic Effect of Food (TEF) – Calories burned from digesting and processing food.
3️⃣ Activity Energy Expenditure (AEE) – Calories burned from exercise and daily movement (like walking, fidgeting, or standing).

Your BMR accounts for 60-70% of the calories you burn daily. So if your BMR drops, fat loss becomes much harder—even if you’re eating less.

And that’s exactly what happens when you stay in a calorie deficit for too long.

Does Your Metabolism Really Slow Down as You Age?

You’ve probably heard that aging = slow metabolism. But that’s only part of the story.

The real reason metabolism slows with age? Muscle loss and hormonal changes.

• Muscle burns more calories than fat—so the less muscle you have, the fewer calories you burn at rest.

• Estrogen drops in perimenopause/menopause, leading to fat storage (especially around the belly).

• Thyroid function can decline, further slowing metabolic rate.

But here’s the good news: Metabolism is adaptable. You can reverse these effects by focusing on muscle-building workouts and strategic nutrition.

What is Metabolic Adaptation?

Your body is wired for survival. When you eat too few calories for too long, your metabolism adapts to conserve energy by:

❌ Lowering BMR – You burn fewer calories at rest.
❌ Reducing NEAT (Non-Exercise Activity Thermogenesis) – You move less without even realizing it.
❌ Increasing hunger hormones (Ghrelin) and lowering fullness hormones (Leptin) – You feel hungrier and more fatigued. (Girl you've been tired for a reason! Not just from daily work and taking care of the family.)
❌ Breaking down muscle for energy – Less muscle = even slower metabolism.

This is why chronic dieters struggle with cravings, binge eating, and yo-yo dieting—your body is literally fighting against you.

The more you restrict calories, the harder it becomes to lose fat. Your body enters “starvation mode”—where it holds onto fat for survival.

Signs Your Metabolism Has Slowed Down

If you’ve been dieting for months (or years) and notice any of these, your metabolism may have adapted:

🚩 You’ve hit a fat loss plateau despite eating low calories.
🚩 You feel exhausted, cold, or moody.
🚩 You’re always hungry and craving sugar.
🚩 Your workouts feel harder, and you’re losing strength.
🚩 Your periods are irregular, and your sex drive is low.

If this sounds like you, it’s time to stop cutting calories and start repairing your metabolism.

How to Reverse a Slowed Metabolism

The key to fixing a poor metabolism? Eating more—strategically.

Building Muscle to Boost Metabolism

✅ Strength training 4-5x per week to increase muscle mass.
✅ Prioritizing protein (0.8-1g per pound of body weight) to preserve lean muscle.
✅ Avoiding excessive cardio, which can worsen muscle loss and cause more stress in your body.

Think of your metabolism like a fire. If you barely feed it (low calories), it burns out. But if you feed it consistently (proper nutrition & muscle-building workouts), it keeps burning strong.

Women often fear eating more because they think they’ll gain weight. But strategic refeeding can actually help reset metabolism and make fat loss easier for you.

When you gradually increase calories (Reverse Dieting), your body:

✔️ Burns more calories naturally
✔️ Stops hoarding fat for survival
✔️ Regulates hunger hormones
✔️ Increases energy and muscle tone

It's Time to Take Control of Your Metabolism

If you’ve been stuck in diet mode, exhausted, and frustrated, your metabolism isn’t broken—but it does need a reset.

Your body wants to work with you—you just have to fuel it the right way.

Want a step-by-step plan to restore your metabolism?
Let’s work together! 👉 Apply for coaching here.

FAQs About Metabolism and Calorie Deficits

Q: Can I fix my metabolism after years of dieting?
✅ Yes! With reverse dieting, strength training, and proper nutrition, you can restore a healthy metabolism.

Q: Will eating more make me gain weight?
✅ Not if done strategically. Increasing calories gradually prevents unnecessary fat gain while improving metabolic function.

Q: How long does it take to speed up metabolism?
✅ It varies, but most women see improvements in 4-8 weeks when following a proper plan.